4ws steering nano controller for 2ch radio RC models

1/* 
2I used an inexpensive nano board v3 ATmega 328p 
3the pins used  are: 
4VIN(+)and GND(-) 
5you can feed the power from your bec (5-9 volt) 
6D7  throttle signal input. 
7D8 front steering input signal. 
8D10 rear steering  signal output.
9D4 blinking dx leds
10D5 blinking sx leds
11-----------------------------------------
12basic  setup instructions: 
13first you must obtain the best mechanical setup from your  front and rear servos and linkage.
14best without subtrims or radio adjustements.  
15the values you find default should make the controller work quite right away.
16however  if you want to be sure about what are your real radio signal inputs, or if they  are reversed check them before starting this sketch. 
17create a new tab and check  your input signals with this program (7 for steering - 8 for throttle gas)
18
19int  rxpulse;
20void setup () {
21Serial.begin (9600);
22}
23void loop () {
24rxpulse  = pulseIn (7, HIGH); // - 7 to know  front steering signal values, change to 8 and  load again to check  throttle values in serial monitor
25Serial.println (rxpulse);
26
27you  can read the values in the serial monitor by turning the steering wheel of the radio  control or moving the throttle.
28write the values obtained ann fill  the first  define part of the controller setup, replace the default ones with yours custom  values.
29-------------------------------------------------- ------
30the user  driving setup consists of 2 main functions: 
31first you can choose how much throttle  allow at low speed 
32before the width of the rear servo starts to close (Speedlimit  function).
33
34the second function allows you to determine rear servo width at  maximum throttle (Max_gain).
35you can choose to close it completely to 2ws or  keep 4ws available even at maximum speed
36
37the other functions are: 
38tolerance  give stepper movement to servo (set it to zero).
39Blinkpoint allow steering travel  before led start to blink. 
40
41-----------
42somethimes it can happen that  you exceed with the values the direction result inverted, be careful to find the  best suitable values for your model.
43to get the servo reverse you just have to  exchange the Postsx Postdx rear steering values and put a sign (-) in front of the  Max_gain value
44there is a relationship between Slowlimit and Max_gain, it can  happen that if you lower one you will have to raise the other
45however I am sure  that it will take you little time to understand how controller works
46*/
47
48//-----------  signal setup -------------------------------------
49#define Neutral 1500 // --  default 1500//minimum throttle forward signal or neutral position
50#define Maxspeed  2000 // -- default 2000//maximum throttle forward signal 
51#define Antsx 1000  // -- default 1000//in front servo signal sx
52#define Antdx 2000 // -- default  2000//in front servo signal dx
53#define Streight 1500 //-- default 1500//neutral  signal steering centered position for blinking arrow light (if seering center is  not zero: add or subtract half of Center value)
54
55#define Postsx 1000 //--  default 1000//out rear servo sx end point (if inverted with postdx it reverse)
56#define  Postdx 2000 //-- default 2000//out rear servo dx endpoint (if inverted with postsx  it reverse)
57#define Center 0 //-- default 0//add or subtract your value to center  steering (+- 50 or more)
58 
59//--------- user driving setup ------------------------------
60  
61#define Max_gain 400 //-- default 400//gain steering reduction width at max  throttle (if work reverse add (-) before value)
62#define Slowlimit 1600 //-- default  1600//slow forward percentage without endpoint correction
63#define Blinkpoint  300 //-- default 300//steering value where led start to blink, small values  start  led blink close near to center
64#define Tolerance 0 //-- default 0//add/remove  stepper servo steering movement
65
66//----------------------------
67#include  <Servo.h>
68Servo myservo; 
