Antenna Rotator controller compatible with tracking software

Simple controller for homemade (or commercial) antenna rotator. Manual command or USB via computer tracking software: Orbitron, SatPC32 ...

Mar 5, 2020

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tracking

remote control

robots

Components and supplies

Rotary Encoder with Push-Button

Relay Module (Generic)

Breadboard (generic)

Rotary potentiometer (generic)

Arduino UNO

Power MOSFET N-Channel

Apps and platforms

Arduino IDE

Project description

Code

Potentiometer calibration procedure

arduino

AZ / EL Potentiometers limit calibration PROCEDURE for displaying the correct antenna angles and rotation limits ( 0-359ᴼ / 0-90ᴼ) This is plain text, not a code :)

1AZ / EL Potentiometers limit calibration PROCEDURE  ( 0-359ᴼ /  0-90ᴼ)
2   
31. Open the code in Arduino and
4- Look for:
5
6// ************** FOR   CALIBRATION PURPOSES **************
7/*
8  Serial.print ("Az ");
9  Serial.println   (analogRead(AzPotPin));
10  Serial.print ("El ");
11  Serial.println (analogRead(ElPotPin));
12*/
13
14-   Eliminate the simbols /* and */
15- The text above should turn from gray into black   and coloured.
16
17
182. Upload the code and open the serial monitor. There you   will see a lot of numbers;
19
203. With the help of the encoders, move the antenna   to minimum values, 0ᴼ in azimuth and 0ᴼ in elevation.
21- Write down the values   for Azimuth and Elevation. (in my case it was AzMin=90, ElMin=10)
22- These are   the input values read by Arduino, not the real angles;
23
244. Move the antenna   again to maximum values,  359ᴼ in azimuth and 90ᴼ in elevation.
25- Again, write   down the values for Azimuth and Elevation. (in my case it was AzMax=1000, ElMax=992);
26
275.   Look in the code, at the beginning, for the section
28
29// ANTENNA potentiometers   CALIBRATION
30  int AzMin = 1;
31  int AzMax = 1023;
32  int ElMin = 1;
33  int   ElMax = 1023;
34
35- Here input the values you wrote down earlier, like
36  int   AzMin = 90;
37  int AzMax = 1000;
38  int ElMin = 10;
39  int ElMax = 992;
40
416.   Now it is no longer necessary to send this on serial, so you have to comment back   these lines, like this:
42/*
43  Serial.print ("Az ");
44  Serial.println (analogRead(AzPotPin));
45   Serial.print ("El ");
46  Serial.println (analogRead(ElPotPin));
47*/
48-   The text above should turn gray
49
507. Upload again the code.
51
52That's all.   Now, in the serial monitor, there should be no more numbers.

AZ / EL Potentiometers limit calibration PROCEDURE  ( 0-359ᴼ /  0-90ᴼ)
   
1. Open the code in Arduino and
- Look for:

// ************** FOR   CALIBRATION PURPOSES **************
/*
  Serial.print ("Az ");
  Serial.println   (analogRead(AzPotPin));
  Serial.print ("El ");
  Serial.println (analogRead(ElPotPin));
*/

-   Eliminate the simbols /* and */
- The text above should turn from gray into black   and coloured.


2. Upload the code and open the serial monitor. There you   will see a lot of numbers;

3. With the help of the encoders, move the antenna   to minimum values, 0ᴼ in azimuth and 0ᴼ in elevation.
- Write down the values   for Azimuth and Elevation. (in my case it was AzMin=90, ElMin=10)
- These are   the input values read by Arduino, not the real angles;

4. Move the antenna   again to maximum values,  359ᴼ in azimuth and 90ᴼ in elevation.
- Again, write   down the values for Azimuth and Elevation. (in my case it was AzMax=1000, ElMax=992);

5.   Look in the code, at the beginning, for the section

// ANTENNA potentiometers   CALIBRATION
  int AzMin = 1;
  int AzMax = 1023;
  int ElMin = 1;
  int   ElMax = 1023;

- Here input the values you wrote down earlier, like
  int   AzMin = 90;
  int AzMax = 1000;
  int ElMin = 10;
  int ElMax = 992;

6.   Now it is no longer necessary to send this on serial, so you have to comment back   these lines, like this:
/*
  Serial.print ("Az ");
  Serial.println (analogRead(AzPotPin));
   Serial.print ("El ");
  Serial.println (analogRead(ElPotPin));
*/
-   The text above should turn gray

7. Upload again the code.

That's all.   Now, in the serial monitor, there should be no more numbers.

Motor calibration procedure

arduino

This procedure sets the parameters for the Antenna Speed-Up / Slow-Down Zone. This is plain text, not a code :)

1Motor Calibration Procedure For Soft-Start / Soft-Stop feature.
2This   procedure sets the parameters for the Antenna Speed-Up / Slow-Down and the Dead-Zone.
3You   basically set how fast and how slow you want the antenna to start and to stop. You   also set much the target can move, before the antenna will adjust again.
4It’s   not strictly necessary, only if you don’t like the default settings.
5Make sure   you first apply the Potentiometer Calibration Procedure !!! That one is strictly   necessary.
6Look at the power diagram for a better understanding.
7
8***For   Azimuth movement***
9-As the antenna starts to move towards the target, is picking   up speed, reaching full power after <Amax> degrees difference. 
10-As the antenna   closes in to the target, below <Amax> degrees difference, it starts to slow down.   <Amax> should be higher for heavier antennas.
11-The power starts to decrease from   <PwAzMax> to <PwAzMin> until the angle difference becomes zero.
12  <PwAzMax> (in   percents %) should be 100 for full speed. If you ever think your antenna rotates   too fast, you can set a smaller <PwAzMax>.
13  <PwAzMin> (in percents %) is the   minimum power for which your motor doesn’t stall and can start under load. The power   output never falls below this value.
14-Once the antenna reaches the target position   (zero degrees error), it stops and doesn’t move again until the target travels more   than <AzErr> degrees.
15  This is a dead zone, to prevent continuously shaking   the antenna for the smallest target movement, or potentiometer position jitter.
16   The smaller the <AzErr>, the more precise tracking, the more frequent shacking   of the motors.
17
18***For Elevation movement***
19Exactly as for the Azimuth.
20
21Look   at the beginning of the code for this section. Here you can input your  desired   values.
22
23/**************THIS IS WHERE YOU REALY TWEAK THE ANTENNA MOVEMENT************/
24...
25
26//   Allowed error for which antennna won't move.
27  int AzErr = 8;
28  int ElErr   = 4;
29
30// Angle difference where soft stop begins
31  int Amax = 25;        //azimuth
32   int Emax = 15;        //elevation
33
34// min and max power for motors, percents;
35   int PwAzMin = 30;     //minimum power for which the motor doesn't stall and starts   under load
36  int PwAzMax = 100;    //full power for the fastest speed
37  int   PwElMin = 30;
38  int PwElMax = 100;
39/****************************************************************************/

Motor Calibration Procedure For Soft-Start / Soft-Stop feature.
This   procedure sets the parameters for the Antenna Speed-Up / Slow-Down and the Dead-Zone.
You   basically set how fast and how slow you want the antenna to start and to stop. You   also set much the target can move, before the antenna will adjust again.
It’s   not strictly necessary, only if you don’t like the default settings.
Make sure   you first apply the Potentiometer Calibration Procedure !!! That one is strictly   necessary.
Look at the power diagram for a better understanding.

***For   Azimuth movement***
-As the antenna starts to move towards the target, is picking   up speed, reaching full power after <Amax> degrees difference. 
-As the antenna   closes in to the target, below <Amax> degrees difference, it starts to slow down.   <Amax> should be higher for heavier antennas.
-The power starts to decrease from   <PwAzMax> to <PwAzMin> until the angle difference becomes zero.
  <PwAzMax> (in   percents %) should be 100 for full speed. If you ever think your antenna rotates   too fast, you can set a smaller <PwAzMax>.
  <PwAzMin> (in percents %) is the   minimum power for which your motor doesn’t stall and can start under load. The power   output never falls below this value.
-Once the antenna reaches the target position   (zero degrees error), it stops and doesn’t move again until the target travels more   than <AzErr> degrees.
  This is a dead zone, to prevent continuously shaking   the antenna for the smallest target movement, or potentiometer position jitter.
   The smaller the <AzErr>, the more precise tracking, the more frequent shacking   of the motors.

***For Elevation movement***
Exactly as for the Azimuth.

Look   at the beginning of the code for this section. Here you can input your  desired   values.

/**************THIS IS WHERE YOU REALY TWEAK THE ANTENNA MOVEMENT************/
...

//   Allowed error for which antennna won't move.
  int AzErr = 8;
  int ElErr   = 4;

// Angle difference where soft stop begins
  int Amax = 25;        //azimuth
   int Emax = 15;        //elevation

// min and max power for motors, percents;
   int PwAzMin = 30;     //minimum power for which the motor doesn't stall and starts   under load
  int PwAzMax = 100;    //full power for the fastest speed
  int   PwElMin = 30;
  int PwElMax = 100;
/****************************************************************************/

ant-rot-DC-aug2022

arduino

This code is for DC motors, with soft start/stop PWM output. Use electric diagram for DC motors.

1/*  AZ/EL Antenna Rotator controller for Arduino - DC motors - PWM output
2   *  =====================================================================
3 *  Uses   EasyComm protocol for computer - Tracking Software
4 *  Manual command by means   of two rotary encoders AZ - EL
5 *  
6 *  Viorel Racoviteannu
7 *  https://www.youtube.com/channel/UCiRLZX0bV9rS04BGAyUf-fA
8   *  https://racov.ro
9 *  YO3RAK@gmail.com
10 *  
11 * I cannot take any responsibility   for missuse of this code
12 * or any kind of damage it may occur from using this   code.
13 * 
14 * dec 2020 v2 - improved serial comm stability
15 * jan 2021 -   improved near target dead-zone, for which antenna won't move
16 * apr 2021 - improved   serial comm stability
17 * jun 2021 - error proportional power for tracking movement.   Real Soft-Stop
18 * aug 2021 - faster USB update, cold switching Az/El direction,   small optimizations in the code
19 * nov 2021 - cracked the secret of Soft-Start.   It wasn't hard. There you have it
20 * aug 2022 - improved EL encoder functionality,   electric diagram modified - encoders connections
21 */
22 
23#include <Wire.h>   // Library for I2C communication
24#include <LiquidCrystal_I2C.h> // https://www.arduinolibraries.info/libraries/liquid-crystal-i2-c   (Library for LCD)
25// Wiring: SDA pin is connected to A4 and SCL pin to A5.
26//   Connect to LCD via I2C, default address 0x27 (A0-A2 not jumpered)
27LiquidCrystal_I2C   lcd(0x27, 16, 2); // address, chars, rows.
28
29// declaring custom symbol for   up/down arrow
30 byte DownArrow[8] = {
31  B00000,
32  B00100,
33  B00100,
34   B00100,
35  B10101,
36  B01110,
37  B00100,
38  B00000
39};
40 byte UpArrow[8]   = {
41  B00000,
42  B00100,
43  B01110,
44  B10101,
45  B00100,
46  B00100,
47   B00100,
48  B00000
49};
50
51/***********************************THIS IS WHERE   YOU REALY TWEAK THE ANTENNA MOVEMENT***************/
52// ANTENNA potentiometers   CALIBRATION
53  int AzMin = 1;         //begining of the potentiometer
54  int   AzMax = 1023;      //end of the potentiometer 
55  int ElMin = 1;
56  int ElMax   = 1023;
57
58// Allowed error for which antennna won't move
59  int AzErr = 8;
60   int ElErr = 4;
61
62// Angle difference where soft stop begins
63  int Amax   = 25;        //azimuth
64  int Emax = 15;        //elevation
65
66// min and   max power for motors, percents;
67  int PwAzMin = 30;     //minimum power for which   the motor doesn't stall and starts under load
68  int PwAzMax = 100;    //full   power for the fastest speed
69  int PwElMin = 30;
70  int PwElMax = 100;
71
72/***************************************************************************************************/
73
74   enum PinAssignments {
75  AzPotPin = A0,        // input pin for the azim. potentiometer
76   ElPotPin = A1,        // input pin for the elev. potentiometer    
77  AzEncoderPinA   = 2,    // Az encoder right
78  AzEncoderPinB = 4,    // Az encoder left
79  AzClearButton   = 5,    // Az encoder push
80  ElEncoderPinA = 3,    // El encoder right
81  ElEncoderPinB   = 6,    // El encoder left
82  ElClearButton = 7,    // El encoder push
83  ElPWMPin   = 9,         // out pin for elevation rotation PWM command
84  AzPWMPin = 10,        //   out pin for azimuth PWM command
85  AzRotPin = 11,        // out pin for Az rotation   direction
86  ElRotPin = 12,        // out pin for El rotation direction
87  };
88   
89// Az encoder variables
90  int AzEncBut = 1;                   // variable   to toggle with encoder push button
91  volatile boolean AzEncRot;          // if   rotation occured
92  volatile boolean AzEncUp;           // direction of rotation
93   
94// El encoder variables
95  int ElEncBut = 1;
96  volatile boolean ElEncRot;
97   volatile boolean ElEncUp;
98  
99// movement variables
100  int TruAzim = 0;       // calculated real azimuth value
101  int ComAzim = 0;      // commanded azimuth   value
102  int TruElev = 0;      // calculated real elevation value
103  int ComElev   = 0;      // commanded elevation value
104  int OldTruAzim = 0;   // to store previous   azimuth value
105  int OldComAzim = 0;
106  int OldTruElev = 0;   // to store previous   elevation value
107  int OldComElev = 0;
108  int StaAzim = 0;      // Start Azimuth   angle for motor Soft-Start
109  int StaElev = 0;      // Start Elevation angle for   motor Soft-Start
110  int PwAzStop = 0;     // calculated PWM (percent) for soft-stop
111   int PwAzStar = 0;     // calculated PWM (percent) for soft-start
112  int PwElStop   = 0;     // calculated PWM (percent) for soft-stop
113  int PwElStar = 0;     //   calculated PWM (percent) for soft-start
114  int PwAz = 0;         //calculated   power to be transmitted to motor (percents);
115  int PwEl = 0;
116  char AzDir;            // symbol for azim rot display
117  char ElDir;           // symbol for   elev. rot display
118  unsigned long NowTime;         // store the current millis()   for timing purposes
119    
120// flags for AZ, EL tolerances
121  bool AzStop =   false;
122  bool ElStop = false;
123  int ElUp = 1;                  // 1 - Elevation   Dn, 0 - Elevation STOP, 2 - Elevation Up
124  
125//averaging loop
126  const int   numReadings = 25;
127  int readIndex = 0;             // the index of the current   reading  
128  int azimuth[numReadings];      // the readings from the analog input
129   int elevation[numReadings];
130  int totalAz = 0;               // the running   total
131  int totalEl = 0;
132
133// variables for serial comm
134  String Azimuth   = "";
135  String Elevation = "";
136  String ComputerRead;
137  String ComputerWrite;
138   bool AZser = false;
139  bool ELser = false;
140  bool ANTser = false;
141
142/***************   END VARIABLE DECLARATION  ************/
143
144void setup() {
145  Serial.begin(9600);
146   Serial.setTimeout(50);           // miliseconds to wait for USB sata. Default   1000
147// Initiate the LCD:
148//  lcd.begin(16,2);               //select this   one if the arrows are not displayed correctly
149  lcd.init();
150  lcd.backlight();
151
152//   write on display name and version
153  lcd.setCursor(0, 0);           // Set the   cursor on the first column first row.(counting starts at 0!)
154  lcd.print("EasyCom   AntRotor"); // display "..."
155  lcd.setCursor(0, 1);           // Set the cursor   on the first column the second row
156  lcd.print("*Racov* Aug.2022");
157
158//creating   custom symbol for up/dwn arrow
159  lcd.createChar(1, DownArrow);
160  lcd.createChar(2,   UpArrow);
161  
162// pin declaration
163  pinMode(AzRotPin, OUTPUT);       //declaring   azim. rotation direction Pin as OUTPUT
164  pinMode(AzPWMPin, OUTPUT);       //declaring   azimuth PWM command Pin as OUTPUT
165  pinMode(ElRotPin, OUTPUT);       //declaring   elev. rotation direction Pin as OUTPUT
166  pinMode(ElPWMPin, OUTPUT);
167  pinMode(AzPotPin,   INPUT);
168  pinMode(ElPotPin, INPUT);
169  pinMode(AzEncoderPinA, INPUT);
170  pinMode(AzEncoderPinB,   INPUT);
171  pinMode(AzClearButton, INPUT);
172  pinMode(ElEncoderPinA, INPUT);
173   pinMode(ElEncoderPinB, INPUT);
174
175// Interrupt Service Routine for Az and   El encoder
176  attachInterrupt(0, doAzEnc, CHANGE);                               //   Az encoder
177  attachInterrupt(1, doElEnc, CHANGE);                               //   El Encoder
178
179/* initialization of the averaging loop
180   this is to set Az/El-command   the same value as real, not to jerk the antenna at start-up */
181  TruAzim = (map(analogRead(AzPotPin),   AzMin, AzMax, 0, 359));       // transforms potentiometer voltage into azimuth angle
182   TruElev = (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));        // transforms   potentiometer voltage into elevation angle
183
184  for (int thisReading = 0; thisReading   < numReadings; thisReading++) {
185    azimuth[thisReading] = TruAzim;
186    elevation[thisReading]   = TruElev;
187  }
188  totalAz = TruAzim * numReadings;
189  totalEl = TruElev *   numReadings;
190
191/* keep command values in range  */
192  ComAzim = constrain(TruAzim,   0, 359);
193  ComElev = constrain(TruElev, 0, 90);
194  OldTruAzim = TruAzim;
195   OldComAzim = ComAzim;
196  OldTruElev = TruElev;
197  OldComElev = TruElev;
198
199   delay(1500);                     // keep for 1.5 seconds
200// display Azim. and   Elev. values
201  lcd.setCursor(0, 0);
202  lcd.print("Azm.---" + String(char(223))   + "=Cd.---" + String(char(223)));  // char(223) is degree symbol
203  lcd.setCursor(0,   1); 
204  lcd.print("Elv. --" + String(char(223)) + "=Cd. --" + String(char(223)));
205   DisplValue(TruAzim, 4,0);
206  DisplValue(ComAzim,12,0);
207  DisplValue(TruElev,   4,1);
208  DisplValue(ComElev,12,1);
209}
210// end SETUP
211
212void loop() {
213/**************   FYI, this loop repeats 500 times per second !!! **************/
214// AZIMUTH/ELEVATION   AVERAGING LOOP
215  // subtract the oldest value
216  totalAz = totalAz - azimuth[readIndex];
217   totalEl = totalEl - elevation[readIndex];
218  // read from the sensor:
219  azimuth[readIndex]   = (map(analogRead(AzPotPin), AzMin, AzMax, 0, 359));
220  elevation[readIndex] =   (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));
221  // add the reading to the   total:
222  totalAz = totalAz + azimuth[readIndex];
223  totalEl = totalEl + elevation[readIndex];
224   // do the average
225  TruAzim = totalAz / numReadings;
226  TruElev = totalEl   / numReadings;
227/*  keep values in range
228  TruAzim = constrain(TruAzim, 0,   359);
229  TruElev = constrain(TruElev, 0, 90); */
230  // advance to the next position   in the array
231  // if we're at the end of the array, wrap around to the beginning:
232   readIndex = (readIndex + 1) % numReadings;
233
234// read the command from encoder
235   ReadAzimEncoder();
236  ReadElevEncoder();
237  
238  if (Serial.available())   {SerComm();}          // read USB data
239
240// update antenna position display   only if value change
241  if ((millis() - NowTime) > 300){              //every   0.3 seconds, not to flicker the display
242    if (OldTruAzim!=TruAzim) {
243      DisplValue(TruAzim,4,0);
244       OldTruAzim = TruAzim;
245    }
246    if (OldTruElev!=TruElev) {
247      DisplValue(TruElev,4,1);
248       OldTruElev = TruElev;
249    }
250    NowTime = millis();
251  }
252
253//   update target position display only if value change
254  if (OldComAzim != ComAzim)   {
255    DisplValue(ComAzim,12,0);
256    OldComAzim = ComAzim;
257  }
258  if (OldComElev   != ComElev) {
259    DisplValue(ComElev,12,1);
260    OldComElev = ComElev;
261   }
262
263// this is to rotate in azimuth
264  if (TruAzim == ComAzim) {                   //   if equal, stop moving
265    AzStop = true;
266    analogWrite(AzPWMPin, 0);                 //   Az motor power = 0
267    StaAzim = TruAzim;                        // this will   be the start azimuth for soft-start
268    lcd.setCursor(8, 0);
269    lcd.print("=");
270   }
271    else if ((abs(TruAzim - ComAzim)<=AzErr)&&(AzStop == false)) {  // if   in tolerance, but it wasn't an equal, rotate
272      AzimRotate();}
273    else   if (abs(TruAzim - ComAzim)>AzErr){   // if target is off tolerance
274      AzStop   = false;                         // it's not equal
275      AzimRotate();                           //   rotate
276    }
277
278// this is to rotate in elevation
279  if (TruElev == ComElev)   {                   // if equal, stop moving
280    ElStop = true;
281    analogWrite(ElPWMPin,   0);                 // El motor power = 0
282    StaElev = TruElev;                        //   this will be the start elevation for soft-start
283    lcd.setCursor(8, 1);
284     lcd.print("=");
285    ElUp = 0;                                 // flag for   elevation STOP
286  }
287  else if ((abs(TruElev - ComElev)<=ElErr)&&(ElStop ==   false)) {  // if in tolerance, but it wasn't an equal, rotate
288    ElevRotate();}
289   else if (abs(TruElev - ComElev)>ElErr){     // if target is off tolerance
290     ElStop = false;                           // it's not equal
291    ElevRotate();                              // rotate
292  }
293  
294  // this is to interpret   Az encoder x10 multiplication
295  while (AzEncBut == 10) {                    //   while toggled to x10
296    analogWrite(AzPWMPin, 0);                 // STOP antenna   rotation
297    StaAzim = TruAzim;                        // this will be the start   azimuth for soft-start
298    analogWrite(ElPWMPin, 0);
299    lcd.setCursor(8,   0);
300    lcd.print("*");
301    ReadAzimEncoder();
302    if (OldComAzim !=   ComAzim){               // update display only if numbers change
303      DisplValue(ComAzim,   12, 0);
304      OldComAzim = ComAzim;
305    }
306    delay (100);
307  }
308}   // end main LOOP
309
310//____________________________________________________
311//   ___________procedures definitions__________________
312
313void DisplValue(int x,   int y, int z) {
314  char displayString[7] = "";
315  sprintf(displayString, "%3d",   x);           // outputs a fixed lenght number (3 integer)
316  lcd.setCursor(y,   z);                        // for leading zeros '007' use "%03d"
317  lcd.print(displayString);
318   
319// ************** FOR CALIBRATION PURPOSES **************
320/*
321  Serial.print   ("Az ");
322  Serial.println (analogRead(AzPotPin));
323  Serial.print ("El ");
324   Serial.println (analogRead(ElPotPin));
325*/
326}  // end DisplValue()
327
328void   ReadAzimEncoder() {
329  if (digitalRead(AzClearButton) == LOW )  {      // if encoder   switch depressed
330    delay (250);                                  // debounce   switch
331    lcd.setCursor(0, 0);                          // refresh all the writings   on the screen
332    lcd.print("Azm.---" + String(char(223)) + "=Cd.---" + String(char(223)));
333     lcd.setCursor(0, 1); 
334    lcd.print("Elv. --" + String(char(223)) + "=Cd.   --" + String(char(223)));
335    DisplValue(TruAzim, 4,0);
336    DisplValue(ComAzim,12,0);
337     DisplValue(TruElev, 4,1);
338    DisplValue(ComElev,12,1);
339    if (AzEncBut   == 1){
340      AzEncBut = 10;                              // increment by 10 degrees
341       ComAzim = int(ComAzim/10)*10;               // ComAzim in 10deg. steps 
342     }
343    else
344      AzEncBut = 1;
345  }
346
347  if (AzEncRot){
348    delay(20);                                     // debouncing
349    if (AzEncUp)
350      ComAzim   += AzEncBut;
351    else
352      ComAzim -= AzEncBut;
353    ComAzim = ((ComAzim   + 360) % 360);            // Az Cmd between 0 and 359 deg continuous
354    AzEncRot   = false;
355  }
356} //end ReadAzimEncoder()
357
358void ReadElevEncoder() {
359   if (digitalRead(ElClearButton) == LOW )  {      // set Park Position Command Az/El
360     delay(250);                                   // debounce switch
361    ComAzim   = 260;
362    ComElev = 0;
363  }
364
365  if (ElEncRot){
366    delay(20);                                    //   debouncing
367    if (ElEncUp)
368      ComElev ++;
369    else
370      ComElev   --;
371    ComElev = constrain(ComElev, 0, 90);          // keep El Cmd value in   range
372    ElEncRot = false;
373  }
374}  // end of ReadElevEncoder()
375
376//   Interrupt Service Routine for a change to encoder pin A and B
377void doAzEnc ()
378{
379   if (digitalRead (AzEncoderPinA))
380    AzEncUp = digitalRead (AzEncoderPinB);
381   else
382    AzEncUp = !digitalRead (AzEncoderPinB);
383  AzEncRot = true;
384}   // end of doAzEnc
385
386void doElEnc ()
387{
388  if (digitalRead (ElEncoderPinA))
389     ElEncUp = digitalRead (ElEncoderPinB);
390  else
391    ElEncUp = !digitalRead   (ElEncoderPinB);
392    ElEncRot = true;
393}  // end of doElEnc
394
395void AzimRotate()   {
396    if (ComAzim > TruAzim) {                          // this to determine   direction of rotation
397// cold switching - stop motor before changing direction   - to protect mechanic and electric parts
398        if (AzDir == char(127)) {                     //   if previously rotating in the oposite direction
399          analogWrite(AzPWMPin,   0);                   // STOP the motor
400          StaAzim = TruAzim;                          //   this will be the start azimuth for soft-start
401          delay(200);                                 //   pre-switch delay
402          digitalWrite(AzRotPin, LOW);                // deactivate   rotation pin - rotate right
403          delay(200);                                 //   post-switch delay
404        }
405        else {                                        //   same directin, no Stop, no delay
406          digitalWrite(AzRotPin, LOW);                //   deactivate rotation pin - rotate right
407        }
408          AzDir = char(126);                           // "->"
409    }
410      else {
411        if (AzDir   == char(126)) {                     // if previously rotating in the oposite direction
412           analogWrite(AzPWMPin, 0);                   // STOP the motor
413          StaAzim   = TruAzim;                          // this will be the start azimuth for soft-start
414           delay(200);                                 // pre-switch delay
415          digitalWrite(AzRotPin,   HIGH);               // activate rotation pin - rotate left
416          delay(200);                                  // post-switch delay
417        }
418        else   {                                        // same directin, no Stop, no delay
419           digitalWrite(AzRotPin, HIGH);               // activate rotation pin -   rotate left
420        }
421        AzDir = char(127);                            //   "<-"
422      }
423    lcd.setCursor(8, 0);
424    lcd.print(String(AzDir));
425   // this activates azim PWM pin proportional with angle error (calculated in percents   %)
426    PwAzStop = PwAzMin + round((abs(ComAzim-TruAzim))*(PwAzMax-PwAzMin)/Amax);    //formula which outputs a power proportional with angle difference for Soft-Stop
427     PwAzStar = PwAzMin + round((abs(StaAzim-TruAzim))*(PwAzMax-PwAzMin)/Amax);   //formula   which outputs a power proportional with angle difference for Soft-Start
428    if   (PwAzStar > PwAzStop){
429         PwAz = PwAzStop;                             //choose   whichever value is smallest
430      }
431      else {PwAz = PwAzStar;}
432    if   (PwAz > PwAzMax) {PwAz = PwAzMax;}
433    analogWrite(AzPWMPin, round(2.55*PwAz));           // activate Azim drive PWM pin 
434}  // end AzimRotate()
435
436void   ElevRotate() {
437// this to determine direction of rotation
438    if (ComElev   > TruElev) {
439      if (ElUp == 1) {                                // if previously   rotating in the oposite direction
440        analogWrite(ElPWMPin, 0);                     //   STOP the motor
441        StaElev = TruElev;                            // this   will be the start elevation for soft-start
442        delay(200);                                   //   pre-switch delay
443        digitalWrite(ElRotPin, LOW);                  // deactivate   rotation pin - rotate UP
444        delay(200);                                   //   post-switch delay
445      }
446      else {                                          //   same directin, no Stop, no delay
447        digitalWrite(ElRotPin, LOW);                  //   deactivate rotation pin - rotate UP
448      }
449      lcd.setCursor(8, 1);
450       lcd.write(2);                                   // arrow up
451      ElUp   = 2;                                       // flag for elevation UP
452    }
453      else {
454      if (ElUp == 2) {                                // if previously   rotating in the oposite direction
455        analogWrite(ElPWMPin, 0);                     //   STOP the motor
456        StaElev = TruElev;                            // this   will be the start elevation for soft-start
457        delay(200);                                   //   pre-switch delay
458        digitalWrite(ElRotPin, HIGH);                 // deactivate   rotation pin - rotate UP
459        delay(200);                                   //   post-switch delay
460      }
461      else {                                          //   same directin, no Stop, no delay
462        digitalWrite(ElRotPin, HIGH);                 //   deactivate rotation pin - rotate UP
463      }
464        lcd.setCursor(8, 1);
465         lcd.write(1);                                 // arrow down
466        ElUp   = 1;                                     // flag for elevation DN
467    }
468 //   this activates azim PWM pin proportional with angle error (calculated in percents   %)
469    PwElStop = PwElMin + round((abs(ComElev-TruElev))*(PwElMax-PwElMin)/Emax);    //formula which outputs a power proportional with angle difference for Soft-Stop
470     PwElStar = PwElMin + round((abs(StaElev-TruElev))*(PwElMax-PwElMin)/Emax);   //formula   which outputs a power proportional with angle difference for Soft-Start
471    if   (PwElStar > PwElStop){
472         PwEl = PwElStop;                             //choose   whichever value is smallest
473      }
474      else {PwEl = PwElStar;}
475    if   (PwEl > PwElMax) {PwEl = PwElMax;}
476    analogWrite(ElPWMPin, round(2.55*PwEl));           // activate Elev drive PWM pin
477}  // end ElevRotate()
478
479void SerComm()   {
480  // initialize readings
481  ComputerRead = "";
482  Azimuth = "";
483   Elevation = "";
484
485  while(Serial.available()) {
486    ComputerRead= Serial.readString();   // read the incoming data as string
487//    Serial.println(ComputerRead);     //   echo the reception for testing purposes
488  }
489  
490// looking for command <AZxxx.x>
491     for (int i = 0; i <= ComputerRead.length(); i++) {
492     if ((ComputerRead.charAt(i)   == 'A')&&(ComputerRead.charAt(i+1) == 'Z')){ // if read AZ
493      for (int j =   i+2; j <= ComputerRead.length(); j++) {
494        if (isDigit(ComputerRead.charAt(j)))   {                                // if the character is number
495          Azimuth   = Azimuth + ComputerRead.charAt(j);
496        }
497        else {break;}
498      }
499      }
500    }
501    
502// looking for command <ELxxx.x>
503    for (int i =   0; i <= (ComputerRead.length()-2); i++) {
504      if ((ComputerRead.charAt(i) ==   'E')&&(ComputerRead.charAt(i+1) == 'L')){ // if read EL
505        if ((ComputerRead.charAt(i+2))   == '-') {
506          ComElev = 0;                  // if elevation negative
507           break;
508        }
509        for (int j = i+2; j <= ComputerRead.length();   j++) {
510          if (isDigit(ComputerRead.charAt(j))) {                               //   if the character is number
511            Elevation = Elevation + ComputerRead.charAt(j);
512           }
513          else {break;}
514        }
515      }
516    }
517    
518//   if <AZxx> received
519    if (Azimuth != ""){
520      ComAzim = Azimuth.toInt();
521       ComAzim = ComAzim%360;          // keeping values between limits(for trackers   with more than 360 deg. rotation)
522      }
523
524// if <ELxx> received
525    if   (Elevation != ""){
526      ComElev = Elevation.toInt();
527      if (ComElev>180)   { ComElev = 0;}
528      if (ComElev>90) {               //if received more than   90deg. (for trackers with 180deg. elevation)
529        ComElev = 180-ComElev;        //keep   below 90deg.
530        ComAzim = (ComAzim+180)%360;  //and rotate the antenna on   the back
531      }
532    }
533
534// looking for <AZ EL> interogation for antenna   position
535  for (int i = 0; i <= (ComputerRead.length()-4); i++) {
536    if ((ComputerRead.charAt(i)   == 'A')&&(ComputerRead.charAt(i+1) == 'Z')&&(ComputerRead.charAt(i+3) == 'E')&&(ComputerRead.charAt(i+4)   == 'L')){
537    // send back the antenna position <+xxx.x xx.x>
538      ComputerWrite   = "+"+String(TruAzim)+".0 "+String(TruElev)+".0";
539    //ComputerWrite =   "AZ"+String(TruAzim)+".0 EL"+String(TruElev)+".0"; //that's for Gpredict and   HamLib
540      Serial.println(ComputerWrite);
541    }
542  }
543}  // end SerComm()
544

