PWMChargeController

#include <Wire.h>
#include <LiquidCrystal.h>

#define SOL_ADC A0     // Solar panel side voltage divider is connected to pin A0 
#define BAT_ADC A1    // Battery side voltage divider is connected to pin A1
#define CURRENT_ADC A2  // ACS 712 current sensor is connected to pin A2
#define TEMP_ADC A5   // LM 35 Temperature is connected to pin A3
#define AVG_NUM 150    // number of iterations of the adc routine to average the adc readings
#define BAT_MIN 10.5  // minimum battery voltage for 12V system
#define BAT_MAX 15.0  // maximum battery voltage for 12V system
#define BULK_CH_SP 14.4 // bulk charge set point for sealed lead acid battery // flooded type set it to 14.6V
#define FLOAT_CH_SP 13.6  //float charge set point for lead acid battery
#define LVD 11.5          //Low voltage disconnect setting for a 12V system
#define PWM_PIN 3         // pin-3 is used to control the charging MOSFET //the default frequency is 490.20Hz
#define LOAD_PIN 2       // pin-2 is used to control the load
//#define BAT_RED_LED 5
//#define BAT_GREEN_LED 6
//#define BAT_BLUE_LED 7
//#define LOAD_RED_LED 8
//#define LOAD_GREEN_LED 9

LiquidCrystal lcd(12, 11, 10, 4, 5, 6, 7);

byte solar[8] = //icon for solar panel
{
    0b11111,0b10101,0b11111,0b10101,0b11111,0b10101,0b11111,0b00000
};
byte battery[8] =  //icon for battery
{
  0b01110,0b11011,0b10001,0b10001,0b10001,0b10001,0b10001,0b11111
};

byte energy[8] =  // icon for power
{
    0b00010,0b00100,0b01000,0b11111,0b00010,0b00100,0b01000,0b00000
};
/*byte alarm[8] =  // icon for alarm
{
 0b00000,0b00100,0b01110,0b01110,0b01110,0b11111,0b00000,0b00100
};*/
byte temp[8] = //icon for termometer
{
  0b00100,0b01010,0b01010,0b01110,0b01110,0b11111,0b11111,0b01110
};

byte charge[8] = // icon for battery charge
{
    0b01010,0b11111,0b10001,0b10001,0b10001,0b01110,0b00100,0b00100,
};
byte not_charge[8]=
{
    0b00000,0b10001,0b01010,0b00100,0b01010,0b10001,0b00000,0b00000,
};


float solar_volt=0;
float bat_volt=0;
float load_current=0;

int temperature=0;
int temp_change=0;
int Vo;
float R1 = 7100;
float logR2, R2, T, Tc, Tf;
float c1 = 1.009249522e-03, c2 = 2.378405444e-04, c3 = 2.019202697e-07;

float system_volt=0;
float bulk_charge_sp=0;
float float_charge_sp=0;
float charge_status=0;
float load_status=0;
float error=0;
float Ep=0;
int duty =0;
float lvd;
float msec=0;
float last_msec=0;
float elasped_msec=0;
float elasped_time=0;
float ampSecs = 0;
float ampHours=0;
float watts=0;
float wattSecs = 0;
float wattHours=0;
int backLight = 13;  // pin 13 will control the backlight
int charged_percent = 0; 

void setup()
{
  Serial.begin(9600);
//  pinMode(BAT_RED_LED,OUTPUT);
//  pinMode(BAT_GREEN_LED,OUTPUT);
//  pinMode(BAT_BLUE_LED,OUTPUT);
//  pinMode(LOAD_RED_LED ,OUTPUT);
//  pinMode(LOAD_GREEN_LED,OUTPUT);

  pinMode(PWM_PIN,OUTPUT);
  pinMode(LOAD_PIN,OUTPUT);
  digitalWrite(PWM_PIN,LOW);  // default value of pwm duty cycle
  digitalWrite(LOAD_PIN,LOW);  // default load state is OFF
  pinMode(backLight, OUTPUT);          //set pin 13 as output
  analogWrite(backLight, 150);        //controls the backlight intensity 0-255
  lcd.begin(16,2);                     // columns, rows. size of display
  lcd.clear();                         // clear the screen
}

void loop(){
  lcd.setCursor(16,1); // set the cursor outside the display count
  lcd.print(" ");      // print empty character