69#define N_STST  7 //--default7//if servo response  is slow low this value to 4 values less 4 may give servo vibration            
70#define  N_STGAS 7 //--default7//if servo response is slow low this value to 4 values less  4 may give servo vibration 
71unsigned int stSt[ N_STST ];  
72unsigned int stGas[  N_STGAS ];       
73long toStSt = 0;           
74long toStGas = 0;         
75int  inSt = 0;                                         
76int inGas = 0;           
77unsigned  int Rxpulse;
78unsigned int Gaspulse ;
79unsigned int Gain;
80unsigned int NewPos,  OldPos;
81int led1 = 4;//--led dx
82int led2 = 5;//-- led sx
83void setup() {
84for  ( int i=0; i<N_STST; i++ ) stSt[ i ] = 0;
85for ( int i=0; i<N_STGAS; i++ ) stGas[  i ] = 0;
86myservo.attach(10); //--  rear servo signal out pin 10
87pinMode(8,  INPUT); //--  front servo signal in pin 8
88pinMode(7, INPUT); //-- throttle signal  in pin 7
89pinMode(led1, OUTPUT);
90pinMode(led2, OUTPUT);
91}
92void loop(){
93
94  
95    noInterrupts();   
96Rxpulse = pulseIn(8, HIGH);
97Gaspulse = pulseIn(7,  HIGH);
98     interrupts();     
99delay(5);
100if (Gaspulse > Slowlimit) { //--  default >// if your throttle signal is reverse must change "<" 
101Gain = map(Gaspulse,  Slowlimit, Maxspeed, 0, Max_gain );
102NewPos = map(Rxpulse, Antsx, Antdx, (Postsx  + Gain), (Postdx - Gain));
103  }
104else {
105NewPos = map(Rxpulse, Antsx, Antdx,  Postsx, Postdx);
106  }
107if (abs(NewPos - OldPos)> Tolerance) {
108OldPos = NewPos;
109myservo.write(NewPos  + Center);
110
111if (OldPos > Streight+Blinkpoint) digitalWrite(led1, (millis()  / 100) % 2); //--default 100 is led blink speed 
112              
113 else   digitalWrite(led1,  LOW);  
114if (OldPos < Streight-Blinkpoint) digitalWrite(led2, (millis() / 100)  % 2); //--default 100 is led blink speed 
115               
116  else  digitalWrite(led2,  LOW);  
117
118}
119}

1/* 
2I used an inexpensive nano board v3 ATmega 328p 
3the pins used
4  are: 
5VIN(+)and GND(-) 
6you can feed the power from your bec (5-9 volt) 
7D7
8  throttle signal input. 
9D8 front steering input signal. 
10D10 rear steering
11  signal output.
12D4 blinking dx leds
13D5 blinking sx leds
14-----------------------------------------
15basic
16  setup instructions: 
17first you must obtain the best mechanical setup from your
18  front and rear servos and linkage.
19best without subtrims or radio adjustements.
20  
21the values you find default should make the controller work quite right away.
22however
23  if you want to be sure about what are your real radio signal inputs, or if they
24  are reversed check them before starting this sketch. 
25create a new tab and check
26  your input signals with this program (7 for steering - 8 for throttle gas)
27
28int
29  rxpulse;
30void setup () {
31Serial.begin (9600);
32}
33void loop () {
34rxpulse
35  = pulseIn (7, HIGH); // - 7 to know  front steering signal values, change to 8 and
36  load again to check  throttle values in serial monitor
37Serial.println (rxpulse);
38
39you
40  can read the values in the serial monitor by turning the steering wheel of the radio
41  control or moving the throttle.
42write the values obtained ann fill  the first
43  define part of the controller setup, replace the default ones with yours custom
44  values.
45-------------------------------------------------- ------
46the user
47  driving setup consists of 2 main functions: 
48first you can choose how much throttle
49  allow at low speed 
50before the width of the rear servo starts to close (Speedlimit
51  function).
52
53the second function allows you to determine rear servo width at
54  maximum throttle (Max_gain).
55you can choose to close it completely to 2ws or
56  keep 4ws available even at maximum speed
57
58the other functions are: 
59tolerance
60  give stepper movement to servo (set it to zero).
61Blinkpoint allow steering travel
62  before led start to blink. 
63
64-----------
65somethimes it can happen that
66  you exceed with the values the direction result inverted, be careful to find the
67  best suitable values for your model.