/*  AZ/EL Antenna Rotator controller for Arduino - DC motors - PWM output
   *  =====================================================================
 *  Uses   EasyComm protocol for computer - Tracking Software
 *  Manual command by means   of two rotary encoders AZ - EL
 *  
 *  Viorel Racoviteannu
 *  https://www.youtube.com/channel/UCiRLZX0bV9rS04BGAyUf-fA
   *  https://racov.ro
 *  YO3RAK@gmail.com
 *  
 * I cannot take any responsibility   for missuse of this code
 * or any kind of damage it may occur from using this   code.
 * 
 * dec 2020 v2 - improved serial comm stability
 * jan 2021 -   improved near target dead-zone, for which antenna won't move
 * apr 2021 - improved   serial comm stability
 * jun 2021 - error proportional power for tracking movement.   Real Soft-Stop
 * aug 2021 - faster USB update, cold switching Az/El direction,   small optimizations in the code
 * nov 2021 - cracked the secret of Soft-Start.   It wasn't hard. There you have it
 * aug 2022 - improved EL encoder functionality,   electric diagram modified - encoders connections
 */
 
#include <Wire.h>   // Library for I2C communication
#include <LiquidCrystal_I2C.h> // https://www.arduinolibraries.info/libraries/liquid-crystal-i2-c   (Library for LCD)
// Wiring: SDA pin is connected to A4 and SCL pin to A5.
//   Connect to LCD via I2C, default address 0x27 (A0-A2 not jumpered)
LiquidCrystal_I2C   lcd(0x27, 16, 2); // address, chars, rows.

// declaring custom symbol for   up/down arrow
 byte DownArrow[8] = {
  B00000,
  B00100,
  B00100,
   B00100,
  B10101,
  B01110,
  B00100,
  B00000
};
 byte UpArrow[8]   = {
  B00000,
  B00100,
  B01110,
  B10101,
  B00100,
  B00100,
   B00100,
  B00000
};

/***********************************THIS IS WHERE   YOU REALY TWEAK THE ANTENNA MOVEMENT***************/
// ANTENNA potentiometers   CALIBRATION
  int AzMin = 1;         //begining of the potentiometer
  int   AzMax = 1023;      //end of the potentiometer 
  int ElMin = 1;
  int ElMax   = 1023;

// Allowed error for which antennna won't move
  int AzErr = 8;
   int ElErr = 4;

// Angle difference where soft stop begins
  int Amax   = 25;        //azimuth
  int Emax = 15;        //elevation

// min and   max power for motors, percents;
  int PwAzMin = 30;     //minimum power for which   the motor doesn't stall and starts under load
  int PwAzMax = 100;    //full   power for the fastest speed
  int PwElMin = 30;
  int PwElMax = 100;

/***************************************************************************************************/

   enum PinAssignments {
  AzPotPin = A0,        // input pin for the azim. potentiometer
   ElPotPin = A1,        // input pin for the elev. potentiometer    
  AzEncoderPinA   = 2,    // Az encoder right
  AzEncoderPinB = 4,    // Az encoder left
  AzClearButton   = 5,    // Az encoder push
  ElEncoderPinA = 3,    // El encoder right
  ElEncoderPinB   = 6,    // El encoder left
  ElClearButton = 7,    // El encoder push
  ElPWMPin   = 9,         // out pin for elevation rotation PWM command
  AzPWMPin = 10,        //   out pin for azimuth PWM command
  AzRotPin = 11,        // out pin for Az rotation   direction
  ElRotPin = 12,        // out pin for El rotation direction
  };
   
// Az encoder variables
  int AzEncBut = 1;                   // variable   to toggle with encoder push button
  volatile boolean AzEncRot;          // if   rotation occured
  volatile boolean AzEncUp;           // direction of rotation
   
// El encoder variables
  int ElEncBut = 1;
  volatile boolean ElEncRot;
   volatile boolean ElEncUp;
  
// movement variables
  int TruAzim = 0;       // calculated real azimuth value
  int ComAzim = 0;      // commanded azimuth   value
  int TruElev = 0;      // calculated real elevation value
  int ComElev   = 0;      // commanded elevation value
  int OldTruAzim = 0;   // to store previous   azimuth value
  int OldComAzim = 0;
  int OldTruElev = 0;   // to store previous   elevation value
  int OldComElev = 0;
  int StaAzim = 0;      // Start Azimuth   angle for motor Soft-Start
  int StaElev = 0;      // Start Elevation angle for   motor Soft-Start
  int PwAzStop = 0;     // calculated PWM (percent) for soft-stop
   int PwAzStar = 0;     // calculated PWM (percent) for soft-start
  int PwElStop   = 0;     // calculated PWM (percent) for soft-stop
  int PwElStar = 0;     //   calculated PWM (percent) for soft-start
  int PwAz = 0;         //calculated   power to be transmitted to motor (percents);
  int PwEl = 0;
  char AzDir;            // symbol for azim rot display
  char ElDir;           // symbol for   elev. rot display
  unsigned long NowTime;         // store the current millis()   for timing purposes
    
// flags for AZ, EL tolerances
  bool AzStop =   false;
  bool ElStop = false;
  int ElUp = 1;                  // 1 - Elevation   Dn, 0 - Elevation STOP, 2 - Elevation Up
  
//averaging loop
  const int   numReadings = 25;
  int readIndex = 0;             // the index of the current   reading  
  int azimuth[numReadings];      // the readings from the analog input
   int elevation[numReadings];
  int totalAz = 0;               // the running   total
  int totalEl = 0;

// variables for serial comm
  String Azimuth   = "";
  String Elevation = "";
  String ComputerRead;
  String ComputerWrite;
   bool AZser = false;
  bool ELser = false;
  bool ANTser = false;

/***************   END VARIABLE DECLARATION  ************/

void setup() {
  Serial.begin(9600);
   Serial.setTimeout(50);           // miliseconds to wait for USB sata. Default   1000
// Initiate the LCD:
//  lcd.begin(16,2);               //select this   one if the arrows are not displayed correctly
  lcd.init();
  lcd.backlight();

//   write on display name and version
  lcd.setCursor(0, 0);           // Set the   cursor on the first column first row.(counting starts at 0!)
  lcd.print("EasyCom   AntRotor"); // display "..."
  lcd.setCursor(0, 1);           // Set the cursor   on the first column the second row
  lcd.print("*Racov* Aug.2022");

//creating   custom symbol for up/dwn arrow
  lcd.createChar(1, DownArrow);
  lcd.createChar(2,   UpArrow);
  
// pin declaration
  pinMode(AzRotPin, OUTPUT);       //declaring   azim. rotation direction Pin as OUTPUT
  pinMode(AzPWMPin, OUTPUT);       //declaring   azimuth PWM command Pin as OUTPUT
  pinMode(ElRotPin, OUTPUT);       //declaring   elev. rotation direction Pin as OUTPUT
  pinMode(ElPWMPin, OUTPUT);
  pinMode(AzPotPin,   INPUT);
  pinMode(ElPotPin, INPUT);
  pinMode(AzEncoderPinA, INPUT);
  pinMode(AzEncoderPinB,   INPUT);
  pinMode(AzClearButton, INPUT);
  pinMode(ElEncoderPinA, INPUT);
   pinMode(ElEncoderPinB, INPUT);

// Interrupt Service Routine for Az and   El encoder
  attachInterrupt(0, doAzEnc, CHANGE);                               //   Az encoder
  attachInterrupt(1, doElEnc, CHANGE);                               //   El Encoder

/* initialization of the averaging loop
   this is to set Az/El-command   the same value as real, not to jerk the antenna at start-up */
  TruAzim = (map(analogRead(AzPotPin),   AzMin, AzMax, 0, 359));       // transforms potentiometer voltage into azimuth angle
   TruElev = (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));        // transforms   potentiometer voltage into elevation angle

  for (int thisReading = 0; thisReading   < numReadings; thisReading++) {
    azimuth[thisReading] = TruAzim;
    elevation[thisReading]   = TruElev;
  }
  totalAz = TruAzim * numReadings;
  totalEl = TruElev *   numReadings;

/* keep command values in range  */
  ComAzim = constrain(TruAzim,   0, 359);
  ComElev = constrain(TruElev, 0, 90);
  OldTruAzim = TruAzim;
   OldComAzim = ComAzim;
  OldTruElev = TruElev;
  OldComElev = TruElev;

   delay(1500);                     // keep for 1.5 seconds
// display Azim. and   Elev. values
  lcd.setCursor(0, 0);
  lcd.print("Azm.---" + String(char(223))   + "=Cd.---" + String(char(223)));  // char(223) is degree symbol
  lcd.setCursor(0,   1); 
  lcd.print("Elv. --" + String(char(223)) + "=Cd. --" + String(char(223)));
   DisplValue(TruAzim, 4,0);
  DisplValue(ComAzim,12,0);
  DisplValue(TruElev,   4,1);
  DisplValue(ComElev,12,1);
}
// end SETUP

void loop() {
/**************   FYI, this loop repeats 500 times per second !!! **************/
// AZIMUTH/ELEVATION   AVERAGING LOOP
  // subtract the oldest value
  totalAz = totalAz - azimuth[readIndex];
   totalEl = totalEl - elevation[readIndex];
  // read from the sensor:
  azimuth[readIndex]   = (map(analogRead(AzPotPin), AzMin, AzMax, 0, 359));
  elevation[readIndex] =   (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));
  // add the reading to the   total:
  totalAz = totalAz + azimuth[readIndex];
  totalEl = totalEl + elevation[readIndex];
   // do the average
  TruAzim = totalAz / numReadings;
  TruElev = totalEl   / numReadings;
/*  keep values in range
  TruAzim = constrain(TruAzim, 0,   359);
  TruElev = constrain(TruElev, 0, 90); */
  // advance to the next position   in the array
  // if we're at the end of the array, wrap around to the beginning:
   readIndex = (readIndex + 1) % numReadings;

