Smart Battery Charger Multiplexer with Smart Display

1#include <Wire.h>
2#include <LiquidCrystal_I2C.h> // Using version 1.2.1
3#include  <timer.h>
4#include <HCSR04.h>
5
6auto timer = timer_create_default(); //  create a timer with default settings
7
8// The LCD constructor - address shown  is 0x27 - may or may not be correct for yours
9// Also based on YWRobot LCM1602  IIC V1
10LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
11
12int  zcnt = 0;
13int acnt = 0; // general purpuse right now
14int chargeTime = (10  * 1000); // how much time to spend on each battery
15int charge_time_counter =  59; // how many chargetimes were passed?
16int charge_time_max = 60; // how many  chargetimes were passed?
17int relay1 = 3; // each relay on it's own pin
18int  relay2 = 4;
19int relay3 = 5;
20int relay4 = 6;
21int current_relay = 0; // which  relay is the one on now?
22int max_relays = 3; // how may relays - 0 based. Start  expecting all three.
23float volts1; // what's the voltage of each battery
24float  volts2;
25float volts3;
26int min_volts = 1; // what is the minimum voltage a  batter voltage should be to be charged.
27int volts_update_count = 5; // how often  to update the voltage reading in seconds
28int volts_update_counter = 0; // track  the count of seconds gone by
29int volts_update = (500);
30int read_distance_update  = (500); // update the distance reader every millis
31int time_on_counter = 0;  // counter for the display on/off
32int time_on_count = 100; //seconds to be on
33int  heart_beat = 0; // flip this 0 to 1 to 0 to show the heart beat
34
35UltraSonicDistanceSensor  distanceSensor(11, 12);  // Initialize sensor that uses digital pins 13 and 12.
36int  distance;
37
38int relays[] = { relay1, relay2, relay3 };
39int is_live[] = {  0, 0, 0}; // 1 if live, 0 if not. I have only 3
40
41int debug = 5; // set this  to the level of debug msgs to go to the serial printer
42
43void all_change_to(int  which) { // change all relays to HIGH or LOW, you tell me which:)
44  digitalWrite(relay1,  which);
45  digitalWrite(relay2, which);
46  digitalWrite(relay3, which);
47}
48
49void  toggle_relays(int whichOne) {
50  lcd.setCursor(0, 0); // show which relay is the  current one on
51  lcd.print("Relay on:");
52  lcd.print(current_relay + 1);  // current_relay is zero based
53  all_change_to(HIGH); // turn all off first
54  digitalWrite(relays[current_relay], LOW); // and set the one that should be on  on
55  acnt++; // just a counter to show me it's working
56  lcd.print("  ");
57  lcd.print(acnt);
58}
59
60void checkRelays() {
61  // move the current_relay  to the next relay
62  // if we hit the max, start at 0
63  // while you're here,  call toggle_relays to make sure we're not charge a blank or dead one
64  charge_time_counter++;
65  if (charge_time_counter >= charge_time_max) {
66    current_relay++;
67    if  (current_relay >= max_relays) {
68      current_relay = 0;
69    }
70    toggle_relays(current_relay);
71    charge_time_counter = 0;
72  }
73}
74
75void read_distance() {
76  // reaad  the distance of anything from the HC-S204
77  // if it's something within 80cm  then turn the display on and reset the display on counter
78  // if the counter  is reached then nothing is within 80cm so turn the display off
79  distance = distanceSensor.measureDistanceCm();
80  // uncomment these to see the actual distance measured
81  // Serial.print("Distance  in CM: ");
82  // Serial.println(distance);
83  if (distance < 80) { // can be  anything under 200 for my system uncomment above and check yours
84    lcd.backlight();   // turn display on
85    time_on_counter = 0;
86  } else { // maybe going off?
87    time_on_counter++;
88    if (time_on_counter > time_on_count) {
89      time_on_counter  = 0;
90      lcd.noBacklight();
91    }
92  }
93}
94
95void read_show_volts()  {
96  // read the volts at each battery input
97  // then if less then min_volts,  there is nothing there worth charging, skip that connection
98  // this gets called  over and over so if a wire gets knocked off or
99  // whatever it won't be in the  charge loop
100  volts1 = analogRead(0);
101  volts1 = (volts1 * 0.016);
102  lcd.setCursor(0,  1); lcd.print("                "); // clear the line
103  lcd.setCursor(11, 0);
104  lcd.print(volts1);
105  volts2 = analogRead(1);
106  volts2 = (volts2 * 0.0164);
107  lcd.setCursor(4, 1);
108  lcd.print(volts2);
109  volts3 = analogRead(2);
110  volts3 = (volts3 * 0.0166);
111  lcd.setCursor(11, 1);
112  lcd.print(volts3);
113  // now test the voltages. If less than 10, then let's assume dead/bad or no battery
114  // so take it out of rotation
115  // start by clearing all relays out
116  int  temp_cnt = 0;
117  // set all arrays to 0 - that's off
118  relays[0] = 0;
119  relays[1]  = 0;
120  relays[2] = 0;
121  if (volts1 > min_volts) {
122    relays[temp_cnt]  = relay1;  // relay 1 is good
123    temp_cnt++;
124  }
125  if (volts2 > min_volts)  {
126    relays[temp_cnt] = relay2;  // relay 2 is good
127    temp_cnt++;
128  }
129  if (volts3 > min_volts) {
130    relays[temp_cnt] = relay3;  // relay 3 is good
131    temp_cnt++;
132  }
133  max_relays = temp_cnt;
134  // this is a heart bet on  the lcd - just shows me it's running
135  lcd.setCursor(0, 1);
136  if (heart_beat  == 1) {
137    lcd.print("<>");
138    heart_beat = 0;
139  } else {
140    lcd.print("><");
141    heart_beat = 1;
142  }
143  lcd.print(charge_time_counter);
144  read_distance();
145}
146
147void  setup()
148{
149  Serial.begin(19200);
150  Serial.println("Starting");
151  lcd.begin(16,  2); // sixteen characters across - 2 lines
152  lcd.backlight();
153  pinMode(relay1,  OUTPUT);
154  pinMode(relay2, OUTPUT);
155  pinMode(relay3, OUTPUT);
156  all_change_to(HIGH);
157  // setup timers. 3 timers - the time to turn the charger on each battery,
158  // how often to show the voltage update
159  // and how often to check for distance  read to turn on the display
160  read_show_volts(); // do the first time so we don't  have to wait for the timer.
161  checkRelays();
162  timer.every(chargeTime, checkRelays);
163  timer.every(volts_update, read_show_volts);
164}
165
166void loop()
167{
168  timer.tick();  // tick the timer
169}
170
171