68to get the servo reverse you just have to
69  exchange the Postsx Postdx rear steering values and put a sign (-) in front of the
70  Max_gain value
71there is a relationship between Slowlimit and Max_gain, it can
72  happen that if you lower one you will have to raise the other
73however I am sure
74  that it will take you little time to understand how controller works
75*/
76
77//-----------
78  signal setup -------------------------------------
79#define Neutral 1500 // --
80  default 1500//minimum throttle forward signal or neutral position
81#define Maxspeed
82  2000 // -- default 2000//maximum throttle forward signal 
83#define Antsx 1000
84  // -- default 1000//in front servo signal sx
85#define Antdx 2000 // -- default
86  2000//in front servo signal dx
87#define Streight 1500 //-- default 1500//neutral
88  signal steering centered position for blinking arrow light (if seering center is
89  not zero: add or subtract half of Center value)
90
91#define Postsx 1000 //--
92  default 1000//out rear servo sx end point (if inverted with postdx it reverse)
93#define
94  Postdx 2000 //-- default 2000//out rear servo dx endpoint (if inverted with postsx
95  it reverse)
96#define Center 0 //-- default 0//add or subtract your value to center
97  steering (+- 50 or more)
98 
99//--------- user driving setup ------------------------------
100
101  
102#define Max_gain 400 //-- default 400//gain steering reduction width at max
103  throttle (if work reverse add (-) before value)
104#define Slowlimit 1600 //-- default
105  1600//slow forward percentage without endpoint correction
106#define Blinkpoint
107  300 //-- default 300//steering value where led start to blink, small values  start
108  led blink close near to center
109#define Tolerance 0 //-- default 0//add/remove
110  stepper servo steering movement
111
112//----------------------------
113#include
114  <Servo.h>
115Servo myservo; 
116#define N_STST  7 //--default7//if servo response
117  is slow low this value to 4 values less 4 may give servo vibration            
118#define
119  N_STGAS 7 //--default7//if servo response is slow low this value to 4 values less
120  4 may give servo vibration 
121unsigned int stSt[ N_STST ];  
122unsigned int stGas[
123  N_STGAS ];       
124long toStSt = 0;           
125long toStGas = 0;         
126int
127  inSt = 0;                                         
128int inGas = 0;           
129unsigned
130  int Rxpulse;
131unsigned int Gaspulse ;
132unsigned int Gain;
133unsigned int NewPos,
134  OldPos;
135int led1 = 4;//--led dx
136int led2 = 5;//-- led sx
137void setup() {
138for
139  ( int i=0; i<N_STST; i++ ) stSt[ i ] = 0;
140for ( int i=0; i<N_STGAS; i++ ) stGas[
141  i ] = 0;
142myservo.attach(10); //--  rear servo signal out pin 10
143pinMode(8,
144  INPUT); //--  front servo signal in pin 8
145pinMode(7, INPUT); //-- throttle signal
146  in pin 7
147pinMode(led1, OUTPUT);
148pinMode(led2, OUTPUT);
149}
150void loop(){
151
152
153  
154    noInterrupts();   
155Rxpulse = pulseIn(8, HIGH);
156Gaspulse = pulseIn(7,
157  HIGH);
158     interrupts();     
159delay(5);
160if (Gaspulse > Slowlimit) { //--
161  default >// if your throttle signal is reverse must change "<" 
162Gain = map(Gaspulse,
163  Slowlimit, Maxspeed, 0, Max_gain );
164NewPos = map(Rxpulse, Antsx, Antdx, (Postsx
165  + Gain), (Postdx - Gain));
166  }
167else {
168NewPos = map(Rxpulse, Antsx, Antdx,
169  Postsx, Postdx);
170  }
171if (abs(NewPos - OldPos)> Tolerance) {
172OldPos = NewPos;
173myservo.write(NewPos
174  + Center);
175
176if (OldPos > Streight+Blinkpoint) digitalWrite(led1, (millis()
177  / 100) % 2); //--default 100 is led blink speed 
178              
179 else   digitalWrite(led1,
180  LOW);  
181if (OldPos < Streight-Blinkpoint) digitalWrite(led2, (millis() / 100)
182  % 2); //--default 100 is led blink speed 
183               
184  else  digitalWrite(led2,
185  LOW);  
186
187}
188}