// read the command from encoder
   ReadAzimEncoder();
  ReadElevEncoder();
  
  if (Serial.available())   {SerComm();}          // read USB data

// update antenna position display   only if value change
  if ((millis() - NowTime) > 300){              //every   0.3 seconds, not to flicker the display
    if (OldTruAzim!=TruAzim) {
      DisplValue(TruAzim,4,0);
       OldTruAzim = TruAzim;
    }
    if (OldTruElev!=TruElev) {
      DisplValue(TruElev,4,1);
       OldTruElev = TruElev;
    }
    NowTime = millis();
  }

//   update target position display only if value change
  if (OldComAzim != ComAzim)   {
    DisplValue(ComAzim,12,0);
    OldComAzim = ComAzim;
  }
  if (OldComElev   != ComElev) {
    DisplValue(ComElev,12,1);
    OldComElev = ComElev;
   }

// this is to rotate in azimuth
  if (TruAzim == ComAzim) {                   //   if equal, stop moving
    AzStop = true;
    analogWrite(AzPWMPin, 0);                 //   Az motor power = 0
    StaAzim = TruAzim;                        // this will   be the start azimuth for soft-start
    lcd.setCursor(8, 0);
    lcd.print("=");
   }
    else if ((abs(TruAzim - ComAzim)<=AzErr)&&(AzStop == false)) {  // if   in tolerance, but it wasn't an equal, rotate
      AzimRotate();}
    else   if (abs(TruAzim - ComAzim)>AzErr){   // if target is off tolerance
      AzStop   = false;                         // it's not equal
      AzimRotate();                           //   rotate
    }

// this is to rotate in elevation
  if (TruElev == ComElev)   {                   // if equal, stop moving
    ElStop = true;
    analogWrite(ElPWMPin,   0);                 // El motor power = 0
    StaElev = TruElev;                        //   this will be the start elevation for soft-start
    lcd.setCursor(8, 1);
     lcd.print("=");
    ElUp = 0;                                 // flag for   elevation STOP
  }
  else if ((abs(TruElev - ComElev)<=ElErr)&&(ElStop ==   false)) {  // if in tolerance, but it wasn't an equal, rotate
    ElevRotate();}
   else if (abs(TruElev - ComElev)>ElErr){     // if target is off tolerance
     ElStop = false;                           // it's not equal
    ElevRotate();                              // rotate
  }
  
  // this is to interpret   Az encoder x10 multiplication
  while (AzEncBut == 10) {                    //   while toggled to x10
    analogWrite(AzPWMPin, 0);                 // STOP antenna   rotation
    StaAzim = TruAzim;                        // this will be the start   azimuth for soft-start
    analogWrite(ElPWMPin, 0);
    lcd.setCursor(8,   0);
    lcd.print("*");
    ReadAzimEncoder();
    if (OldComAzim !=   ComAzim){               // update display only if numbers change
      DisplValue(ComAzim,   12, 0);
      OldComAzim = ComAzim;
    }
    delay (100);
  }
}   // end main LOOP

//____________________________________________________
//   ___________procedures definitions__________________

void DisplValue(int x,   int y, int z) {
  char displayString[7] = "";
  sprintf(displayString, "%3d",   x);           // outputs a fixed lenght number (3 integer)
  lcd.setCursor(y,   z);                        // for leading zeros '007' use "%03d"
  lcd.print(displayString);
   
// ************** FOR CALIBRATION PURPOSES **************
/*
  Serial.print   ("Az ");
  Serial.println (analogRead(AzPotPin));
  Serial.print ("El ");
   Serial.println (analogRead(ElPotPin));
*/
}  // end DisplValue()

void   ReadAzimEncoder() {
  if (digitalRead(AzClearButton) == LOW )  {      // if encoder   switch depressed
    delay (250);                                  // debounce   switch
    lcd.setCursor(0, 0);                          // refresh all the writings   on the screen
    lcd.print("Azm.---" + String(char(223)) + "=Cd.---" + String(char(223)));
     lcd.setCursor(0, 1); 
    lcd.print("Elv. --" + String(char(223)) + "=Cd.   --" + String(char(223)));
    DisplValue(TruAzim, 4,0);
    DisplValue(ComAzim,12,0);
     DisplValue(TruElev, 4,1);
    DisplValue(ComElev,12,1);
    if (AzEncBut   == 1){
      AzEncBut = 10;                              // increment by 10 degrees
       ComAzim = int(ComAzim/10)*10;               // ComAzim in 10deg. steps 
     }
    else
      AzEncBut = 1;
  }

  if (AzEncRot){
    delay(20);                                     // debouncing
    if (AzEncUp)
      ComAzim   += AzEncBut;
    else
      ComAzim -= AzEncBut;
    ComAzim = ((ComAzim   + 360) % 360);            // Az Cmd between 0 and 359 deg continuous
    AzEncRot   = false;
  }
} //end ReadAzimEncoder()

void ReadElevEncoder() {
   if (digitalRead(ElClearButton) == LOW )  {      // set Park Position Command Az/El
     delay(250);                                   // debounce switch
    ComAzim   = 260;
    ComElev = 0;
  }

  if (ElEncRot){
    delay(20);                                    //   debouncing
    if (ElEncUp)
      ComElev ++;
    else
      ComElev   --;
    ComElev = constrain(ComElev, 0, 90);          // keep El Cmd value in   range
    ElEncRot = false;
  }
}  // end of ReadElevEncoder()

//   Interrupt Service Routine for a change to encoder pin A and B
void doAzEnc ()
{
   if (digitalRead (AzEncoderPinA))
    AzEncUp = digitalRead (AzEncoderPinB);
   else
    AzEncUp = !digitalRead (AzEncoderPinB);
  AzEncRot = true;
}   // end of doAzEnc

void doElEnc ()
{
  if (digitalRead (ElEncoderPinA))
     ElEncUp = digitalRead (ElEncoderPinB);
  else
    ElEncUp = !digitalRead   (ElEncoderPinB);
    ElEncRot = true;
}  // end of doElEnc

void AzimRotate()   {
    if (ComAzim > TruAzim) {                          // this to determine   direction of rotation
// cold switching - stop motor before changing direction   - to protect mechanic and electric parts
        if (AzDir == char(127)) {                     //   if previously rotating in the oposite direction
          analogWrite(AzPWMPin,   0);                   // STOP the motor
          StaAzim = TruAzim;                          //   this will be the start azimuth for soft-start
          delay(200);                                 //   pre-switch delay
          digitalWrite(AzRotPin, LOW);                // deactivate   rotation pin - rotate right
          delay(200);                                 //   post-switch delay
        }
        else {                                        //   same directin, no Stop, no delay
          digitalWrite(AzRotPin, LOW);                //   deactivate rotation pin - rotate right
        }
          AzDir = char(126);                           // "->"
    }
      else {
        if (AzDir   == char(126)) {                     // if previously rotating in the oposite direction
           analogWrite(AzPWMPin, 0);                   // STOP the motor
          StaAzim   = TruAzim;                          // this will be the start azimuth for soft-start
           delay(200);                                 // pre-switch delay
          digitalWrite(AzRotPin,   HIGH);               // activate rotation pin - rotate left
          delay(200);                                  // post-switch delay
        }
        else   {                                        // same directin, no Stop, no delay
           digitalWrite(AzRotPin, HIGH);               // activate rotation pin -   rotate left
        }
        AzDir = char(127);                            //   "<-"
      }
    lcd.setCursor(8, 0);
    lcd.print(String(AzDir));
   // this activates azim PWM pin proportional with angle error (calculated in percents   %)
    PwAzStop = PwAzMin + round((abs(ComAzim-TruAzim))*(PwAzMax-PwAzMin)/Amax);    //formula which outputs a power proportional with angle difference for Soft-Stop
     PwAzStar = PwAzMin + round((abs(StaAzim-TruAzim))*(PwAzMax-PwAzMin)/Amax);   //formula   which outputs a power proportional with angle difference for Soft-Start
    if   (PwAzStar > PwAzStop){
         PwAz = PwAzStop;                             //choose   whichever value is smallest
      }
      else {PwAz = PwAzStar;}
    if   (PwAz > PwAzMax) {PwAz = PwAzMax;}
    analogWrite(AzPWMPin, round(2.55*PwAz));           // activate Azim drive PWM pin 
}  // end AzimRotate()

void   ElevRotate() {
// this to determine direction of rotation
    if (ComElev   > TruElev) {
      if (ElUp == 1) {                                // if previously   rotating in the oposite direction
        analogWrite(ElPWMPin, 0);                     //   STOP the motor
        StaElev = TruElev;                            // this   will be the start elevation for soft-start
        delay(200);                                   //   pre-switch delay
        digitalWrite(ElRotPin, LOW);                  // deactivate   rotation pin - rotate UP
        delay(200);                                   //   post-switch delay
      }
      else {                                          //   same directin, no Stop, no delay
        digitalWrite(ElRotPin, LOW);                  //   deactivate rotation pin - rotate UP
      }
      lcd.setCursor(8, 1);
       lcd.write(2);                                   // arrow up
      ElUp   = 2;                                       // flag for elevation UP
    }
      else {
      if (ElUp == 2) {                                // if previously   rotating in the oposite direction
        analogWrite(ElPWMPin, 0);                     //   STOP the motor
        StaElev = TruElev;                            // this   will be the start elevation for soft-start
        delay(200);                                   //   pre-switch delay
        digitalWrite(ElRotPin, HIGH);                 // deactivate   rotation pin - rotate UP
        delay(200);                                   //   post-switch delay
      }
      else {                                          //   same directin, no Stop, no delay
        digitalWrite(ElRotPin, HIGH);                 //   deactivate rotation pin - rotate UP
      }
        lcd.setCursor(8, 1);
         lcd.write(1);                                 // arrow down
        ElUp   = 1;                                     // flag for elevation DN
    }
 //   this activates azim PWM pin proportional with angle error (calculated in percents   %)
    PwElStop = PwElMin + round((abs(ComElev-TruElev))*(PwElMax-PwElMin)/Emax);    //formula which outputs a power proportional with angle difference for Soft-Stop
     PwElStar = PwElMin + round((abs(StaElev-TruElev))*(PwElMax-PwElMin)/Emax);   //formula   which outputs a power proportional with angle difference for Soft-Start
    if   (PwElStar > PwElStop){
         PwEl = PwElStop;                             //choose   whichever value is smallest
      }
      else {PwEl = PwElStar;}
    if   (PwEl > PwElMax) {PwEl = PwElMax;}
    analogWrite(ElPWMPin, round(2.55*PwEl));           // activate Elev drive PWM pin
}  // end ElevRotate()

void SerComm()   {
  // initialize readings
  ComputerRead = "";
  Azimuth = "";
   Elevation = "";

  while(Serial.available()) {
    ComputerRead= Serial.readString();   // read the incoming data as string
//    Serial.println(ComputerRead);     //   echo the reception for testing purposes
  }
  
// looking for command <AZxxx.x>
     for (int i = 0; i <= ComputerRead.length(); i++) {
     if ((ComputerRead.charAt(i)   == 'A')&&(ComputerRead.charAt(i+1) == 'Z')){ // if read AZ
      for (int j =   i+2; j <= ComputerRead.length(); j++) {
        if (isDigit(ComputerRead.charAt(j)))   {                                // if the character is number
          Azimuth   = Azimuth + ComputerRead.charAt(j);
        }
        else {break;}
      }
      }
    }
    
// looking for command <ELxxx.x>
    for (int i =   0; i <= (ComputerRead.length()-2); i++) {
      if ((ComputerRead.charAt(i) ==   'E')&&(ComputerRead.charAt(i+1) == 'L')){ // if read EL
        if ((ComputerRead.charAt(i+2))   == '-') {
          ComElev = 0;                  // if elevation negative
           break;
        }
        for (int j = i+2; j <= ComputerRead.length();   j++) {
          if (isDigit(ComputerRead.charAt(j))) {                               //   if the character is number
            Elevation = Elevation + ComputerRead.charAt(j);
           }
          else {break;}
        }
      }
    }
    
//   if <AZxx> received
    if (Azimuth != ""){
      ComAzim = Azimuth.toInt();
       ComAzim = ComAzim%360;          // keeping values between limits(for trackers   with more than 360 deg. rotation)
      }

// if <ELxx> received
    if   (Elevation != ""){
      ComElev = Elevation.toInt();
      if (ComElev>180)   { ComElev = 0;}
      if (ComElev>90) {               //if received more than   90deg. (for trackers with 180deg. elevation)
        ComElev = 180-ComElev;        //keep   below 90deg.
        ComAzim = (ComAzim+180)%360;  //and rotate the antenna on   the back
      }
    }

// looking for <AZ EL> interogation for antenna   position
  for (int i = 0; i <= (ComputerRead.length()-4); i++) {
    if ((ComputerRead.charAt(i)   == 'A')&&(ComputerRead.charAt(i+1) == 'Z')&&(ComputerRead.charAt(i+3) == 'E')&&(ComputerRead.charAt(i+4)   == 'L')){
    // send back the antenna position <+xxx.x xx.x>
      ComputerWrite   = "+"+String(TruAzim)+".0 "+String(TruElev)+".0";
    //ComputerWrite =   "AZ"+String(TruAzim)+".0 EL"+String(TruElev)+".0"; //that's for Gpredict and   HamLib
      Serial.println(ComputerWrite);
    }
  }
}  // end SerComm()

ant-rot-AC-aug2022

arduino

This code is for relay output or AC motors. Use electric diagram for AC motors.