  Vo = analogRead(TEMP_ADC);
  R2 = R1 * (1023.0 / (float)Vo - 1.0);
  logR2 = log(R2);
  T = (1.0 / (c1 + c2*logR2 + c3*logR2*logR2*logR2));
  Tc = T - 277.15;
  Tf = (Tc * 9.0)/ 5.0 + 32.0; 
  
  read_data();             // read different sensors data from analog pin of arduino
  system_voltage();        // detect the system voltage according to battery voltage
  setpoint();      // decide the charge set point according to system voltage
  charge_cycle();         // pwm charging of battery
  power();                // calculate the load power and energy
  load_control();         //control the load
  //led_indication();       // led indica
  print_data();            // print in serial monitor
  lcd_display();           // lcd display

  charged_percent = bat_volt*10;   
  charged_percent = map(bat_volt*10, 30 , 62, 0, 100);
}

int read_adc(int adc_parameter){
  int sum = 0;
  int sample ;
  for (int i=0; i<AVG_NUM; i++) 
  {                                        // loop through reading raw adc values AVG_NUM number of times  
    sample = analogRead(adc_parameter);    // read the input pin  
    sum += sample;                        // store sum for averaging
    delay(2);                           // pauses for 
  }
  return(sum / AVG_NUM);                // divide sum by AVG_NUM to get average and return it
}

void read_data(void) {
  // 5V = ADC value 1024 => 1 ADC value = (5/1024)Volt= 0.0048828Volt
  // Vout=Vin*R2/(R1+R2) => Vin = Vout*(R1+R2)/R2   R1=100 and R2=20
  solar_volt = read_adc(SOL_ADC)*0.0048828*(120/20);
  bat_volt   = read_adc(BAT_ADC)*0.0048828*(120/20);       
  load_current = (read_adc(CURRENT_ADC)*0.0048828 -25); 
  temperature = Tc;
}
  
void power(void){
  msec = millis();
  elasped_msec = msec - last_msec; //Calculate how long has past since last call of this function
  elasped_time = elasped_msec / 1000.0; // 1sec=1000 msec
  watts = load_current * bat_volt; //Watts now
  ampSecs = (load_current*elasped_time); //AmpSecs since last measurement
  wattSecs = ampSecs * bat_volt; //WattSecs since last measurement
  ampHours = ampHours + ampSecs/3600; // 1 hour=3600sec //Total ampHours since program started
  wattHours = wattHours + wattSecs/3600; // 1 hour=3600sec //Total wattHours since program started
  last_msec = msec; //Store 'now' for next time
}

void print_data(void) {
  delay(100);
  Serial.print("Solar Panel Voltage: ");
  Serial.print(solar_volt);
  Serial.println("V");
  Serial.print("Battery Voltage: ");
  Serial.print(bat_volt);
  Serial.println("V");
  Serial.print("Syestem Voltage: ");
  Serial.print(system_volt);
  Serial.println("V");
  Serial.print("Charge Set Point:");
  Serial.println(bulk_charge_sp);
  Serial.print("Temperature:");
  Serial.print(temperature);
  Serial.println("C");
  Serial.print("Load Current: ");
  Serial.print(load_current);
  Serial.println("A");
  Serial.print("Power: ");
  Serial.print(watts);
  Serial.println("W");
  Serial.print("Energy: ");
  Serial.print(wattHours);
  Serial.println("WH");
  Serial.print("Duty Cycle :");

  if (charge_status==1)
  {
    Serial.println("99%");
    Serial.println("BULK CHARGING");
  }else if (charge_status==2)
  {
    Serial.print(Ep);
    Serial.println("%");
    Serial.println("FLOAT CHARGING");
  }else{
    Serial.println("0%");
    Serial.println("NOT CHARGING");
  }
  if(load_status==1){
    Serial.println("LOAD IS CONNECTED"); 
  }else{
    Serial.println("LOAD IS DISCONNECTED");   
  }
  Serial.println("***************************");
}

void system_voltage(void){
    if ((bat_volt >BAT_MIN) && (bat_volt < BAT_MAX)){
        system_volt = 12;
    }
    else if ((bat_volt > BAT_MIN/2 ) && (bat_volt < BAT_MAX/2)){
        system_volt = 6;
    }
}
 
void setpoint(void){
  temp_change = temperature-22.0; // 22deg cel is taken as standard room temperature 
  // temperature compensation = -5mv/degC/Cell 
  // If temperature is above the room temp ;Charge set point should reduced
  // If temperature is bellow the room temp ;Charge set point should increased
  if(system_volt ==12)
  {
    bulk_charge_sp = BULK_CH_SP-(0.030*temp_change) ;
    float_charge_sp=FLOAT_CH_SP-(0.030*temp_change) ;
    lvd =LVD;
  }
  
  else if(system_volt ==6)
  {
    bulk_charge_sp = (BULK_CH_SP/2)-(0.015*temp_change) ;
    float_charge_sp= (FLOAT_CH_SP/2)-(0.015*temp_change) ;
    lvd=LVD/2;
  }
  