1/*  AZ/EL Antenna Rotator controller for Arduino - relay output
2 *  ===========================================================
3 *  Uses EasyComm  protocol for computer - Tracking Software
4 *  Manual command by means of two  rotary encoders AZ - EL
5 *  
6 *  compatible with switch-box rotators 
7  *  or AC motors
8 *  dry contatcts for Left-Right, Up-Down
9 *  
10 *  Viorel  Racoviteannu /
11 *  https://www.youtube.com/channel/UCiRLZX0bV9rS04BGAyUf-fA
12  *  https://racov.ro
13 *  YO3RAK@gmail.com
14 *  
15 * I cannot take any responsibility  for missuse of this code
16 * or any kind of damage it may occur from using this  code.
17 * 
18 * dec 2020 v2 - improved serial comm stability
19 * jan 2021 -  fixed AZ, EL tolerances for motor activation
20 * apr 2021 - improved serial comm  stability
21 * aug 2021 - faster USB update, cold switching Az/El direction, small  optimizations in the code
22 * ian 2022 - small optimizations
23 * aug 2022 -  improved EL encoder functionality, electric diagram modified - encoders connections
24  */
25 
26#include <Wire.h> // Library for I2C communication
27#include <LiquidCrystal_I2C.h>  // https://www.arduinolibraries.info/libraries/liquid-crystal-i2-c (Library for  LCD)
28// Wiring: SDA pin is connected to A4 and SCL pin to A5.
29// Connect to  LCD via I2C, default address 0x27 (A0-A2 not jumpered)
30LiquidCrystal_I2C lcd(0x27,  16, 2); // address, chars, rows.
31
32// declaring custom symbol for up/down arrow
33  byte DownArrow[8] = {
34  B00000,
35  B00100,
36  B00100,
37  B00100,
38  B10101,
39  B01110,
40  B00100,
41  B00000
42};
43 byte UpArrow[8] = {
44  B00000,
45  B00100,
46  B01110,
47  B10101,
48  B00100,
49  B00100,
50  B00100,
51  B00000
52};
53
54//  ANTENNA potentiometers CALIBRATION
55  int AzMin = 1;                     //begining  of the potentiometer
56  int AzMax = 1023;                  //end of the potentiometer  
57  int ElMin = 1;
58  int ElMax = 1023;
59
60// Allowed error for which antenna  won't move
61  int AzErr = 8;
62  int ElErr = 4;
63
64// PIN assignement
65  enum PinAssignment {
66  AzPotPin = A0,                      // input pin for  the azim. potentiometer
67  ElPotPin = A1,                      // input pin for  the elev. potentiometer
68  AzEncoderPinA = 2,                  // Az encoder right
69  AzEncoderPinB = 4,                  // Az encoder left
70  AzClearButton = 5,                  // Az encoder push
71  ElEncoderPinA = 3,                  //  El encoder right
72  ElEncoderPinB = 6,                  // El encoder left
73  ElClearButton = 7,                  // El encoder push
74  ElRotPinD = 8,
75  ElRotPinU = 9,                      // out pin for elevation rotation direction
76  AzRotPinL = 10,
77  AzRotPinR = 11                      // out pin for rotation  direction
78  };
79  
80// Az encoder variables
81  int AzEncBut = 1;                   //  variable to toggle with encoder push button
82  volatile boolean AzEncRot;          //  if rotation occured
83  volatile boolean AzEncUp;           // direction of rotation
84  
85// El encoder variables
86  int ElEncBut = 1;
87  volatile boolean ElEncRot;
88  volatile boolean ElEncUp;
89  
90// movement variables
91  int TruAzim = 0;                    // calculated real azimuth value
92  int ComAzim = 0;                    //  commanded azimuth value
93  int TruElev = 0;                    // calculated real  elevation value
94  int ComElev = 0;                    // commanded elevation  value
95  int OldTruAzim = 0;                 // store previous azimuth values
96  int OldComAzim = 0;
97  int OldTruElev = 0;                 // store previous  elevation values
98  int OldComElev = 0;
99  char AzDir;                         //  symbol for azim rot display
100  char ElDir;                         // symbol for  elev. rot display
101  unsigned long NowTime;              // store the current  millis() for timing purposes
102  
103// flags for AZ, EL tolerances
104  bool AzStop  = false;
105  bool ElStop = false;
106  int ElUp = 0;                       // 1  = Elevation Dn, 0 = Elevation STOP, 2 = Elevation Up
107  
108// averaging loop
109  const int numReadings = 25;
110  int readIndex = 0;                  // the index  of the current reading  
111  int azimuth[numReadings];           // the readings  from the analog input
112  int elevation[numReadings];
113  int totalAz = 0;                    //  the running total
114  int totalEl = 0;
115
116// variables for serial comm
117  String Azimuth = "";
118  String Elevation = "";
119  String ComputerRead;
120  String ComputerWrite;
121  bool AZser = false;
122  bool ELser = false;
123  bool  ANTser = false;
124
125/*************** END VARIABLE DECLARATION  ************/
126  
127void setup() {
128  Serial.begin(9600);
129  Serial.setTimeout(50);         //  miliseconds to wait for USB sata. Default 1000
130// Initiate the LCD:
131//  lcd.begin(16,2);             //select this one if the arrows are not displayed correctly
132  lcd.init();
133  lcd.backlight();
134  
135// write on display name and version
136  lcd.setCursor(0,  0);           // Set the cursor on the first column first row.(counting starts at  0!)
137  lcd.print("EasyCom AntRotor");
138  lcd.setCursor(0, 1);           //  Set the cursor on the first column the second row
139  lcd.print("*Racov* Aug.2022");
140  
141// creating custom symbol for up/dwn arrow
142  lcd.createChar(1, DownArrow);
143  lcd.createChar(2, UpArrow);
144  
145// pin declaration
146  pinMode(AzRotPinR,  OUTPUT);    //declaring  azim. rotation direction Pin as OUTPUT
147  pinMode(AzRotPinL,  OUTPUT);
148  pinMode(ElRotPinD, OUTPUT);    //declaring  elev. rotation direction  Pin as OUTPUT
149  pinMode(ElRotPinU, OUTPUT);
150  pinMode(AzPotPin, INPUT);
151  pinMode(ElPotPin, INPUT);
152  pinMode(AzEncoderPinA, INPUT);
153  pinMode(AzEncoderPinB,  INPUT);
154  pinMode(AzClearButton, INPUT);
155  pinMode(ElEncoderPinA, INPUT);
156  pinMode(ElEncoderPinB, INPUT);
157  pinMode(ElClearButton, INPUT);
158  
159//  deactivate rotation pins
160  digitalWrite(AzRotPinL, LOW);
161  digitalWrite(AzRotPinR,  LOW);
162  digitalWrite(ElRotPinD, LOW);
163  digitalWrite(ElRotPinU, LOW);
164
165//  Interrupt Service Routine for Az and El encoder
166  attachInterrupt(0, doAzEnc,  CHANGE);                               // Az encoder
167  attachInterrupt(1, doElEnc,  CHANGE);                               // El Encoder
168
169/* initialization of  the averaging loop
170   this is to set Az/El-command the same value as real, not  to jerk the antenna at start-up */
171  TruAzim = (map(analogRead(AzPotPin), AzMin,  AzMax, 0, 359));       // transforms potentiometer voltage into azimuth angle
172  TruElev = (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));        // transforms  potentiometer voltage into elevation angle
173
174  for (int thisReading = 0; thisReading  < numReadings; thisReading++) {
175    azimuth[thisReading] = TruAzim;
176    elevation[thisReading]  = TruElev;
177  }
178  totalAz = TruAzim * numReadings;
179  totalEl = TruElev *  numReadings;
180
181/* keep command values in range  */
182  ComAzim = constrain(TruAzim,  0, 359);
183  ComElev = constrain(TruElev, 0, 90);
184  OldTruAzim = TruAzim;
185  OldComAzim = ComAzim;
186  OldTruElev = TruElev;
187  OldComElev = TruElev;
188
189  delay(1500);                                // wait 1.5 seconds
190// display  Azim. and Elev. values
191  lcd.setCursor(0, 0);
192  lcd.print("Azm.---" + String(char(223))  + "=Cd.---" + String(char(223)));  // char(223) is degree symbol
193  lcd.setCursor(0,  1); 
194  lcd.print("Elv. --" + String(char(223)) + "=Cd. --" + String(char(223)));
195  DisplValue(TruAzim, 4,0);
196  DisplValue(ComAzim,12,0);
197  DisplValue(TruElev,  4,1);
198  DisplValue(ComElev,12,1);
199}
200// end SETUP
201  
202void loop() {         /************** FYI, this loop repeats 500 times per second !!! **************/
203
204//  AZIMUTH/ELEVATION AVERAGING LOOP
205  // subtract the oldest value
206  totalAz  = totalAz - azimuth[readIndex];
207  totalEl = totalEl - elevation[readIndex];
208  // read from the sensor:
209  azimuth[readIndex] = (map(analogRead(AzPotPin),  AzMin, AzMax, 0, 359));
210  elevation[readIndex] = (map(analogRead(ElPotPin), ElMin,  ElMax, 0, 90));
211  // add the reading to the total:
212  totalAz = totalAz + azimuth[readIndex];
213  totalEl = totalEl + elevation[readIndex];
214  // do the average
215  TruAzim  = totalAz / numReadings;
216  TruElev = totalEl / numReadings;
217/*  keep values  in range
218  TruAzim = constrain(TruAzim, 0, 359);
219  TruElev = constrain(TruElev,  0, 90); */
220  // advance to the next position in the array
221  // if we're at  the end of the array, wrap around to the beginning:
222  readIndex = (readIndex  + 1) % numReadings;
223  
224// read the command from encoder
225  ReadAzimEncoder();
226  ReadElevEncoder();
227  
228// read the command from computer
229  if (Serial.available())  {SerComm();}        // read USB data
230
231// update antenna position display only  if value change
232  if ((millis() - NowTime) > 300){            //every 0.3 seconds,  not to flicker the display
233    if (OldTruAzim!=TruAzim) {
234      DisplValue(TruAzim,4,0);
235      OldTruAzim = TruAzim;
236    }
237    if (OldTruElev!=TruElev) {
238      DisplValue(TruElev,4,1);
239      OldTruElev = TruElev;
240    }
241    NowTime = millis();
242  }
243  
244//  update target position display only if value change
245  if (OldComAzim != ComAzim)  {
246    DisplValue(ComAzim,12,0);
247    OldComAzim = ComAzim;
248  }
249  if (OldComElev  != ComElev) {
250    DisplValue(ComElev,12,1);
251    OldComElev = ComElev;
252  }
253
254// this is to rotate in azimuth
255  if (TruAzim == ComAzim) {                   //  if equal, stop moving
256    AzStop = true;
257    digitalWrite(AzRotPinL, LOW);             // deactivate rotation pin 
258    digitalWrite(AzRotPinR, LOW);
259    lcd.setCursor(8, 0);
260    lcd.print("=");
261  }
262    else if ((abs(TruAzim  - ComAzim)<=AzErr)&&(AzStop == false)) {  // if in tolerance, but it wasn't an equal,  rotate
263      AzimRotate();}
264    else if (abs(TruAzim - ComAzim)>AzErr){   //  if target is off tolerance
265      AzStop = false;                         // it's  not equal
266      AzimRotate();                           // rotate
267    }
268
269//  this is to rotate in elevation
270  if (TruElev == ComElev) {                   //  if equal, stop moving
271    ElStop = true;
272    digitalWrite(ElRotPinD, LOW);             // deactivate elevator pin
273    digitalWrite(ElRotPinU, LOW);
274    lcd.setCursor(8, 1);
275    lcd.print("=");
276    ElUp = 0;                                 //  flag for elevation STOP
277  }
278    else if ((abs(TruElev - ComElev)<=ElErr)&&(ElStop  == false)) {  // if in tolerance, but it wasn't an equal, rotate
279      ElevRotate();}
280    else if (abs(TruElev - ComElev)>ElErr){   // if target is off tolerance
281      ElStop = false;                         // it's not equal
282      ElevRotate();                           // rotate
283    }
284
285// this is to interpret x10  AZ ENC multiplication
286  while (AzEncBut == 10) {                    // while  toggled to x10
287    digitalWrite(AzRotPinL, LOW);             // deactivate rotation  pin 
288    digitalWrite(AzRotPinR, LOW);
289    digitalWrite(ElRotPinD, LOW);             //  deactivate elevator pin
290    digitalWrite(ElRotPinU, LOW);
291    lcd.setCursor(8,  0);
292    lcd.print("*");
293    ReadAzimEncoder();
294    if (OldComAzim !=  ComAzim){               // update display only if numbers change
295      DisplValue(ComAzim,  12, 0);
296      OldComAzim = ComAzim;
297    }
298    ReadElevEncoder();
299    if  (OldComElev != ComElev){               // update display only if numbers change
300      DisplValue(ComElev, 12, 1);
301      OldComElev = ComElev;
302    }
303    delay(100);
304  }
305}
306// end main LOOP
307
308//____________________________________________________
309//  ___________procedures definitions__________________
310
311void DisplValue(int x,  int y, int z) {
312  char displayString[7] = "";
313  sprintf(displayString, "%3d",  x);           // outputs a fixed lenght number (3 integer)
314  lcd.setCursor(y,  z);                        // for leading zeros '007' use "%03d"
315  lcd.print(displayString);
316  
317// ************** FOR CALIBRATION PURPOSES **************
318/*
319  Serial.print  ("Az ");
320  Serial.println (analogRead(AzPotPin));
321  Serial.print ("El ");
322  Serial.println (analogRead(ElPotPin));
323*/
324}  // end DisplValue()
325
326void  ReadAzimEncoder() {
327  if (digitalRead(AzClearButton) == LOW )  {      // if encoder  switch depressed
328    delay (250);                                  // debounce  switch
329    lcd.setCursor(0, 0);                          // refresh all the writings  on the screen
330    lcd.print("Azm.---" + String(char(223)) + "=Cd.---" + String(char(223)));
331    lcd.setCursor(0, 1); 
332    lcd.print("Elv. --" + String(char(223)) + "=Cd.  --" + String(char(223)));
333    DisplValue(TruAzim, 4,0);
334    DisplValue(ComAzim,12,0);
335    DisplValue(TruElev, 4,1);
336    DisplValue(ComElev,12,1);
337    if (AzEncBut  == 1){
338      AzEncBut = 10;                              // increment by 10 degrees
339      ComAzim = int(ComAzim/10)*10;               // ComAzim in 10deg. steps 
340    }
341    else
342      AzEncBut = 1;
343  }
344
345  if (AzEncRot){
346    delay(20);                                    // debouncing
347    if (AzEncUp)
348      ComAzim  += AzEncBut;
349    else
350      ComAzim -= AzEncBut;
351    ComAzim = ((ComAzim  + 360) % 360);            // Az Cmd between 0 and 359 deg continuous
352    AzEncRot  = false;
353  }
354} //end ReadAzimEncoder()
355
356void ReadElevEncoder() {
357  if (digitalRead(ElClearButton) == LOW )  {      // set Park Position Command Az/El
358    delay(250);                                   // debounce switch
359    ComAzim  = 260;
360    ComElev = 0;
361  }
362
363  if (ElEncRot){
364    delay(20);                                    //  debouncing
365    if (ElEncUp)
366      ComElev ++;
367    else
368      ComElev  --;
369    ComElev = constrain(ComElev, 0, 90);          // keep El Cmd value in  range
370    ElEncRot = false;
371  }
372}  // end of ReadElevEncoder()
373
374//  Interrupt Service Routine for a change to encoder pin A and B
375void doAzEnc ()
376{
377  if (digitalRead (AzEncoderPinA))
378    AzEncUp = digitalRead (AzEncoderPinB);
379  else
380    AzEncUp = !digitalRead (AzEncoderPinB);
381  AzEncRot = true;
382}  // end of doAzEnc
383
384void doElEnc ()
385{
386  if (digitalRead (ElEncoderPinA))
387    ElEncUp = digitalRead (ElEncoderPinB);
388  else
389    ElEncUp = !digitalRead  (ElEncoderPinB);
390    ElEncRot = true;
391}  // end of doElEnc
392
393void AzimRotate()  {
394    if (ComAzim > TruAzim) {                     // this to determine direction  of rotation
395// cold switching - stop motor before changing direction, to protect  mechanic and electric parts
396      digitalWrite(AzRotPinL, LOW);              //  deactivate rotation pin Left
397      if (AzDir == char(127)) {delay(1000);}     //  if previously rotating in the oposite direction, wait 1 second
398      digitalWrite(AzRotPinR,  HIGH);             // activate rotation pin Right
399      AzDir = char(126);                         //  "->"
400    }                           
401    else {
402      digitalWrite(AzRotPinR,  LOW);
403      if (AzDir == char(126)) {delay(1000);}
404      digitalWrite(AzRotPinL,  HIGH);
405      AzDir = char(127);                         // "<-"
406    }
407  lcd.setCursor(8, 0);
408  lcd.print(String(AzDir));
409}  // end AzimRotate()
410
411void  ElevRotate() {
412// this to determine direction of rotation
413    if (ComElev  > TruElev) {
414      digitalWrite(ElRotPinD, LOW);
415      if (ElUp == 1) {delay(1000);}
416      digitalWrite(ElRotPinU, HIGH);
417      lcd.setCursor(8, 1);
418      lcd.write(2);                              // arrow up
419      ElUp = 2;
420    }
421     else  {
422      digitalWrite(ElRotPinU, LOW);
423      if (ElUp == 2) {delay(1000);}
424      digitalWrite(ElRotPinD, HIGH);
425      lcd.setCursor(8, 1);
426      lcd.write(1);                              // arrow down
427      ElUp = 1;
428    }
429}  //  end ElevRotate()
430
431void SerComm() {
432  // initialize readings
433  ComputerRead  = "";
434  Azimuth = "";
435  Elevation = "";
436
437  while(Serial.available())  {
438    ComputerRead= Serial.readString();           // read the incoming data  as string
439//    Serial.println(ComputerRead);              // echo the reception  for testing purposes
440  }
441  
442// looking for command <AZxxx.x>
443    for  (int i = 0; i <= ComputerRead.length(); i++) {
444     if ((ComputerRead.charAt(i)  == 'A')&&(ComputerRead.charAt(i+1) == 'Z')){ // if read AZ
445      for (int j =  i+2; j <= ComputerRead.length(); j++) {
446        if (isDigit(ComputerRead.charAt(j)))  {                                // if the character is number
447          Azimuth  = Azimuth + ComputerRead.charAt(j);
448        }
449        else {break;}
450      }
451     }
452    }
453    
454// looking for command <ELxxx.x>
455    for (int i =  0; i <= (ComputerRead.length()-2); i++) {
456      if ((ComputerRead.charAt(i) ==  'E')&&(ComputerRead.charAt(i+1) == 'L')){ // if read EL
457        if ((ComputerRead.charAt(i+2))  == '-') {                               // if received elevation negative
458          ComElev  = 0;                                                         // keep antenna to  zero
459          break;
460        }
461        for (int j = i+2; j <= ComputerRead.length();  j++) {
462          if (isDigit(ComputerRead.charAt(j))) {                               //  if the character is number
463            Elevation = Elevation + ComputerRead.charAt(j);
464          }
465          else {break;}
466        }
467      }
468    }
469    
470//  if <AZxx> received
471    if (Azimuth != ""){
472      ComAzim = Azimuth.toInt();
473      ComAzim = ComAzim%360;          // keeping values in range
474    }
475
476//  if <ELxx> received
477    if (Elevation != ""){
478      ComElev = Elevation.toInt();
479      if (ComElev>180) { ComElev = 0;}
480      if (ComElev>90) {               //  if received more than 90deg. (for trackers with 180deg. elevation)
481        ComElev  = 180-ComElev;        //keep below 90deg.
482        ComAzim = (ComAzim+180)%360;  //and rotate the antenna on the back
483      }
484    }
485
486// looking for  <AZ EL> interogation for antenna position
487  for (int i = 0; i <= (ComputerRead.length()-4);  i++) {
488    if ((ComputerRead.charAt(i) == 'A')&&(ComputerRead.charAt(i+1) ==  'Z')&&(ComputerRead.charAt(i+3) == 'E')&&(ComputerRead.charAt(i+4) == 'L')){
489    // send back the antenna position <+xxx.x xx.x>
490      ComputerWrite = "+"+String(TruAzim)+".0  "+String(TruElev)+".0";
491 //ComputerWrite = "AZ"+String(TruAzim)+".0 EL"+String(TruElev)+".0";  //that's for Gpredict and HamLib
492      Serial.println(ComputerWrite);
493    }
494  }
495}  // end SerComm()
496

/*  AZ/EL Antenna Rotator controller for Arduino - relay output
 *  ===========================================================
 *  Uses EasyComm  protocol for computer - Tracking Software
 *  Manual command by means of two  rotary encoders AZ - EL
 *  
 *  compatible with switch-box rotators 
  *  or AC motors
 *  dry contatcts for Left-Right, Up-Down
 *  
 *  Viorel  Racoviteannu /
 *  https://www.youtube.com/channel/UCiRLZX0bV9rS04BGAyUf-fA
  *  https://racov.ro
 *  YO3RAK@gmail.com
 *  
 * I cannot take any responsibility  for missuse of this code
 * or any kind of damage it may occur from using this  code.
 * 
 * dec 2020 v2 - improved serial comm stability
 * jan 2021 -  fixed AZ, EL tolerances for motor activation
 * apr 2021 - improved serial comm  stability
 * aug 2021 - faster USB update, cold switching Az/El direction, small  optimizations in the code
 * ian 2022 - small optimizations
 * aug 2022 -  improved EL encoder functionality, electric diagram modified - encoders connections
  */
 
#include <Wire.h> // Library for I2C communication
#include <LiquidCrystal_I2C.h>  // https://www.arduinolibraries.info/libraries/liquid-crystal-i2-c (Library for  LCD)
// Wiring: SDA pin is connected to A4 and SCL pin to A5.
// Connect to  LCD via I2C, default address 0x27 (A0-A2 not jumpered)
LiquidCrystal_I2C lcd(0x27,  16, 2); // address, chars, rows.

// declaring custom symbol for up/down arrow
  byte DownArrow[8] = {
  B00000,
  B00100,
  B00100,
  B00100,
  B10101,
  B01110,
  B00100,
  B00000
};
 byte UpArrow[8] = {
  B00000,
  B00100,
  B01110,
  B10101,
  B00100,
  B00100,
  B00100,
  B00000
};

//  ANTENNA potentiometers CALIBRATION
  int AzMin = 1;                     //begining  of the potentiometer
  int AzMax = 1023;                  //end of the potentiometer  
  int ElMin = 1;
  int ElMax = 1023;

// Allowed error for which antenna  won't move
  int AzErr = 8;
  int ElErr = 4;

// PIN assignement
  enum PinAssignment {
  AzPotPin = A0,                      // input pin for  the azim. potentiometer
  ElPotPin = A1,                      // input pin for  the elev. potentiometer
  AzEncoderPinA = 2,                  // Az encoder right
  AzEncoderPinB = 4,                  // Az encoder left
  AzClearButton = 5,                  // Az encoder push
  ElEncoderPinA = 3,                  //  El encoder right
  ElEncoderPinB = 6,                  // El encoder left
  ElClearButton = 7,                  // El encoder push
  ElRotPinD = 8,
  ElRotPinU = 9,                      // out pin for elevation rotation direction
  AzRotPinL = 10,
  AzRotPinR = 11                      // out pin for rotation  direction
  };
  
// Az encoder variables
  int AzEncBut = 1;                   //  variable to toggle with encoder push button
  volatile boolean AzEncRot;          //  if rotation occured
  volatile boolean AzEncUp;           // direction of rotation
  
// El encoder variables
  int ElEncBut = 1;
  volatile boolean ElEncRot;
  volatile boolean ElEncUp;
  
// movement variables
  int TruAzim = 0;                    // calculated real azimuth value
  int ComAzim = 0;                    //  commanded azimuth value
  int TruElev = 0;                    // calculated real  elevation value
  int ComElev = 0;                    // commanded elevation  value
  int OldTruAzim = 0;                 // store previous azimuth values
  int OldComAzim = 0;
  int OldTruElev = 0;                 // store previous  elevation values
  int OldComElev = 0;
  char AzDir;                         //  symbol for azim rot display
  char ElDir;                         // symbol for  elev. rot display
  unsigned long NowTime;              // store the current  millis() for timing purposes
  
// flags for AZ, EL tolerances
  bool AzStop  = false;
  bool ElStop = false;
  int ElUp = 0;                       // 1  = Elevation Dn, 0 = Elevation STOP, 2 = Elevation Up
  
// averaging loop
  const int numReadings = 25;
  int readIndex = 0;                  // the index  of the current reading  
  int azimuth[numReadings];           // the readings  from the analog input
  int elevation[numReadings];
  int totalAz = 0;                    //  the running total
  int totalEl = 0;

// variables for serial comm
  String Azimuth = "";
  String Elevation = "";
  String ComputerRead;
  String ComputerWrite;
  bool AZser = false;
  bool ELser = false;
  bool  ANTser = false;

/*************** END VARIABLE DECLARATION  ************/
  
void setup() {
  Serial.begin(9600);
  Serial.setTimeout(50);         //  miliseconds to wait for USB sata. Default 1000
// Initiate the LCD:
//  lcd.begin(16,2);             //select this one if the arrows are not displayed correctly
  lcd.init();
  lcd.backlight();
  
// write on display name and version
  lcd.setCursor(0,  0);           // Set the cursor on the first column first row.(counting starts at  0!)
  lcd.print("EasyCom AntRotor");
  lcd.setCursor(0, 1);           //  Set the cursor on the first column the second row
  lcd.print("*Racov* Aug.2022");
  
// creating custom symbol for up/dwn arrow
  lcd.createChar(1, DownArrow);
  lcd.createChar(2, UpArrow);
  
// pin declaration
  pinMode(AzRotPinR,  OUTPUT);    //declaring  azim. rotation direction Pin as OUTPUT
  pinMode(AzRotPinL,  OUTPUT);
  pinMode(ElRotPinD, OUTPUT);    //declaring  elev. rotation direction  Pin as OUTPUT
  pinMode(ElRotPinU, OUTPUT);
  pinMode(AzPotPin, INPUT);
  pinMode(ElPotPin, INPUT);
  pinMode(AzEncoderPinA, INPUT);
  pinMode(AzEncoderPinB,  INPUT);
  pinMode(AzClearButton, INPUT);
  pinMode(ElEncoderPinA, INPUT);
  pinMode(ElEncoderPinB, INPUT);
  pinMode(ElClearButton, INPUT);
  
//  deactivate rotation pins
  digitalWrite(AzRotPinL, LOW);
  digitalWrite(AzRotPinR,  LOW);
  digitalWrite(ElRotPinD, LOW);
  digitalWrite(ElRotPinU, LOW);

//  Interrupt Service Routine for Az and El encoder
  attachInterrupt(0, doAzEnc,  CHANGE);                               // Az encoder
  attachInterrupt(1, doElEnc,  CHANGE);                               // El Encoder

/* initialization of  the averaging loop
   this is to set Az/El-command the same value as real, not  to jerk the antenna at start-up */
  TruAzim = (map(analogRead(AzPotPin), AzMin,  AzMax, 0, 359));       // transforms potentiometer voltage into azimuth angle
  TruElev = (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));        // transforms  potentiometer voltage into elevation angle

  for (int thisReading = 0; thisReading  < numReadings; thisReading++) {
    azimuth[thisReading] = TruAzim;
    elevation[thisReading]  = TruElev;
  }
  totalAz = TruAzim * numReadings;
  totalEl = TruElev *  numReadings;

/* keep command values in range  */
  ComAzim = constrain(TruAzim,  0, 359);
  ComElev = constrain(TruElev, 0, 90);
  OldTruAzim = TruAzim;
  OldComAzim = ComAzim;
  OldTruElev = TruElev;
  OldComElev = TruElev;

  delay(1500);                                // wait 1.5 seconds
// display  Azim. and Elev. values
  lcd.setCursor(0, 0);
  lcd.print("Azm.---" + String(char(223))  + "=Cd.---" + String(char(223)));  // char(223) is degree symbol
  lcd.setCursor(0,  1); 
  lcd.print("Elv. --" + String(char(223)) + "=Cd. --" + String(char(223)));
  DisplValue(TruAzim, 4,0);
  DisplValue(ComAzim,12,0);
  DisplValue(TruElev,  4,1);
  DisplValue(ComElev,12,1);
}
// end SETUP
  
void loop() {         /************** FYI, this loop repeats 500 times per second !!! **************/

//  AZIMUTH/ELEVATION AVERAGING LOOP
  // subtract the oldest value
  totalAz  = totalAz - azimuth[readIndex];
  totalEl = totalEl - elevation[readIndex];
  // read from the sensor:
  azimuth[readIndex] = (map(analogRead(AzPotPin),  AzMin, AzMax, 0, 359));
  elevation[readIndex] = (map(analogRead(ElPotPin), ElMin,  ElMax, 0, 90));
  // add the reading to the total:
  totalAz = totalAz + azimuth[readIndex];
  totalEl = totalEl + elevation[readIndex];
  // do the average
  TruAzim  = totalAz / numReadings;
  TruElev = totalEl / numReadings;
/*  keep values  in range
  TruAzim = constrain(TruAzim, 0, 359);
  TruElev = constrain(TruElev,  0, 90); */
  // advance to the next position in the array
  // if we're at  the end of the array, wrap around to the beginning:
  readIndex = (readIndex  + 1) % numReadings;
  
// read the command from encoder
  ReadAzimEncoder();
  ReadElevEncoder();
  
// read the command from computer
  if (Serial.available())  {SerComm();}        // read USB data

// update antenna position display only  if value change
  if ((millis() - NowTime) > 300){            //every 0.3 seconds,  not to flicker the display
    if (OldTruAzim!=TruAzim) {
      DisplValue(TruAzim,4,0);
      OldTruAzim = TruAzim;
    }
    if (OldTruElev!=TruElev) {
      DisplValue(TruElev,4,1);
      OldTruElev = TruElev;
    }
    NowTime = millis();
  }
  
//  update target position display only if value change
  if (OldComAzim != ComAzim)  {
    DisplValue(ComAzim,12,0);
    OldComAzim = ComAzim;
  }
  if (OldComElev  != ComElev) {
    DisplValue(ComElev,12,1);
    OldComElev = ComElev;
  }

// this is to rotate in azimuth
  if (TruAzim == ComAzim) {                   //  if equal, stop moving
    AzStop = true;
    digitalWrite(AzRotPinL, LOW);             // deactivate rotation pin 
    digitalWrite(AzRotPinR, LOW);
    lcd.setCursor(8, 0);
    lcd.print("=");
  }
    else if ((abs(TruAzim  - ComAzim)<=AzErr)&&(AzStop == false)) {  // if in tolerance, but it wasn't an equal,  rotate
      AzimRotate();}
    else if (abs(TruAzim - ComAzim)>AzErr){   //  if target is off tolerance
      AzStop = false;                         // it's  not equal
      AzimRotate();                           // rotate
    }

//  this is to rotate in elevation
  if (TruElev == ComElev) {                   //  if equal, stop moving
    ElStop = true;
    digitalWrite(ElRotPinD, LOW);             // deactivate elevator pin
    digitalWrite(ElRotPinU, LOW);
    lcd.setCursor(8, 1);
    lcd.print("=");
    ElUp = 0;                                 //  flag for elevation STOP
  }
    else if ((abs(TruElev - ComElev)<=ElErr)&&(ElStop  == false)) {  // if in tolerance, but it wasn't an equal, rotate
      ElevRotate();}
    else if (abs(TruElev - ComElev)>ElErr){   // if target is off tolerance
      ElStop = false;                         // it's not equal
      ElevRotate();                           // rotate
    }

// this is to interpret x10  AZ ENC multiplication
  while (AzEncBut == 10) {                    // while  toggled to x10
    digitalWrite(AzRotPinL, LOW);             // deactivate rotation  pin 
    digitalWrite(AzRotPinR, LOW);
    digitalWrite(ElRotPinD, LOW);             //  deactivate elevator pin
    digitalWrite(ElRotPinU, LOW);
    lcd.setCursor(8,  0);
    lcd.print("*");
    ReadAzimEncoder();
    if (OldComAzim !=  ComAzim){               // update display only if numbers change
      DisplValue(ComAzim,  12, 0);
      OldComAzim = ComAzim;
    }
    ReadElevEncoder();
    if  (OldComElev != ComElev){               // update display only if numbers change
      DisplValue(ComElev, 12, 1);
      OldComElev = ComElev;
    }
    delay(100);
  }
}
// end main LOOP

//____________________________________________________
//  ___________procedures definitions__________________

void DisplValue(int x,  int y, int z) {
  char displayString[7] = "";
  sprintf(displayString, "%3d",  x);           // outputs a fixed lenght number (3 integer)
  lcd.setCursor(y,  z);                        // for leading zeros '007' use "%03d"
  lcd.print(displayString);
  
// ************** FOR CALIBRATION PURPOSES **************
/*
  Serial.print  ("Az ");
  Serial.println (analogRead(AzPotPin));
  Serial.print ("El ");
  Serial.println (analogRead(ElPotPin));
*/
}  // end DisplValue()

void  ReadAzimEncoder() {
  if (digitalRead(AzClearButton) == LOW )  {      // if encoder  switch depressed
    delay (250);                                  // debounce  switch
    lcd.setCursor(0, 0);                          // refresh all the writings  on the screen
    lcd.print("Azm.---" + String(char(223)) + "=Cd.---" + String(char(223)));
    lcd.setCursor(0, 1); 
    lcd.print("Elv. --" + String(char(223)) + "=Cd.  --" + String(char(223)));
    DisplValue(TruAzim, 4,0);
    DisplValue(ComAzim,12,0);
    DisplValue(TruElev, 4,1);
    DisplValue(ComElev,12,1);
    if (AzEncBut  == 1){
      AzEncBut = 10;                              // increment by 10 degrees
      ComAzim = int(ComAzim/10)*10;               // ComAzim in 10deg. steps 
    }
    else
      AzEncBut = 1;
  }

  if (AzEncRot){
    delay(20);                                    // debouncing
    if (AzEncUp)
      ComAzim  += AzEncBut;
    else
      ComAzim -= AzEncBut;
    ComAzim = ((ComAzim  + 360) % 360);            // Az Cmd between 0 and 359 deg continuous
    AzEncRot  = false;
  }
} //end ReadAzimEncoder()

void ReadElevEncoder() {
  if (digitalRead(ElClearButton) == LOW )  {      // set Park Position Command Az/El
    delay(250);                                   // debounce switch
    ComAzim  = 260;
    ComElev = 0;
  }

  if (ElEncRot){
    delay(20);                                    //  debouncing
    if (ElEncUp)
      ComElev ++;
    else
      ComElev  --;
    ComElev = constrain(ComElev, 0, 90);          // keep El Cmd value in  range
    ElEncRot = false;
  }
}  // end of ReadElevEncoder()

//  Interrupt Service Routine for a change to encoder pin A and B
void doAzEnc ()
{
  if (digitalRead (AzEncoderPinA))
    AzEncUp = digitalRead (AzEncoderPinB);
  else
    AzEncUp = !digitalRead (AzEncoderPinB);
  AzEncRot = true;
}  // end of doAzEnc

void doElEnc ()
{
  if (digitalRead (ElEncoderPinA))
    ElEncUp = digitalRead (ElEncoderPinB);
  else
    ElEncUp = !digitalRead  (ElEncoderPinB);
    ElEncRot = true;
}  // end of doElEnc

void AzimRotate()  {
    if (ComAzim > TruAzim) {                     // this to determine direction  of rotation
// cold switching - stop motor before changing direction, to protect  mechanic and electric parts
      digitalWrite(AzRotPinL, LOW);              //  deactivate rotation pin Left
      if (AzDir == char(127)) {delay(1000);}     //  if previously rotating in the oposite direction, wait 1 second
      digitalWrite(AzRotPinR,  HIGH);             // activate rotation pin Right
      AzDir = char(126);                         //  "->"
    }                           
    else {
      digitalWrite(AzRotPinR,  LOW);
      if (AzDir == char(126)) {delay(1000);}
      digitalWrite(AzRotPinL,  HIGH);
      AzDir = char(127);                         // "<-"
    }
  lcd.setCursor(8, 0);
  lcd.print(String(AzDir));
}  // end AzimRotate()

void  ElevRotate() {
// this to determine direction of rotation
    if (ComElev  > TruElev) {
      digitalWrite(ElRotPinD, LOW);
      if (ElUp == 1) {delay(1000);}
      digitalWrite(ElRotPinU, HIGH);
      lcd.setCursor(8, 1);
      lcd.write(2);                              // arrow up
      ElUp = 2;
    }
     else  {
      digitalWrite(ElRotPinU, LOW);
      if (ElUp == 2) {delay(1000);}
      digitalWrite(ElRotPinD, HIGH);
      lcd.setCursor(8, 1);
      lcd.write(1);                              // arrow down
      ElUp = 1;
    }
}  //  end ElevRotate()

void SerComm() {
  // initialize readings
  ComputerRead  = "";
  Azimuth = "";
  Elevation = "";

  while(Serial.available())  {
    ComputerRead= Serial.readString();           // read the incoming data  as string
//    Serial.println(ComputerRead);              // echo the reception  for testing purposes
  }
  
// looking for command <AZxxx.x>
    for  (int i = 0; i <= ComputerRead.length(); i++) {
     if ((ComputerRead.charAt(i)  == 'A')&&(ComputerRead.charAt(i+1) == 'Z')){ // if read AZ
      for (int j =  i+2; j <= ComputerRead.length(); j++) {
        if (isDigit(ComputerRead.charAt(j)))  {                                // if the character is number
          Azimuth  = Azimuth + ComputerRead.charAt(j);
        }
        else {break;}
      }
     }
    }
    
// looking for command <ELxxx.x>
    for (int i =  0; i <= (ComputerRead.length()-2); i++) {
      if ((ComputerRead.charAt(i) ==  'E')&&(ComputerRead.charAt(i+1) == 'L')){ // if read EL
        if ((ComputerRead.charAt(i+2))  == '-') {                               // if received elevation negative
          ComElev  = 0;                                                         // keep antenna to  zero
          break;
        }
        for (int j = i+2; j <= ComputerRead.length();  j++) {
          if (isDigit(ComputerRead.charAt(j))) {                               //  if the character is number
            Elevation = Elevation + ComputerRead.charAt(j);
          }
          else {break;}
        }
      }
    }
    
//  if <AZxx> received
    if (Azimuth != ""){
      ComAzim = Azimuth.toInt();
      ComAzim = ComAzim%360;          // keeping values in range
    }

//  if <ELxx> received
    if (Elevation != ""){
      ComElev = Elevation.toInt();
      if (ComElev>180) { ComElev = 0;}
      if (ComElev>90) {               //  if received more than 90deg. (for trackers with 180deg. elevation)
        ComElev  = 180-ComElev;        //keep below 90deg.
        ComAzim = (ComAzim+180)%360;  //and rotate the antenna on the back
      }
    }

// looking for  <AZ EL> interogation for antenna position
  for (int i = 0; i <= (ComputerRead.length()-4);  i++) {
    if ((ComputerRead.charAt(i) == 'A')&&(ComputerRead.charAt(i+1) ==  'Z')&&(ComputerRead.charAt(i+3) == 'E')&&(ComputerRead.charAt(i+4) == 'L')){
    // send back the antenna position <+xxx.x xx.x>
      ComputerWrite = "+"+String(TruAzim)+".0  "+String(TruElev)+".0";
 //ComputerWrite = "AZ"+String(TruAzim)+".0 EL"+String(TruElev)+".0";  //that's for Gpredict and HamLib
      Serial.println(ComputerWrite);
    }
  }
}  // end SerComm()

Potentiometer calibration procedure

arduino

AZ / EL Potentiometers limit calibration PROCEDURE for displaying the correct antenna angles and rotation limits ( 0-359ᴼ / 0-90ᴼ) This is plain text, not a code :)

1AZ / EL Potentiometers limit calibration PROCEDURE  ( 0-359ᴼ /  0-90ᴼ)
2  
31. Open the code in Arduino and
4- Look for:
5
6// ************** FOR  CALIBRATION PURPOSES **************
7/*
8  Serial.print ("Az ");
9  Serial.println  (analogRead(AzPotPin));
10  Serial.print ("El ");
11  Serial.println (analogRead(ElPotPin));
12*/
13
14-  Eliminate the simbols /* and */
15- The text above should turn from gray into black  and coloured.
16
17
182. Upload the code and open the serial monitor. There you  will see a lot of numbers;
19
203. With the help of the encoders, move the antenna  to minimum values, 0ᴼ in azimuth and 0ᴼ in elevation.
21- Write down the values  for Azimuth and Elevation. (in my case it was AzMin=90, ElMin=10)
22- These are  the input values read by Arduino, not the real angles;
23
244. Move the antenna  again to maximum values,  359ᴼ in azimuth and 90ᴼ in elevation.
25- Again, write  down the values for Azimuth and Elevation. (in my case it was AzMax=1000, ElMax=992);
26
275.  Look in the code, at the beginning, for the section
28
29// ANTENNA potentiometers  CALIBRATION
30  int AzMin = 1;
31  int AzMax = 1023;
32  int ElMin = 1;
33  int  ElMax = 1023;
34
35- Here input the values you wrote down earlier, like
36  int  AzMin = 90;
37  int AzMax = 1000;
38  int ElMin = 10;
39  int ElMax = 992;
40
416.  Now it is no longer necessary to send this on serial, so you have to comment back  these lines, like this:
42/*
43  Serial.print ("Az ");
44  Serial.println (analogRead(AzPotPin));
45  Serial.print ("El ");
46  Serial.println (analogRead(ElPotPin));
47*/
48-  The text above should turn gray
49
507. Upload again the code.
51
52That's all.  Now, in the serial monitor, there should be no more numbers.

AZ / EL Potentiometers limit calibration PROCEDURE  ( 0-359ᴼ /  0-90ᴼ)
  
1. Open the code in Arduino and
- Look for:

// ************** FOR  CALIBRATION PURPOSES **************
/*
  Serial.print ("Az ");
  Serial.println  (analogRead(AzPotPin));
  Serial.print ("El ");
  Serial.println (analogRead(ElPotPin));
*/

-  Eliminate the simbols /* and */
- The text above should turn from gray into black  and coloured.


2. Upload the code and open the serial monitor. There you  will see a lot of numbers;

3. With the help of the encoders, move the antenna  to minimum values, 0ᴼ in azimuth and 0ᴼ in elevation.
- Write down the values  for Azimuth and Elevation. (in my case it was AzMin=90, ElMin=10)
- These are  the input values read by Arduino, not the real angles;

4. Move the antenna  again to maximum values,  359ᴼ in azimuth and 90ᴼ in elevation.
- Again, write  down the values for Azimuth and Elevation. (in my case it was AzMax=1000, ElMax=992);

5.  Look in the code, at the beginning, for the section

// ANTENNA potentiometers  CALIBRATION
  int AzMin = 1;
  int AzMax = 1023;
  int ElMin = 1;
  int  ElMax = 1023;

- Here input the values you wrote down earlier, like
  int  AzMin = 90;
  int AzMax = 1000;
  int ElMin = 10;
  int ElMax = 992;

6.  Now it is no longer necessary to send this on serial, so you have to comment back  these lines, like this:
/*
  Serial.print ("Az ");
  Serial.println (analogRead(AzPotPin));
  Serial.print ("El ");
  Serial.println (analogRead(ElPotPin));
*/
-  The text above should turn gray

7. Upload again the code.

That's all.  Now, in the serial monitor, there should be no more numbers.

Motor calibration procedure

arduino

This procedure sets the parameters for the Antenna Speed-Up / Slow-Down Zone. This is plain text, not a code :)

1Motor Calibration Procedure For Soft-Start / Soft-Stop feature.
2This  procedure sets the parameters for the Antenna Speed-Up / Slow-Down and the Dead-Zone.
3You  basically set how fast and how slow you want the antenna to start and to stop. You  also set much the target can move, before the antenna will adjust again.
4It’s  not strictly necessary, only if you don’t like the default settings.
5Make sure  you first apply the Potentiometer Calibration Procedure !!! That one is strictly  necessary.
6Look at the power diagram for a better understanding.
7
8***For  Azimuth movement***
9-As the antenna starts to move towards the target, is picking  up speed, reaching full power after <Amax> degrees difference. 
10-As the antenna  closes in to the target, below <Amax> degrees difference, it starts to slow down.  <Amax> should be higher for heavier antennas.
11-The power starts to decrease from  <PwAzMax> to <PwAzMin> until the angle difference becomes zero.
12  <PwAzMax> (in  percents %) should be 100 for full speed. If you ever think your antenna rotates  too fast, you can set a smaller <PwAzMax>.
13  <PwAzMin> (in percents %) is the  minimum power for which your motor doesn’t stall and can start under load. The power  output never falls below this value.
14-Once the antenna reaches the target position  (zero degrees error), it stops and doesn’t move again until the target travels more  than <AzErr> degrees.
15  This is a dead zone, to prevent continuously shaking  the antenna for the smallest target movement, or potentiometer position jitter.
16  The smaller the <AzErr>, the more precise tracking, the more frequent shacking  of the motors.
17
18***For Elevation movement***
19Exactly as for the Azimuth.
20
21Look  at the beginning of the code for this section. Here you can input your  desired  values.
22
23/**************THIS IS WHERE YOU REALY TWEAK THE ANTENNA MOVEMENT************/
24...
25
26//  Allowed error for which antennna won't move.
27  int AzErr = 8;
28  int ElErr  = 4;
29
30// Angle difference where soft stop begins
31  int Amax = 25;        //azimuth
32  int Emax = 15;        //elevation
33
34// min and max power for motors, percents;
35  int PwAzMin = 30;     //minimum power for which the motor doesn't stall and starts  under load
36  int PwAzMax = 100;    //full power for the fastest speed
37  int  PwElMin = 30;
38  int PwElMax = 100;
39/****************************************************************************/

Motor Calibration Procedure For Soft-Start / Soft-Stop feature.
This  procedure sets the parameters for the Antenna Speed-Up / Slow-Down and the Dead-Zone.
You  basically set how fast and how slow you want the antenna to start and to stop. You  also set much the target can move, before the antenna will adjust again.
It’s  not strictly necessary, only if you don’t like the default settings.
Make sure  you first apply the Potentiometer Calibration Procedure !!! That one is strictly  necessary.
Look at the power diagram for a better understanding.

***For  Azimuth movement***
-As the antenna starts to move towards the target, is picking  up speed, reaching full power after <Amax> degrees difference. 
-As the antenna  closes in to the target, below <Amax> degrees difference, it starts to slow down.  <Amax> should be higher for heavier antennas.
-The power starts to decrease from  <PwAzMax> to <PwAzMin> until the angle difference becomes zero.
  <PwAzMax> (in  percents %) should be 100 for full speed. If you ever think your antenna rotates  too fast, you can set a smaller <PwAzMax>.
  <PwAzMin> (in percents %) is the  minimum power for which your motor doesn’t stall and can start under load. The power  output never falls below this value.
-Once the antenna reaches the target position  (zero degrees error), it stops and doesn’t move again until the target travels more  than <AzErr> degrees.
  This is a dead zone, to prevent continuously shaking  the antenna for the smallest target movement, or potentiometer position jitter.
  The smaller the <AzErr>, the more precise tracking, the more frequent shacking  of the motors.

***For Elevation movement***
Exactly as for the Azimuth.

Look  at the beginning of the code for this section. Here you can input your  desired  values.

/**************THIS IS WHERE YOU REALY TWEAK THE ANTENNA MOVEMENT************/
...

//  Allowed error for which antennna won't move.
  int AzErr = 8;
  int ElErr  = 4;

// Angle difference where soft stop begins
  int Amax = 25;        //azimuth
  int Emax = 15;        //elevation

// min and max power for motors, percents;
  int PwAzMin = 30;     //minimum power for which the motor doesn't stall and starts  under load
  int PwAzMax = 100;    //full power for the fastest speed
  int  PwElMin = 30;
  int PwElMax = 100;
/****************************************************************************/

ant-rot-DC-aug2022

arduino

This code is for DC motors, with soft start/stop PWM output. Use electric diagram for DC motors.

1/*  AZ/EL Antenna Rotator controller for Arduino - DC motors - PWM output
2  *  =====================================================================
3 *  Uses  EasyComm protocol for computer - Tracking Software
4 *  Manual command by means  of two rotary encoders AZ - EL
5 *  
6 *  Viorel Racoviteannu
7 *  https://www.youtube.com/channel/UCiRLZX0bV9rS04BGAyUf-fA
8  *  https://racov.ro
9 *  YO3RAK@gmail.com
10 *  
11 * I cannot take any responsibility  for missuse of this code
12 * or any kind of damage it may occur from using this  code.
13 * 
14 * dec 2020 v2 - improved serial comm stability
15 * jan 2021 -  improved near target dead-zone, for which antenna won't move
16 * apr 2021 - improved  serial comm stability
17 * jun 2021 - error proportional power for tracking movement.  Real Soft-Stop
18 * aug 2021 - faster USB update, cold switching Az/El direction,  small optimizations in the code
19 * nov 2021 - cracked the secret of Soft-Start.  It wasn't hard. There you have it
20 * aug 2022 - improved EL encoder functionality,  electric diagram modified - encoders connections
21 */
22 
23#include <Wire.h>  // Library for I2C communication
24#include <LiquidCrystal_I2C.h> // https://www.arduinolibraries.info/libraries/liquid-crystal-i2-c  (Library for LCD)
25// Wiring: SDA pin is connected to A4 and SCL pin to A5.
26//  Connect to LCD via I2C, default address 0x27 (A0-A2 not jumpered)
27LiquidCrystal_I2C  lcd(0x27, 16, 2); // address, chars, rows.
28
29// declaring custom symbol for  up/down arrow
30 byte DownArrow[8] = {
31  B00000,
32  B00100,
33  B00100,
34  B00100,
35  B10101,
36  B01110,
37  B00100,
38  B00000
39};
40 byte UpArrow[8]  = {
41  B00000,
42  B00100,
43  B01110,
44  B10101,
45  B00100,
46  B00100,
47  B00100,
48  B00000
49};
50
51/***********************************THIS IS WHERE  YOU REALY TWEAK THE ANTENNA MOVEMENT***************/
52// ANTENNA potentiometers  CALIBRATION
53  int AzMin = 1;         //begining of the potentiometer
54  int  AzMax = 1023;      //end of the potentiometer 
55  int ElMin = 1;
56  int ElMax  = 1023;
57
58// Allowed error for which antennna won't move
59  int AzErr = 8;
60  int ElErr = 4;
61
62// Angle difference where soft stop begins
63  int Amax  = 25;        //azimuth
64  int Emax = 15;        //elevation
65
66// min and  max power for motors, percents;
67  int PwAzMin = 30;     //minimum power for which  the motor doesn't stall and starts under load
68  int PwAzMax = 100;    //full  power for the fastest speed
69  int PwElMin = 30;
70  int PwElMax = 100;
71
72/***************************************************************************************************/
73
74  enum PinAssignments {
75  AzPotPin = A0,        // input pin for the azim. potentiometer
76  ElPotPin = A1,        // input pin for the elev. potentiometer    
77  AzEncoderPinA  = 2,    // Az encoder right
78  AzEncoderPinB = 4,    // Az encoder left
79  AzClearButton  = 5,    // Az encoder push
80  ElEncoderPinA = 3,    // El encoder right
81  ElEncoderPinB  = 6,    // El encoder left
82  ElClearButton = 7,    // El encoder push
83  ElPWMPin  = 9,         // out pin for elevation rotation PWM command
84  AzPWMPin = 10,        //  out pin for azimuth PWM command
85  AzRotPin = 11,        // out pin for Az rotation  direction
86  ElRotPin = 12,        // out pin for El rotation direction
87  };
88  
89// Az encoder variables
90  int AzEncBut = 1;                   // variable  to toggle with encoder push button
91  volatile boolean AzEncRot;          // if  rotation occured
92  volatile boolean AzEncUp;           // direction of rotation
93  
94// El encoder variables
95  int ElEncBut = 1;
96  volatile boolean ElEncRot;
97  volatile boolean ElEncUp;
98  
99// movement variables
100  int TruAzim = 0;      // calculated real azimuth value
101  int ComAzim = 0;      // commanded azimuth  value
102  int TruElev = 0;      // calculated real elevation value
103  int ComElev  = 0;      // commanded elevation value
104  int OldTruAzim = 0;   // to store previous  azimuth value
105  int OldComAzim = 0;
106  int OldTruElev = 0;   // to store previous  elevation value
107  int OldComElev = 0;
108  int StaAzim = 0;      // Start Azimuth  angle for motor Soft-Start
109  int StaElev = 0;      // Start Elevation angle for  motor Soft-Start
110  int PwAzStop = 0;     // calculated PWM (percent) for soft-stop
111  int PwAzStar = 0;     // calculated PWM (percent) for soft-start
112  int PwElStop  = 0;     // calculated PWM (percent) for soft-stop
113  int PwElStar = 0;     //  calculated PWM (percent) for soft-start
114  int PwAz = 0;         //calculated  power to be transmitted to motor (percents);
115  int PwEl = 0;
116  char AzDir;           // symbol for azim rot display
117  char ElDir;           // symbol for  elev. rot display
118  unsigned long NowTime;         // store the current millis()  for timing purposes
119    
120// flags for AZ, EL tolerances
121  bool AzStop =  false;
122  bool ElStop = false;
123  int ElUp = 1;                  // 1 - Elevation  Dn, 0 - Elevation STOP, 2 - Elevation Up
124  
125//averaging loop
126  const int  numReadings = 25;
127  int readIndex = 0;             // the index of the current  reading  
128  int azimuth[numReadings];      // the readings from the analog input
129  int elevation[numReadings];
130  int totalAz = 0;               // the running  total
131  int totalEl = 0;
132
133// variables for serial comm
134  String Azimuth  = "";
135  String Elevation = "";
136  String ComputerRead;
137  String ComputerWrite;
138  bool AZser = false;
139  bool ELser = false;
140  bool ANTser = false;
141
142/***************  END VARIABLE DECLARATION  ************/
143
144void setup() {
145  Serial.begin(9600);
146  Serial.setTimeout(50);           // miliseconds to wait for USB sata. Default  1000
147// Initiate the LCD:
148//  lcd.begin(16,2);               //select this  one if the arrows are not displayed correctly
149  lcd.init();
150  lcd.backlight();
151
152//  write on display name and version
153  lcd.setCursor(0, 0);           // Set the  cursor on the first column first row.(counting starts at 0!)
154  lcd.print("EasyCom  AntRotor"); // display "..."
155  lcd.setCursor(0, 1);           // Set the cursor  on the first column the second row
156  lcd.print("*Racov* Aug.2022");
157
158//creating  custom symbol for up/dwn arrow
159  lcd.createChar(1, DownArrow);
160  lcd.createChar(2,  UpArrow);
161  
162// pin declaration
163  pinMode(AzRotPin, OUTPUT);       //declaring  azim. rotation direction Pin as OUTPUT
164  pinMode(AzPWMPin, OUTPUT);       //declaring  azimuth PWM command Pin as OUTPUT
165  pinMode(ElRotPin, OUTPUT);       //declaring  elev. rotation direction Pin as OUTPUT
166  pinMode(ElPWMPin, OUTPUT);
167  pinMode(AzPotPin,  INPUT);
168  pinMode(ElPotPin, INPUT);
169  pinMode(AzEncoderPinA, INPUT);
170  pinMode(AzEncoderPinB,  INPUT);
171  pinMode(AzClearButton, INPUT);
172  pinMode(ElEncoderPinA, INPUT);
173  pinMode(ElEncoderPinB, INPUT);
174
175// Interrupt Service Routine for Az and  El encoder
176  attachInterrupt(0, doAzEnc, CHANGE);                               //  Az encoder
177  attachInterrupt(1, doElEnc, CHANGE);                               //  El Encoder
178
179/* initialization of the averaging loop
180   this is to set Az/El-command  the same value as real, not to jerk the antenna at start-up */
181  TruAzim = (map(analogRead(AzPotPin),  AzMin, AzMax, 0, 359));       // transforms potentiometer voltage into azimuth angle
182  TruElev = (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));        // transforms  potentiometer voltage into elevation angle
183
184  for (int thisReading = 0; thisReading  < numReadings; thisReading++) {
185    azimuth[thisReading] = TruAzim;
186    elevation[thisReading]  = TruElev;
187  }
188  totalAz = TruAzim * numReadings;
189  totalEl = TruElev *  numReadings;
190
191/* keep command values in range  */
192  ComAzim = constrain(TruAzim,  0, 359);
193  ComElev = constrain(TruElev, 0, 90);
194  OldTruAzim = TruAzim;
195  OldComAzim = ComAzim;
196  OldTruElev = TruElev;
197  OldComElev = TruElev;
198
199  delay(1500);                     // keep for 1.5 seconds
200// display Azim. and  Elev. values
201  lcd.setCursor(0, 0);
202  lcd.print("Azm.---" + String(char(223))  + "=Cd.---" + String(char(223)));  // char(223) is degree symbol
203  lcd.setCursor(0,  1); 
204  lcd.print("Elv. --" + String(char(223)) + "=Cd. --" + String(char(223)));
205  DisplValue(TruAzim, 4,0);
206  DisplValue(ComAzim,12,0);
207  DisplValue(TruElev,  4,1);
208  DisplValue(ComElev,12,1);
209}
210// end SETUP
211
212void loop() {
213/**************  FYI, this loop repeats 500 times per second !!! **************/
214// AZIMUTH/ELEVATION  AVERAGING LOOP
215  // subtract the oldest value
216  totalAz = totalAz - azimuth[readIndex];
217  totalEl = totalEl - elevation[readIndex];
218  // read from the sensor:
219  azimuth[readIndex]  = (map(analogRead(AzPotPin), AzMin, AzMax, 0, 359));
220  elevation[readIndex] =  (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));
221  // add the reading to the  total:
222  totalAz = totalAz + azimuth[readIndex];
223  totalEl = totalEl + elevation[readIndex];
224  // do the average
225  TruAzim = totalAz / numReadings;
226  TruElev = totalEl  / numReadings;
227/*  keep values in range
228  TruAzim = constrain(TruAzim, 0,  359);
229  TruElev = constrain(TruElev, 0, 90); */
230  // advance to the next position  in the array
231  // if we're at the end of the array, wrap around to the beginning:
232  readIndex = (readIndex + 1) % numReadings;
233
234// read the command from encoder
235  ReadAzimEncoder();
236  ReadElevEncoder();
237  
238  if (Serial.available())  {SerComm();}          // read USB data
239
240// update antenna position display  only if value change
241  if ((millis() - NowTime) > 300){              //every  0.3 seconds, not to flicker the display
242    if (OldTruAzim!=TruAzim) {
243      DisplValue(TruAzim,4,0);
244      OldTruAzim = TruAzim;
245    }
246    if (OldTruElev!=TruElev) {
247      DisplValue(TruElev,4,1);
248      OldTruElev = TruElev;
249    }
250    NowTime = millis();
251  }
252
253//  update target position display only if value change
254  if (OldComAzim != ComAzim)  {
255    DisplValue(ComAzim,12,0);
256    OldComAzim = ComAzim;
257  }
258  if (OldComElev  != ComElev) {
259    DisplValue(ComElev,12,1);
260    OldComElev = ComElev;
261  }
262
263// this is to rotate in azimuth
264  if (TruAzim == ComAzim) {                   //  if equal, stop moving
265    AzStop = true;
266    analogWrite(AzPWMPin, 0);                 //  Az motor power = 0
267    StaAzim = TruAzim;                        // this will  be the start azimuth for soft-start
268    lcd.setCursor(8, 0);
269    lcd.print("=");
270  }
271    else if ((abs(TruAzim - ComAzim)<=AzErr)&&(AzStop == false)) {  // if  in tolerance, but it wasn't an equal, rotate
272      AzimRotate();}
273    else  if (abs(TruAzim - ComAzim)>AzErr){   // if target is off tolerance
274      AzStop  = false;                         // it's not equal
275      AzimRotate();                           //  rotate
276    }
277
278// this is to rotate in elevation
279  if (TruElev == ComElev)  {                   // if equal, stop moving
280    ElStop = true;
281    analogWrite(ElPWMPin,  0);                 // El motor power = 0
282    StaElev = TruElev;                        //  this will be the start elevation for soft-start
283    lcd.setCursor(8, 1);
284    lcd.print("=");
285    ElUp = 0;                                 // flag for  elevation STOP
286  }
287  else if ((abs(TruElev - ComElev)<=ElErr)&&(ElStop ==  false)) {  // if in tolerance, but it wasn't an equal, rotate
288    ElevRotate();}
289  else if (abs(TruElev - ComElev)>ElErr){     // if target is off tolerance
290    ElStop = false;                           // it's not equal
291    ElevRotate();                             // rotate
292  }
293  
294  // this is to interpret  Az encoder x10 multiplication
295  while (AzEncBut == 10) {                    //  while toggled to x10
296    analogWrite(AzPWMPin, 0);                 // STOP antenna  rotation
297    StaAzim = TruAzim;                        // this will be the start  azimuth for soft-start
298    analogWrite(ElPWMPin, 0);
299    lcd.setCursor(8,  0);
300    lcd.print("*");
301    ReadAzimEncoder();
302    if (OldComAzim !=  ComAzim){               // update display only if numbers change
303      DisplValue(ComAzim,  12, 0);
304      OldComAzim = ComAzim;
305    }
306    delay (100);
307  }
308}  // end main LOOP
309
310//____________________________________________________
311//  ___________procedures definitions__________________
312
313void DisplValue(int x,  int y, int z) {
314  char displayString[7] = "";
315  sprintf(displayString, "%3d",  x);           // outputs a fixed lenght number (3 integer)
316  lcd.setCursor(y,  z);                        // for leading zeros '007' use "%03d"
317  lcd.print(displayString);
318  
319// ************** FOR CALIBRATION PURPOSES **************
320/*
321  Serial.print  ("Az ");
322  Serial.println (analogRead(AzPotPin));
323  Serial.print ("El ");
324  Serial.println (analogRead(ElPotPin));
325*/
326}  // end DisplValue()
327
328void  ReadAzimEncoder() {
329  if (digitalRead(AzClearButton) == LOW )  {      // if encoder  switch depressed
330    delay (250);                                  // debounce  switch
331    lcd.setCursor(0, 0);                          // refresh all the writings  on the screen
332    lcd.print("Azm.---" + String(char(223)) + "=Cd.---" + String(char(223)));
333    lcd.setCursor(0, 1); 
334    lcd.print("Elv. --" + String(char(223)) + "=Cd.  --" + String(char(223)));
335    DisplValue(TruAzim, 4,0);
336    DisplValue(ComAzim,12,0);
337    DisplValue(TruElev, 4,1);
338    DisplValue(ComElev,12,1);
339    if (AzEncBut  == 1){
340      AzEncBut = 10;                              // increment by 10 degrees
341      ComAzim = int(ComAzim/10)*10;               // ComAzim in 10deg. steps 
342    }
343    else
344      AzEncBut = 1;
345  }
346
347  if (AzEncRot){
348    delay(20);                                    // debouncing
349    if (AzEncUp)
350      ComAzim  += AzEncBut;
351    else
352      ComAzim -= AzEncBut;
353    ComAzim = ((ComAzim  + 360) % 360);            // Az Cmd between 0 and 359 deg continuous
354    AzEncRot  = false;
355  }
356} //end ReadAzimEncoder()
357
358void ReadElevEncoder() {
359  if (digitalRead(ElClearButton) == LOW )  {      // set Park Position Command Az/El
360    delay(250);                                   // debounce switch
361    ComAzim  = 260;
362    ComElev = 0;
363  }
364
365  if (ElEncRot){
366    delay(20);                                    //  debouncing
367    if (ElEncUp)
368      ComElev ++;
369    else
370      ComElev  --;
371    ComElev = constrain(ComElev, 0, 90);          // keep El Cmd value in  range
372    ElEncRot = false;
373  }
374}  // end of ReadElevEncoder()
375
376//  Interrupt Service Routine for a change to encoder pin A and B
377void doAzEnc ()
378{
379  if (digitalRead (AzEncoderPinA))
380    AzEncUp = digitalRead (AzEncoderPinB);
381  else
382    AzEncUp = !digitalRead (AzEncoderPinB);
383  AzEncRot = true;
384}  // end of doAzEnc
385
386void doElEnc ()
387{
388  if (digitalRead (ElEncoderPinA))
389    ElEncUp = digitalRead (ElEncoderPinB);
390  else
391    ElEncUp = !digitalRead  (ElEncoderPinB);
392    ElEncRot = true;
393}  // end of doElEnc
394
395void AzimRotate()  {
396    if (ComAzim > TruAzim) {                          // this to determine  direction of rotation
397// cold switching - stop motor before changing direction  - to protect mechanic and electric parts
398        if (AzDir == char(127)) {                     //  if previously rotating in the oposite direction
399          analogWrite(AzPWMPin,  0);                   // STOP the motor
400          StaAzim = TruAzim;                          //  this will be the start azimuth for soft-start
401          delay(200);                                 //  pre-switch delay
402          digitalWrite(AzRotPin, LOW);                // deactivate  rotation pin - rotate right
403          delay(200);                                 //  post-switch delay
404        }
405        else {                                        //  same directin, no Stop, no delay
406          digitalWrite(AzRotPin, LOW);                //  deactivate rotation pin - rotate right
407        }
408          AzDir = char(126);                          // "->"
409    }
410      else {
411        if (AzDir  == char(126)) {                     // if previously rotating in the oposite direction
412          analogWrite(AzPWMPin, 0);                   // STOP the motor
413          StaAzim  = TruAzim;                          // this will be the start azimuth for soft-start
414          delay(200);                                 // pre-switch delay
415          digitalWrite(AzRotPin,  HIGH);               // activate rotation pin - rotate left
416          delay(200);                                 // post-switch delay
417        }
418        else  {                                        // same directin, no Stop, no delay
419          digitalWrite(AzRotPin, HIGH);               // activate rotation pin -  rotate left
420        }
421        AzDir = char(127);                            //  "<-"
422      }
423    lcd.setCursor(8, 0);
424    lcd.print(String(AzDir));
425  // this activates azim PWM pin proportional with angle error (calculated in percents  %)
426    PwAzStop = PwAzMin + round((abs(ComAzim-TruAzim))*(PwAzMax-PwAzMin)/Amax);   //formula which outputs a power proportional with angle difference for Soft-Stop
427    PwAzStar = PwAzMin + round((abs(StaAzim-TruAzim))*(PwAzMax-PwAzMin)/Amax);   //formula  which outputs a power proportional with angle difference for Soft-Start
428    if  (PwAzStar > PwAzStop){
429         PwAz = PwAzStop;                             //choose  whichever value is smallest
430      }
431      else {PwAz = PwAzStar;}
432    if  (PwAz > PwAzMax) {PwAz = PwAzMax;}
433    analogWrite(AzPWMPin, round(2.55*PwAz));          // activate Azim drive PWM pin 
434}  // end AzimRotate()
435
436void  ElevRotate() {
437// this to determine direction of rotation
438    if (ComElev  > TruElev) {
439      if (ElUp == 1) {                                // if previously  rotating in the oposite direction
440        analogWrite(ElPWMPin, 0);                     //  STOP the motor
441        StaElev = TruElev;                            // this  will be the start elevation for soft-start
442        delay(200);                                   //  pre-switch delay
443        digitalWrite(ElRotPin, LOW);                  // deactivate  rotation pin - rotate UP
444        delay(200);                                   //  post-switch delay
445      }
446      else {                                          //  same directin, no Stop, no delay
447        digitalWrite(ElRotPin, LOW);                  //  deactivate rotation pin - rotate UP
448      }
449      lcd.setCursor(8, 1);
450      lcd.write(2);                                   // arrow up
451      ElUp  = 2;                                       // flag for elevation UP
452    }
453     else {
454      if (ElUp == 2) {                                // if previously  rotating in the oposite direction
455        analogWrite(ElPWMPin, 0);                     //  STOP the motor
456        StaElev = TruElev;                            // this  will be the start elevation for soft-start
457        delay(200);                                   //  pre-switch delay
458        digitalWrite(ElRotPin, HIGH);                 // deactivate  rotation pin - rotate UP
459        delay(200);                                   //  post-switch delay
460      }
461      else {                                          //  same directin, no Stop, no delay
462        digitalWrite(ElRotPin, HIGH);                 //  deactivate rotation pin - rotate UP
463      }
464        lcd.setCursor(8, 1);
465        lcd.write(1);                                 // arrow down
466        ElUp  = 1;                                     // flag for elevation DN
467    }
468 //  this activates azim PWM pin proportional with angle error (calculated in percents  %)
469    PwElStop = PwElMin + round((abs(ComElev-TruElev))*(PwElMax-PwElMin)/Emax);   //formula which outputs a power proportional with angle difference for Soft-Stop
470    PwElStar = PwElMin + round((abs(StaElev-TruElev))*(PwElMax-PwElMin)/Emax);   //formula  which outputs a power proportional with angle difference for Soft-Start
471    if  (PwElStar > PwElStop){
472         PwEl = PwElStop;                             //choose  whichever value is smallest
473      }
474      else {PwEl = PwElStar;}
475    if  (PwEl > PwElMax) {PwEl = PwElMax;}
476    analogWrite(ElPWMPin, round(2.55*PwEl));          // activate Elev drive PWM pin
477}  // end ElevRotate()
478
479void SerComm()  {
480  // initialize readings
481  ComputerRead = "";
482  Azimuth = "";
483  Elevation = "";
484
485  while(Serial.available()) {
486    ComputerRead= Serial.readString();  // read the incoming data as string
487//    Serial.println(ComputerRead);     //  echo the reception for testing purposes
488  }
489  
490// looking for command <AZxxx.x>
491    for (int i = 0; i <= ComputerRead.length(); i++) {
492     if ((ComputerRead.charAt(i)  == 'A')&&(ComputerRead.charAt(i+1) == 'Z')){ // if read AZ
493      for (int j =  i+2; j <= ComputerRead.length(); j++) {
494        if (isDigit(ComputerRead.charAt(j)))  {                                // if the character is number
495          Azimuth  = Azimuth + ComputerRead.charAt(j);
496        }
497        else {break;}
498      }
499     }
500    }
501    
502// looking for command <ELxxx.x>
503    for (int i =  0; i <= (ComputerRead.length()-2); i++) {
504      if ((ComputerRead.charAt(i) ==  'E')&&(ComputerRead.charAt(i+1) == 'L')){ // if read EL
505        if ((ComputerRead.charAt(i+2))  == '-') {
506          ComElev = 0;                  // if elevation negative
507          break;
508        }
509        for (int j = i+2; j <= ComputerRead.length();  j++) {
510          if (isDigit(ComputerRead.charAt(j))) {                               //  if the character is number
511            Elevation = Elevation + ComputerRead.charAt(j);
512          }
513          else {break;}
514        }
515      }
516    }
517    
518//  if <AZxx> received
519    if (Azimuth != ""){
520      ComAzim = Azimuth.toInt();
521      ComAzim = ComAzim%360;          // keeping values between limits(for trackers  with more than 360 deg. rotation)
522      }
523
524// if <ELxx> received
525    if  (Elevation != ""){
526      ComElev = Elevation.toInt();
527      if (ComElev>180)  { ComElev = 0;}
528      if (ComElev>90) {               //if received more than  90deg. (for trackers with 180deg. elevation)
529        ComElev = 180-ComElev;        //keep  below 90deg.
530        ComAzim = (ComAzim+180)%360;  //and rotate the antenna on  the back
531      }
532    }
533
534// looking for <AZ EL> interogation for antenna  position
535  for (int i = 0; i <= (ComputerRead.length()-4); i++) {
536    if ((ComputerRead.charAt(i)  == 'A')&&(ComputerRead.charAt(i+1) == 'Z')&&(ComputerRead.charAt(i+3) == 'E')&&(ComputerRead.charAt(i+4)  == 'L')){
537    // send back the antenna position <+xxx.x xx.x>
538      ComputerWrite  = "+"+String(TruAzim)+".0 "+String(TruElev)+".0";
539    //ComputerWrite =  "AZ"+String(TruAzim)+".0 EL"+String(TruElev)+".0"; //that's for Gpredict and  HamLib
540      Serial.println(ComputerWrite);
541    }
542  }
543}  // end SerComm()
544

/*  AZ/EL Antenna Rotator controller for Arduino - DC motors - PWM output
  *  =====================================================================
 *  Uses  EasyComm protocol for computer - Tracking Software
 *  Manual command by means  of two rotary encoders AZ - EL
 *  
 *  Viorel Racoviteannu
 *  https://www.youtube.com/channel/UCiRLZX0bV9rS04BGAyUf-fA
  *  https://racov.ro
 *  YO3RAK@gmail.com
 *  
 * I cannot take any responsibility  for missuse of this code
 * or any kind of damage it may occur from using this  code.
 * 
 * dec 2020 v2 - improved serial comm stability
 * jan 2021 -  improved near target dead-zone, for which antenna won't move
 * apr 2021 - improved  serial comm stability
 * jun 2021 - error proportional power for tracking movement.  Real Soft-Stop
 * aug 2021 - faster USB update, cold switching Az/El direction,  small optimizations in the code
 * nov 2021 - cracked the secret of Soft-Start.  It wasn't hard. There you have it
 * aug 2022 - improved EL encoder functionality,  electric diagram modified - encoders connections
 */
 
#include <Wire.h>  // Library for I2C communication
#include <LiquidCrystal_I2C.h> // https://www.arduinolibraries.info/libraries/liquid-crystal-i2-c  (Library for LCD)
// Wiring: SDA pin is connected to A4 and SCL pin to A5.
//  Connect to LCD via I2C, default address 0x27 (A0-A2 not jumpered)
LiquidCrystal_I2C  lcd(0x27, 16, 2); // address, chars, rows.

// declaring custom symbol for  up/down arrow
 byte DownArrow[8] = {
  B00000,
  B00100,
  B00100,
  B00100,
  B10101,
  B01110,
  B00100,
  B00000
};
 byte UpArrow[8]  = {
  B00000,
  B00100,
  B01110,
  B10101,
  B00100,
  B00100,
  B00100,
  B00000
};

/***********************************THIS IS WHERE  YOU REALY TWEAK THE ANTENNA MOVEMENT***************/
// ANTENNA potentiometers  CALIBRATION
  int AzMin = 1;         //begining of the potentiometer
  int  AzMax = 1023;      //end of the potentiometer 
  int ElMin = 1;
  int ElMax  = 1023;

// Allowed error for which antennna won't move
  int AzErr = 8;
  int ElErr = 4;

// Angle difference where soft stop begins
  int Amax  = 25;        //azimuth
  int Emax = 15;        //elevation

// min and  max power for motors, percents;
  int PwAzMin = 30;     //minimum power for which  the motor doesn't stall and starts under load
  int PwAzMax = 100;    //full  power for the fastest speed
  int PwElMin = 30;
  int PwElMax = 100;

/***************************************************************************************************/

  enum PinAssignments {
  AzPotPin = A0,        // input pin for the azim. potentiometer
  ElPotPin = A1,        // input pin for the elev. potentiometer    
  AzEncoderPinA  = 2,    // Az encoder right
  AzEncoderPinB = 4,    // Az encoder left
  AzClearButton  = 5,    // Az encoder push
  ElEncoderPinA = 3,    // El encoder right
  ElEncoderPinB  = 6,    // El encoder left
  ElClearButton = 7,    // El encoder push
  ElPWMPin  = 9,         // out pin for elevation rotation PWM command
  AzPWMPin = 10,        //  out pin for azimuth PWM command
  AzRotPin = 11,        // out pin for Az rotation  direction
  ElRotPin = 12,        // out pin for El rotation direction
  };
  
// Az encoder variables
  int AzEncBut = 1;                   // variable  to toggle with encoder push button
  volatile boolean AzEncRot;          // if  rotation occured
  volatile boolean AzEncUp;           // direction of rotation
  
// El encoder variables
  int ElEncBut = 1;
  volatile boolean ElEncRot;
  volatile boolean ElEncUp;
  
// movement variables
  int TruAzim = 0;      // calculated real azimuth value
  int ComAzim = 0;      // commanded azimuth  value
  int TruElev = 0;      // calculated real elevation value
  int ComElev  = 0;      // commanded elevation value
  int OldTruAzim = 0;   // to store previous  azimuth value
  int OldComAzim = 0;
  int OldTruElev = 0;   // to store previous  elevation value
  int OldComElev = 0;
  int StaAzim = 0;      // Start Azimuth  angle for motor Soft-Start
  int StaElev = 0;      // Start Elevation angle for  motor Soft-Start
  int PwAzStop = 0;     // calculated PWM (percent) for soft-stop
  int PwAzStar = 0;     // calculated PWM (percent) for soft-start
  int PwElStop  = 0;     // calculated PWM (percent) for soft-stop
  int PwElStar = 0;     //  calculated PWM (percent) for soft-start
  int PwAz = 0;         //calculated  power to be transmitted to motor (percents);
  int PwEl = 0;
  char AzDir;           // symbol for azim rot display
  char ElDir;           // symbol for  elev. rot display
  unsigned long NowTime;         // store the current millis()  for timing purposes
    
// flags for AZ, EL tolerances
  bool AzStop =  false;
  bool ElStop = false;
  int ElUp = 1;                  // 1 - Elevation  Dn, 0 - Elevation STOP, 2 - Elevation Up
  
//averaging loop
  const int  numReadings = 25;
  int readIndex = 0;             // the index of the current  reading  
  int azimuth[numReadings];      // the readings from the analog input
  int elevation[numReadings];
  int totalAz = 0;               // the running  total
  int totalEl = 0;

// variables for serial comm
  String Azimuth  = "";
  String Elevation = "";
  String ComputerRead;
  String ComputerWrite;
  bool AZser = false;
  bool ELser = false;
  bool ANTser = false;

/***************  END VARIABLE DECLARATION  ************/

void setup() {
  Serial.begin(9600);
  Serial.setTimeout(50);           // miliseconds to wait for USB sata. Default  1000
// Initiate the LCD:
//  lcd.begin(16,2);               //select this  one if the arrows are not displayed correctly
  lcd.init();
  lcd.backlight();

//  write on display name and version
  lcd.setCursor(0, 0);           // Set the  cursor on the first column first row.(counting starts at 0!)
  lcd.print("EasyCom  AntRotor"); // display "..."
  lcd.setCursor(0, 1);           // Set the cursor  on the first column the second row
  lcd.print("*Racov* Aug.2022");

//creating  custom symbol for up/dwn arrow
  lcd.createChar(1, DownArrow);
  lcd.createChar(2,  UpArrow);
  
// pin declaration
  pinMode(AzRotPin, OUTPUT);       //declaring  azim. rotation direction Pin as OUTPUT
  pinMode(AzPWMPin, OUTPUT);       //declaring  azimuth PWM command Pin as OUTPUT
  pinMode(ElRotPin, OUTPUT);       //declaring  elev. rotation direction Pin as OUTPUT
  pinMode(ElPWMPin, OUTPUT);
  pinMode(AzPotPin,  INPUT);
  pinMode(ElPotPin, INPUT);
  pinMode(AzEncoderPinA, INPUT);
  pinMode(AzEncoderPinB,  INPUT);
  pinMode(AzClearButton, INPUT);
  pinMode(ElEncoderPinA, INPUT);
  pinMode(ElEncoderPinB, INPUT);

// Interrupt Service Routine for Az and  El encoder
  attachInterrupt(0, doAzEnc, CHANGE);                               //  Az encoder
  attachInterrupt(1, doElEnc, CHANGE);                               //  El Encoder

/* initialization of the averaging loop
   this is to set Az/El-command  the same value as real, not to jerk the antenna at start-up */
  TruAzim = (map(analogRead(AzPotPin),  AzMin, AzMax, 0, 359));       // transforms potentiometer voltage into azimuth angle
  TruElev = (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));        // transforms  potentiometer voltage into elevation angle

  for (int thisReading = 0; thisReading  < numReadings; thisReading++) {
    azimuth[thisReading] = TruAzim;
    elevation[thisReading]  = TruElev;
  }
  totalAz = TruAzim * numReadings;
  totalEl = TruElev *  numReadings;

/* keep command values in range  */
  ComAzim = constrain(TruAzim,  0, 359);
  ComElev = constrain(TruElev, 0, 90);
  OldTruAzim = TruAzim;
  OldComAzim = ComAzim;
  OldTruElev = TruElev;
  OldComElev = TruElev;

  delay(1500);                     // keep for 1.5 seconds
// display Azim. and  Elev. values
  lcd.setCursor(0, 0);
  lcd.print("Azm.---" + String(char(223))  + "=Cd.---" + String(char(223)));  // char(223) is degree symbol
  lcd.setCursor(0,  1); 
  lcd.print("Elv. --" + String(char(223)) + "=Cd. --" + String(char(223)));
  DisplValue(TruAzim, 4,0);
  DisplValue(ComAzim,12,0);
  DisplValue(TruElev,  4,1);
  DisplValue(ComElev,12,1);
}
// end SETUP

void loop() {
/**************  FYI, this loop repeats 500 times per second !!! **************/
// AZIMUTH/ELEVATION  AVERAGING LOOP
  // subtract the oldest value
  totalAz = totalAz - azimuth[readIndex];
  totalEl = totalEl - elevation[readIndex];
  // read from the sensor:
  azimuth[readIndex]  = (map(analogRead(AzPotPin), AzMin, AzMax, 0, 359));
  elevation[readIndex] =  (map(analogRead(ElPotPin), ElMin, ElMax, 0, 90));
  // add the reading to the  total:
  totalAz = totalAz + azimuth[readIndex];
  totalEl = totalEl + elevation[readIndex];
  // do the average
  TruAzim = totalAz / numReadings;
  TruElev = totalEl  / numReadings;
/*  keep values in range
  TruAzim = constrain(TruAzim, 0,  359);
  TruElev = constrain(TruElev, 0, 90); */
  // advance to the next position  in the array
  // if we're at the end of the array, wrap around to the beginning:
  readIndex = (readIndex + 1) % numReadings;

// read the command from encoder
  ReadAzimEncoder();
  ReadElevEncoder();
  
  if (Serial.available())  {SerComm();}          // read USB data

// update antenna position display  only if value change
  if ((millis() - NowTime) > 300){              //every  0.3 seconds, not to flicker the display
    if (OldTruAzim!=TruAzim) {
      DisplValue(TruAzim,4,0);
      OldTruAzim = TruAzim;
    }
    if (OldTruElev!=TruElev) {
      DisplValue(TruElev,4,1);
      OldTruElev = TruElev;
    }
    NowTime = millis();
  }

//  update target position display only if value change
  if (OldComAzim != ComAzim)  {
    DisplValue(ComAzim,12,0);
    OldComAzim = ComAzim;
  }
  if (OldComElev  != ComElev) {
    DisplValue(ComElev,12,1);
    OldComElev = ComElev;
  }

// this is to rotate in azimuth
  if (TruAzim == ComAzim) {                   //  if equal, stop moving
    AzStop = true;
    analogWrite(AzPWMPin, 0);                 //  Az motor power = 0
    StaAzim = TruAzim;                        // this will  be the start azimuth for soft-start
    lcd.setCursor(8, 0);
    lcd.print("=");
  }
    else if ((abs(TruAzim - ComAzim)<=AzErr)&&(AzStop == false)) {  // if  in tolerance, but it wasn't an equal, rotate
      AzimRotate();}
    else  if (abs(TruAzim - ComAzim)>AzErr){   // if target is off tolerance
      AzStop  = false;                         // it's not equal
      AzimRotate();                           //  rotate
    }

// this is to rotate in elevation
  if (TruElev == ComElev)  {                   // if equal, stop moving
    ElStop = true;
    analogWrite(ElPWMPin,  0);                 // El motor power = 0
    StaElev = TruElev;                        //  this will be the start elevation for soft-start
    lcd.setCursor(8, 1);
    lcd.print("=");
    ElUp = 0;                                 // flag for  elevation STOP
  }
  else if ((abs(TruElev - ComElev)<=ElErr)&&(ElStop ==  false)) {  // if in tolerance, but it wasn't an equal, rotate
    ElevRotate();}
  else if (abs(TruElev - ComElev)>ElErr){     // if target is off tolerance
    ElStop = false;                           // it's not equal
    ElevRotate();                             // rotate
  }
  
  // this is to interpret  Az encoder x10 multiplication
  while (AzEncBut == 10) {                    //  while toggled to x10
    analogWrite(AzPWMPin, 0);                 // STOP antenna  rotation
    StaAzim = TruAzim;                        // this will be the start  azimuth for soft-start
    analogWrite(ElPWMPin, 0);
    lcd.setCursor(8,  0);
    lcd.print("*");
    ReadAzimEncoder();
    if (OldComAzim !=  ComAzim){               // update display only if numbers change
      DisplValue(ComAzim,  12, 0);
      OldComAzim = ComAzim;
    }
    delay (100);
  }
}  // end main LOOP

//____________________________________________________
//  ___________procedures definitions__________________

void DisplValue(int x,  int y, int z) {
  char displayString[7] = "";
  sprintf(displayString, "%3d",  x);           // outputs a fixed lenght number (3 integer)
  lcd.setCursor(y,  z);                        // for leading zeros '007' use "%03d"
  lcd.print(displayString);
  
// ************** FOR CALIBRATION PURPOSES **************
/*
  Serial.print  ("Az ");
  Serial.println (analogRead(AzPotPin));
  Serial.print ("El ");
  Serial.println (analogRead(ElPotPin));
*/
}  // end DisplValue()

void  ReadAzimEncoder() {
  if (digitalRead(AzClearButton) == LOW )  {      // if encoder  switch depressed
    delay (250);                                  // debounce  switch
    lcd.setCursor(0, 0);                          // refresh all the writings  on the screen
    lcd.print("Azm.---" + String(char(223)) + "=Cd.---" + String(char(223)));
    lcd.setCursor(0, 1); 
    lcd.print("Elv. --" + String(char(223)) + "=Cd.  --" + String(char(223)));
    DisplValue(TruAzim, 4,0);
    DisplValue(ComAzim,12,0);
    DisplValue(TruElev, 4,1);
    DisplValue(ComElev,12,1);
    if (AzEncBut  == 1){
      AzEncBut = 10;                              // increment by 10 degrees
      ComAzim = int(ComAzim/10)*10;               // ComAzim in 10deg. steps 
    }
    else
      AzEncBut = 1;
  }

  if (AzEncRot){
    delay(20);                                    // debouncing
    if (AzEncUp)
      ComAzim  += AzEncBut;
    else
      ComAzim -= AzEncBut;
    ComAzim = ((ComAzim  + 360) % 360);            // Az Cmd between 0 and 359 deg continuous
    AzEncRot  = false;
  }
} //end ReadAzimEncoder()

void ReadElevEncoder() {
  if (digitalRead(ElClearButton) == LOW )  {      // set Park Position Command Az/El
    delay(250);                                   // debounce switch
    ComAzim  = 260;
    ComElev = 0;
  }

  if (ElEncRot){
    delay(20);                                    //  debouncing
    if (ElEncUp)
      ComElev ++;
    else
      ComElev  --;
    ComElev = constrain(ComElev, 0, 90);          // keep El Cmd value in  range
    ElEncRot = false;
  }
}  // end of ReadElevEncoder()

//  Interrupt Service Routine for a change to encoder pin A and B
void doAzEnc ()
{
  if (digitalRead (AzEncoderPinA))
    AzEncUp = digitalRead (AzEncoderPinB);
  else
    AzEncUp = !digitalRead (AzEncoderPinB);
  AzEncRot = true;
}  // end of doAzEnc

void doElEnc ()
{
  if (digitalRead (ElEncoderPinA))
    ElEncUp = digitalRead (ElEncoderPinB);
  else
    ElEncUp = !digitalRead  (ElEncoderPinB);
    ElEncRot = true;
}  // end of doElEnc

void AzimRotate()  {
    if (ComAzim > TruAzim) {                          // this to determine  direction of rotation
// cold switching - stop motor before changing direction  - to protect mechanic and electric parts
        if (AzDir == char(127)) {                     //  if previously rotating in the oposite direction
          analogWrite(AzPWMPin,  0);                   // STOP the motor
          StaAzim = TruAzim;                          //  this will be the start azimuth for soft-start
          delay(200);                                 //  pre-switch delay
          digitalWrite(AzRotPin, LOW);                // deactivate  rotation pin - rotate right
          delay(200);                                 //  post-switch delay
        }
        else {                                        //  same directin, no Stop, no delay
          digitalWrite(AzRotPin, LOW);                //  deactivate rotation pin - rotate right
        }
          AzDir = char(126);                          // "->"
    }
      else {
        if (AzDir  == char(126)) {                     // if previously rotating in the oposite direction
          analogWrite(AzPWMPin, 0);                   // STOP the motor
          StaAzim  = TruAzim;                          // this will be the start azimuth for soft-start
          delay(200);                                 // pre-switch delay
          digitalWrite(AzRotPin,  HIGH);               // activate rotation pin - rotate left
          delay(200);                                 // post-switch delay
        }
        else  {                                        // same directin, no Stop, no delay
          digitalWrite(AzRotPin, HIGH);               // activate rotation pin -  rotate left
        }
        AzDir = char(127);                            //  "<-"
      }
    lcd.setCursor(8, 0);
    lcd.print(String(AzDir));
  // this activates azim PWM pin proportional with angle error (calculated in percents  %)
    PwAzStop = PwAzMin + round((abs(ComAzim-TruAzim))*(PwAzMax-PwAzMin)/Amax);   //formula which outputs a power proportional with angle difference for Soft-Stop
    PwAzStar = PwAzMin + round((abs(StaAzim-TruAzim))*(PwAzMax-PwAzMin)/Amax);   //formula  which outputs a power proportional with angle difference for Soft-Start
    if  (PwAzStar > PwAzStop){
         PwAz = PwAzStop;                             //choose  whichever value is smallest
      }
      else {PwAz = PwAzStar;}
    if  (PwAz > PwAzMax) {PwAz = PwAzMax;}
    analogWrite(AzPWMPin, round(2.55*PwAz));          // activate Azim drive PWM pin 
}  // end AzimRotate()

void  ElevRotate() {
// this to determine direction of rotation
    if (ComElev  > TruElev) {
      if (ElUp == 1) {                                // if previously  rotating in the oposite direction
        analogWrite(ElPWMPin, 0);                     //  STOP the motor
        StaElev = TruElev;                            // this  will be the start elevation for soft-start
        delay(200);                                   //  pre-switch delay
        digitalWrite(ElRotPin, LOW);                  // deactivate  rotation pin - rotate UP
        delay(200);                                   //  post-switch delay
      }
      else {                                          //  same directin, no Stop, no delay
        digitalWrite(ElRotPin, LOW);                  //  deactivate rotation pin - rotate UP
      }
      lcd.setCursor(8, 1);
      lcd.write(2);                                   // arrow up
      ElUp  = 2;                                       // flag for elevation UP
    }
     else {
      if (ElUp == 2) {                                // if previously  rotating in the oposite direction
        analogWrite(ElPWMPin, 0);                     //  STOP the motor
        StaElev = TruElev;                            // this  will be the start elevation for soft-start
        delay(200);                                   //  pre-switch delay
        digitalWrite(ElRotPin, HIGH);                 // deactivate  rotation pin - rotate UP
        delay(200);                                   //  post-switch delay
      }
      else {                                          //  same directin, no Stop, no delay
        digitalWrite(ElRotPin, HIGH);                 //  deactivate rotation pin - rotate UP
      }
        lcd.setCursor(8, 1);
        lcd.write(1);                                 // arrow down
        ElUp  = 1;                                     // flag for elevation DN
    }
 //  this activates azim PWM pin proportional with angle error (calculated in percents  %)
    PwElStop = PwElMin + round((abs(ComElev-TruElev))*(PwElMax-PwElMin)/Emax);   //formula which outputs a power proportional with angle difference for Soft-Stop
    PwElStar = PwElMin + round((abs(StaElev-TruElev))*(PwElMax-PwElMin)/Emax);   //formula  which outputs a power proportional with angle difference for Soft-Start
    if  (PwElStar > PwElStop){
         PwEl = PwElStop;                             //choose  whichever value is smallest
      }
      else {PwEl = PwElStar;}
    if  (PwEl > PwElMax) {PwEl = PwElMax;}
    analogWrite(ElPWMPin, round(2.55*PwEl));          // activate Elev drive PWM pin
}  // end ElevRotate()

void SerComm()  {
  // initialize readings
  ComputerRead = "";
  Azimuth = "";
  Elevation = "";

  while(Serial.available()) {
    ComputerRead= Serial.readString();  // read the incoming data as string
//    Serial.println(ComputerRead);     //  echo the reception for testing purposes
  }
  
// looking for command <AZxxx.x>
    for (int i = 0; i <= ComputerRead.length(); i++) {
     if ((ComputerRead.charAt(i)  == 'A')&&(ComputerRead.charAt(i+1) == 'Z')){ // if read AZ
      for (int j =  i+2; j <= ComputerRead.length(); j++) {
        if (isDigit(ComputerRead.charAt(j)))  {                                // if the character is number
          Azimuth  = Azimuth + ComputerRead.charAt(j);
        }
        else {break;}
      }
     }
    }
    
// looking for command <ELxxx.x>
    for (int i =  0; i <= (ComputerRead.length()-2); i++) {
      if ((ComputerRead.charAt(i) ==  'E')&&(ComputerRead.charAt(i+1) == 'L')){ // if read EL
        if ((ComputerRead.charAt(i+2))  == '-') {
          ComElev = 0;                  // if elevation negative
          break;
        }
        for (int j = i+2; j <= ComputerRead.length();  j++) {
          if (isDigit(ComputerRead.charAt(j))) {                               //  if the character is number
            Elevation = Elevation + ComputerRead.charAt(j);
          }
          else {break;}
        }
      }
    }
    
//  if <AZxx> received
    if (Azimuth != ""){
      ComAzim = Azimuth.toInt();
      ComAzim = ComAzim%360;          // keeping values between limits(for trackers  with more than 360 deg. rotation)
      }

// if <ELxx> received
    if  (Elevation != ""){
      ComElev = Elevation.toInt();
      if (ComElev>180)  { ComElev = 0;}
      if (ComElev>90) {               //if received more than  90deg. (for trackers with 180deg. elevation)
        ComElev = 180-ComElev;        //keep  below 90deg.
        ComAzim = (ComAzim+180)%360;  //and rotate the antenna on  the back
      }
    }

// looking for <AZ EL> interogation for antenna  position
  for (int i = 0; i <= (ComputerRead.length()-4); i++) {
    if ((ComputerRead.charAt(i)  == 'A')&&(ComputerRead.charAt(i+1) == 'Z')&&(ComputerRead.charAt(i+3) == 'E')&&(ComputerRead.charAt(i+4)  == 'L')){
    // send back the antenna position <+xxx.x xx.x>
      ComputerWrite  = "+"+String(TruAzim)+".0 "+String(TruElev)+".0";
    //ComputerWrite =  "AZ"+String(TruAzim)+".0 EL"+String(TruElev)+".0"; //that's for Gpredict and  HamLib
      Serial.println(ComputerWrite);
    }
  }
}  // end SerComm()

Downloadable files

Electric Diagram for AC motors

Make sure you use this diagram with the code for AC motors. Offers dry contacts (ON/OFF). It can be easily interfaced with commercial rotators.

Electric Diagram for AC motors

Electric Diagram for DC motors

Make sure you use this diagram with the code for DC motors. PWM output, Smoother antenna movement

Electric Diagram for DC motors

Make sure you use this diagram with the code for DC motors. PWM output, Smoother antenna movement

Electric Diagram for DC motors

Electric Diagram for AC motors

Make sure you use this diagram with the code for AC motors. Offers dry contacts (ON/OFF). It can be easily interfaced with commercial rotators.

Electric Diagram for AC motors

Comments

Only logged in users can leave comments

LU3FFJ

a year ago

Unfortunately, the images with the electrical diagrams are not visible.

pa2j

2 years ago

HI, i am trying to modify the code for old AZ-Rotators like G400 running from South to South ( 180-180) over North 360/0 in midle of Potmeter Also added "R" and "L" for serial command from PC ( using Rotocraft 1.0) will send you an Email with the details 73 Jasper PA2J

Anonymous user

2 years ago

23/07/22 Bonjour,me lançant sur un nouveau défit concernant le stracking (ISS ou Autre satellites),je me suis lancé sur ce projet avec Arduino + relais pour piloter 2 moteurs alternatifs(Yaesu G450+verrin parabole) pour effectuer une poursuite sat.J'ai déjà testé le programme inclus ci-dessus mais apparement ,Il est éronné Msg d'erreur : LiquidCrystal_I2C.h: No such file or directory #include <LiquidCrystal_I2C.h> // https://www.arduinolibraries.info/libraries/liquid-crystal-i2-c (Library for LCD) Et ne maitrisant pas du tout le language Arduino j'aurai besoin d'aide SVP Cordialement Thierry

viorelracoviteanu

2 years ago

Bonjour Thierry, Donne moi s'il te plaît, un email, pour approfondir le sujet. YO3RAK@GMAIL.COM

Anonymous user

2 years ago

Can two stepper motors be used for this

viorelracoviteanu

2 years ago

Hi Preston, Sure, steppers are great and more precise. There are modules that interface easily with Arduino. I am not very familiar with steppers, the code must be changed a little, but sure it can be a great project. Give me an email if you want more information, because this platform doesn't inform me of new comments, dunno why.

Anonymous user

2 years ago

Trying to run the code without success so far I found a mistake in the Circuit diagram- The SDA pin should be connected to the A4 And the SCL pin should be connected to the A5 And not as shown in the Circuit diagram

Anonymous user

2 years ago

There are several different libraries named LiquidCrystal_I2C, the problems related to the LCD in the previous comments are caused by using the wrong library. It would really help if you specified in the code where the particular library you used came from.

Anonymous user

2 years ago

I am building a rotor with automotive window regulator motors and I have built the interface to work with your application. It works wonderfully. Congratulations. On the other hand, with Orbitron, I have a problem: With the MyDDE driver, the application works fine, but of course it does not control my TX. On the other hand with SpidAlfa or WispDDE, by configuring easycom, I only receive inconsistent data. If I set up with other rotors, it doesn't spin. I do not know what to do. Do you have an idea ? Thank you

viorelracoviteanu

2 years ago

Hi Paulo. I'm sorry for the late answer, this platform doesn't inform me of new comments. You're talking about SpidAlfa or WispDDE for Orbitron, I supose. These are different protocols and will not work with this controller. By TX you mean radio TX? If you want both antenna rotator and radio control, you can use WXtrack, for example, or other similar software. I use PstRotator and it's excellent (but it's not free). Please send me an email (you'll find my address here in the comments), to discuss in more detail.

Anonymous user

2 years ago

I would like to drive a DC Servomotor system with a +/- 10 Vdc Rate Error voltage instead of ON / OFF Relay commands. Can you adapt this to do that? Is the output based on Error Angle?

viorelracoviteanu

2 years ago

Hey grblake, Yes, it's based on error angle. I don't really understand what type of motor you have. Please send me an email, and I'm sure we can sort it out.

Anonymous user

2 years ago

I cannot find where to find your email? let me know how or send me an email. Thank You. I am using a 90 Vdc Servo motor with Field Windings. I have to energize the motor field to create the magnetism before you can apply the drive to the armature. it is much higher power. I am using JUNUS Servo Amplifiers from Copley Controls.

Anonymous user

2 years ago

When I try to compile the code in Arduino IDE I receive this message: Arduino: 1.8.13 (Windows 10), Board: "Arduino Mega or Mega 2560, ATmega2560 (Mega 2560)" C:\\Users\\georg\\OneDrive\\Documents\\Ham Radio\\Pelco\\arduino_uno_antenna_rotator___april_2021_GRB\\arduino_uno_antenna_rotator___april_2021_GRB.ino: In function 'void setup()': arduino_uno_antenna_rotator___april_2021_GRB:124:7: error: 'class LiquidCrystal_I2C' has no member named 'init' lcd.init(); ^~~~ Multiple libraries were found for "LiquidCrystal.h" Used: C:\\Users\\georg\\Documents\\Arduino\\libraries\\LiquidCrystal Not used: C:\\Program Files (x86)\\Arduino\\libraries\\LiquidCrystal exit status 1 'class LiquidCrystal_I2C' has no member named 'init' This report would have more information with "Show verbose output during compilation" option enabled in File -> Preferences.

Anonymous user

2 years ago

Hi, Good afternoon. Did you get a solution to your query? I have the same issue. I look forward to hearing from you. Angus

Anonymous user

2 years ago

Greetings. I am working on a version with Analog rate Error output from a DAC in both axes. This is the boards I am using: https://visgence.com/hardware/powerdacshield/ The Servo Amplifiers can accept both PWM / Direction and +/- 10 Vdc Rate Error Analog voltages. I am partial to Analog vs. Digital commands, but I will use them if I have to. I am using Potentiometer feedback for position. I like the display and the manual function. Is there a JOG function? I would like the LCD to receive Serial Rx data vs. SCL / SDA data. I have LCD's with a Serial adapter board. Can you help? Thanks.

Anonymous user

2 years ago

Oh yeah: I also want to use Potentiometer feedback vs. Encoder.

Anonymous user

2 years ago

Hola buenas tardes, seria posible usar dos encoder lpd3806 en lugar de los potenciometros para sensar la posicion de la antena, deberia modificarse el codigo, pero seria mucho mas preciso o me equivoco. Hello good afternoon, it would be possible to use two lpd3806 encoders instead of the potentiometers to sense the position of the antenna, the code should be modified, but it would be much more precise or am I wrong.

viorelracoviteanu

2 years ago

Hola Gonza. It is very complicated to use this encoder as a position sensor, for this project, of course. The code must be modified and, because this is an incremental encoder, it doesn't have a default position, like a potentiometer. So every time the controller is powered up, the antenna must perform a full turn, to discover its limits. So yeah, it's a very good device, but very hard to use with this project. It's not worth the effort. The precision you get from the potentiometers is more than enough. Send me an email, if you want to discuss more.

Anonymous user

2 years ago

Okey muchas gracias por tu respuesta, voy a modificar mis sensores, voy a poner dos potenciometros en lugar de los encoders, para probar luego te comento mis resultados no veo tu mail por ningun sitio el mio es lu5fow@gmail.com desde ya muchas gracias muy amable de tu parte por responderme. Ok, thank you very much for your answer, I am going to modify my sensors, I am going to put two potentiometers instead of the encoders, to test later I will tell you my results I do not see your email anywhere mine is lu5fow@gmail.com thank you very much very kind of you to answer me.

Anonymous user

2 years ago

Hello Viorel, I used WXtrack and it worked, that's when I discovered the update in WXtrack that was 5 seconds away, in the orbitron as I had changed to 1 second it doesn't work, because it locks the reading pots, so i left it in the orbitron every 5 seconds and it worked, in 1 second it overloads the readings of the arduino.

viorelracoviteanu

2 years ago

Hello, Please check again the new code I update recently. It works better and prevents the overload that you mentioned. If you have any problems, let me know.

Anonymous user

2 years ago

Hi Viorel, Wonderful project, thank you very much, in the first version it already worked well, although the arrow above appears four dashes, now with this update it was fantastic. Thanks again.

Anonymous user

2 years ago

ok I found the problem This line should be corrected: // Initiate the LCD: lcd.init (); This should be the correct sentence and not as in the original software lcd.backlight (); that's it ENJOY Yoram

viorelracoviteanu

2 years ago

Hello Yoram. Lcd.init and backlight are two different things and should both be used in the right place. If the LCD pins were switched in the diagram, I am very sorry. I am very glad it works for you. All the best 👍

Anonymous user

2 years ago

I'm glad the drawing has been corrected - But the software is not yet Please note that the sentence in line 126 Show like this: 125 // Initiate the LCD: 126 // lcd.init(); This causes the display to not work for me. Should be as follows: 125 // Initiate the LCD: 126 lcd.init(); Best Yoram

viorelracoviteanu

2 years ago

Thanks for pointing me the drawing error. I know what you mean with the LCD. I guess it depends on the LCD manufacturers. Indeed, the lcd.init() should be used right there, but the reason it was commented was that sometimes the custom characters (arrow up and down) were not displayed correctly. It gave me head aches, I goolgled and find another mean to initialize the display. This is why I used 93 lcd.begin(16,2); It worked better with my display. I'm not a specialist in Arduino, I have good knowledge of electronics and average knowledge of programming, so this whole code is pretty much adapted from bits of information I found here and there. If you and anyone else could find just even a small piece of useful inspiration in my work, I am more than happy I could help, because I also found useful inspiration in others work, when I was in need. Thank you very much for your input. Sincerely, Viorel

Anonymous user

2 years ago

hello, wonderful Project, managed to create a good rotator base, I was wondering if it is possible to replace the regular motors with Steppers? I am good with crafting but bad when it comes to programming^^

viorelracoviteanu

2 years ago

Hello Nubi. If I had steppers in stock by the time I made this project, it would came out nicely for steppers. Odds were I had DC motors. That's why I recommend using DC motors. Yes, you could use steppers if you must, but you have two options: 1. Use the code for DC motors and the module https://www.pololu.com/product/1182 like in the project described here https://how2electronics.com/control-stepper-motor-with-a4988-driver-arduino/ The advantage is that it works right away, without modifications. The disadvantage is that you can't make use of the soft start/stop feature. This is a tragedy, in my opinion. 2. Use the code for DC motors for the start, and modify it in order to work properly with steppers and this module https://www.aliexpress.com/i/1699294831.html Please use the email if you want more details. As I said before, this platform doesn't inform me of new comments.

Anonymous user

2 years ago

Hello, dear. Congratulations on your assembly. I have a problem with the azimuth setting. It takes a long time to adjust to the angle requested. 73. Ed

viorelracoviteanu

2 years ago

Hello Ed. Please describe in more detail the problem you encounter. You'll find my email address here in the comments, if you want more information. 73!

Anonymous user

2 years ago

Hello my friend, a wonderful project! I got a little problem with the replica, but that doesn't bother me. There is no arrow for up or down, but 4 horizontal lines instead. Do you have any idea? I noticed something else. Orbitron sends data via the interface, but there are no changes to the AZ or EL angles but it works great with Satellite Tracking WXtrack! What is wrong ! Thank you

viorelracoviteanu

2 years ago

Hey Cool, Please check again the new code I update recently. If you have any problems, let me know.

Anonymous user

2 years ago

Good afternoon. I really liked your project. The firmware was successful. Everything works. Please tell me where to fix it in the firmware. By elevation, 0 degrees is 0 volts, and 360 degrees is 5 volts. In your firmware, 0 degrees is 0 volts, and 90 degrees is 5 volts. I need to apply this to the finished design.

Anonymous user

2 years ago

Can the same code work with arduino nano ?

viorelracoviteanu

2 years ago

Hey George, Yes it can. Same pins, absolutely no changes. Please use the email if you want more details. As I said before, this platform doesn't inform me of new comments.

Anonymous user

2 years ago

Buon giorno, Vorrei realizzare questo progetto anche se al momento mi interessa solo il controllo azimutale, però ho provato a verificare il software sulla scheda Arduino e mi da errore di compilazione. Dove posso ottenere i componenti?

Anonymous user

2 years ago

the code is not working can't get to load up stops at r4 and can't find the liberary for the LCD whet to do. sm3uqo

viorelracoviteanu

2 years ago

Hey sm3uqo, Please check again the new code I update recently. Here is the LCD library that I used https://github.com/fdebrabander/Arduino-LiquidCrystal-I2C-library If you have any problems, let me know.

Anonymous user

2 years ago

Helo. I have 2 Orbit 360 antenna rotators that use DC motors with reversible leads to control direction. 1Kohm pot is used for direction feedback.in the stock configuration, a resistor in the controller is adjusted to the direction the antenna is to be pointed to on a paper direction indicator. The resister generates a voltage that is fed into one of the inputs on a 741 op amp. a resistor in the rotator also generates a voltage based on where the antenna is pointed. is there any way to use this software without the encoders?

viorelracoviteanu

2 years ago

Hey aa5ao, Short answer ,YES. Just connect the corresponding pins to GND, to avoid random readings. (D2,3,4,5,6) I'm sorry for the very late answer. As I said before, this platform doesn't inform me of new comments. I only now saw your post. Please use the email, I'll reply much faster.

ecattin

2 years ago

Hello if i want to remove the elevation part and keep only the azimuth part what would the arduino sketch be? thank you

viorelracoviteanu

2 years ago

Hello Ecattin. You can use it exactly as it is, no problem. You disregard completely the elevation part in hardware, don't put an encoder for elevation, no potentiometer for reading the antenna elevation (just put the pin to GND). You will get 0 degrees reading on the display. That's all. Fore more information, please email me. yo3rak gmail.com I answer faster to this one. All the best. Racov

Anonymous user

2 years ago

Dear Viuear i am building your rotator antenna project could you tell me the encoder pins mine has all 5 pins in a row. clk, dt, sw, +, gnd. many thank's (IW5DEJ) Paolo Danesi

viorelracoviteanu

2 years ago

Hi Paolo. Please send me a photo of the encoder at yo3rak-gmail.com

viorelracoviteanu

2 years ago

I got it. I'll get back to you as soon as possible.

Anonymous user

2 years ago

code is not working

viorelracoviteanu

2 years ago

Of course it is working. What issues did you encounter?

Anonymous user

2 years ago

Hi I have a problem with the Elevation encoder. It takes two steps every clic on the encoder but Azimuth works fine. I have swithed the encoders between azim/elev and tried another arduino but the problem is the same. Everything else works fine. Is it something in the program ? // Otto

viorelracoviteanu

2 years ago

Hello Otto. Yes, I believe it has something to do with the program. The azimuth encoder uses a much more precise code, which uses interrupts. For the elevation, there were no more interrupts available, so the debouncing is not very accurate. That's why sometimes, some encoders jump two steps. I, sometimes, happen to jump back on elevation. Unfortunately, I was not able to find a better solution. Since I plan on using it mainly with computer command, it was not that big issue for me. All the best, Racov

Anonymous user

3 years ago

viorelracoviteanu

2 years ago

Bonjour Thierry, Donne moi s'il te plaît, un email, pour approfondir le sujet. YO3RAK@GMAIL.COM

Anonymous user

3 years ago

viorelracoviteanu

2 years ago

Anonymous user

2 years ago

nubi435

3 years ago

viorelracoviteanu

2 years ago

Anonymous user

3 years ago

Can the same code work with arduino nano ?

viorelracoviteanu

2 years ago

Hey George, Yes it can. Same pins, absolutely no changes. Please use the email if you want more details. As I said before, this platform doesn't inform me of new comments.

Anonymous user

3 years ago

viorelracoviteanu

2 years ago

Anonymous user

4 years ago

Can two stepper motors be used for this

viorelracoviteanu

2 years ago

grblake

4 years ago

angusgm6agc

2 years ago

Hi, Good afternoon. Did you get a solution to your query? I have the same issue. I look forward to hearing from you. Angus

grblake

4 years ago

grblake

4 years ago

Oh yeah: I also want to use Potentiometer feedback vs. Encoder.

grblake

4 years ago

I would like to drive a DC Servomotor system with a +/- 10 Vdc Rate Error voltage instead of ON / OFF Relay commands. Can you adapt this to do that? Is the output based on Error Angle?

grblake

2 years ago

viorelracoviteanu

2 years ago

Hey grblake, Yes, it's based on error angle. I don't really understand what type of motor you have. Please send me an email, and I'm sure we can sort it out.

rw3qsz

4 years ago

jeanopaulo

4 years ago

viorelracoviteanu

2 years ago

Anonymous user

4 years ago

Hello, dear. Congratulations on your assembly. I have a problem with the azimuth setting. It takes a long time to adjust to the angle requested. 73. Ed

viorelracoviteanu

2 years ago

Hello Ed. Please describe in more detail the problem you encounter. You'll find my email address here in the comments, if you want more information. 73!

Anonymous user

4 years ago

Dear Viuear i am building your rotator antenna project could you tell me the encoder pins mine has all 5 pins in a row. clk, dt, sw, +, gnd. many thank's (IW5DEJ) Paolo Danesi

viorelracoviteanu

2 years ago

I got it. I'll get back to you as soon as possible.

viorelracoviteanu

2 years ago

Hi Paolo. Please send me a photo of the encoder at yo3rak-gmail.com

Anonymous user

4 years ago

the code is not working can't get to load up stops at r4 and can't find the liberary for the LCD whet to do. sm3uqo

viorelracoviteanu

2 years ago

eletronicadopardalivai

4 years ago

viorelracoviteanu

2 years ago

Hello, Please check again the new code I update recently. It works better and prevents the overload that you mentioned. If you have any problems, let me know.

eletronicadopardalivai

2 years ago

Hi Viorel, Wonderful project, thank you very much, in the first version it already worked well, although the arrow above appears four dashes, now with this update it was fantastic. Thanks again.

Anonymous user

4 years ago

viorelracoviteanu

2 years ago

Hey Cool, Please check again the new code I update recently. If you have any problems, let me know.

Anonymous user

4 years ago

ecattin

4 years ago

Hello if i want to remove the elevation part and keep only the azimuth part what would the arduino sketch be? thank you

viorelracoviteanu

2 years ago

Anonymous user

4 years ago

viorelracoviteanu

2 years ago

Anonymous user

5 years ago

Anonymous user

5 years ago

viorelracoviteanu

2 years ago

Anonymous user

5 years ago

ok I found the problem This line should be corrected: // Initiate the LCD: lcd.init (); This should be the correct sentence and not as in the original software lcd.backlight (); that's it ENJOY Yoram

viorelracoviteanu

2 years ago

Anonymous user

5 years ago

Anonymous user

5 years ago

Felicitari ! fain proiect

Anonymous user

5 years ago

code is not working

viorelracoviteanu

2 years ago

Of course it is working. What issues did you encounter?

viorelracoviteanu

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