}

void charge_cycle(void){
  if (solar_volt > bat_volt && bat_volt <= bulk_charge_sp)
  {
    if (bat_volt <= float_charge_sp) // charging start
    {  
      charge_status = 1; // indicate the charger is in BULK mode
      duty= 252.45;
      analogWrite(PWM_PIN,duty); // 99 % duty cycle // rapid charging 
    }
    else if (bat_volt > float_charge_sp && bat_volt <= bulk_charge_sp){   
      charge_status = 2; // indicate the charger is in FLOAT mode
      error  = (bulk_charge_sp - bat_volt);      // duty cycle reduced when the battery voltage approaches the charge set point
      Ep = error *100 ; //Ep= error* Kp // Assume  Kp=100
      
      if(Ep < 0) 
      { 
        Ep=0;
      }else if(Ep>100){
        Ep=100;
      }else if(Ep>0 && Ep <=100){
        duty = (Ep*255)/100;
      }
      analogWrite(PWM_PIN,duty);
    }
  }else{
    charge_status=0;  // indicate the charger is OFF
    duty=0;
    analogWrite(PWM_PIN,duty);
  }
}

void load_control(){
  if (solar_volt < 5  ) // load will on when night
  { 
    if(bat_volt >lvd){
      load_status=1;
      digitalWrite(LOAD_PIN, HIGH); // load is ON
    }else if(bat_volt < lvd){
      load_status=0;
      digitalWrite(LOAD_PIN, LOW); //load is OFF
    }
  }else{
    load_status=0;
    digitalWrite(LOAD_PIN, LOW);
  }
}

//void led_indication(void){
//  battery_led();           //Battery status led indication
//  load_led();              //Load led indication
//}

//void battery_led(void){  
//  if( (bat_volt > system_volt) && ( bat_volt <bulk_charge_sp)){   
//    leds_off_all();
//    digitalWrite(BAT_GREEN_LED,LOW);  // battery voltage is healthy
//  } 
//  else if(bat_volt >= bulk_charge_sp) {
//    leds_off_all();
//    digitalWrite(BAT_BLUE_LED,LOW);  //battery is fully charged
//  }
//  else if(bat_volt < system_volt){
//    leds_off_all();
//    digitalWrite(BAT_RED_LED,LOW);  // battery voltage low
//  }
//}

//void load_led(){
//    if(load_status==1){
//        digitalWrite(LOAD_GREEN_LED,HIGH);
//    }
//    else if(load_status==0){
//        digitalWrite(LOAD_RED_LED,HIGH);
//    }
//}

//void leds_off_all(void)
//{
//  digitalWrite(BAT_RED_LED,HIGH);
//  digitalWrite(BAT_GREEN_LED,HIGH);
//  digitalWrite(BAT_BLUE_LED,HIGH);
//  digitalWrite(LOAD_RED_LED, LOW);
//  digitalWrite(LOAD_GREEN_LED, LOW);
//}

void lcd_display(){
  lcd.setCursor(0,0); // set the cursor at 1st col and 1st row
  lcd.print("SOL:");
  lcd.print(solar_volt);
  lcd.print(" BAT:");
  lcd.print(bat_volt);
  lcd.setCursor(1,1); // set the cursor at 1st col and 2nd row

  delay(500);
  
  if (charge_status == 0)
 {
  lcd.print("Fully Charged ");
 }
  // LCD will show the %charged during charging period only
  if (charge_status == 1)
 {
  lcd.print(charged_percent);
  lcd.print("% Charged BM");
 }
  if (charge_status == 2)
 {
  lcd.print(charged_percent);
  lcd.print("% Charged FM");
 }
 // LCD will alart when battery is dead by displaying the message "BATTERY IS DEAD!!"
 else if (bat_volt < 3)
 {
  lcd.print("BATTERY IS DEAD!!");
 }

 if (bat_volt < 3.2 && bat_volt > 3)
// seecond restriction is given for indicating battery is dead
// if you omit the (bat_volt > 6) when ever battery is dead also display bat discharged
{
  lcd.setCursor(1,1);
  lcd.print("BAT DISCHARGED..");
 }
  
  /*
  lcd.setCursor(0, 0);
  lcd.write(1);
  lcd.setCursor(2, 0);
  lcd.print(solar_volt);
  lcd.print("V");
  lcd.setCursor(14, 0);
  lcd.write(5);
  lcd.setCursor(16, 0);
  lcd.print(temperature);
  lcd.write(0b11011111);
  lcd.print("C");
  lcd.setCursor(0,1);
  lcd.write(2);
  lcd.setCursor(2, 1);
  lcd.print(bat_volt);
  lcd.print("V");
  lcd.setCursor(14, 1);
  lcd.write(2);
  if((charge_status==1) | (charge_status== 2)){
    lcd.write(6);
  }
  else{
    lcd.write(7);
  }
  lcd.setCursor(0,2);
  lcd.write(3);
  lcd.setCursor(2,2);
  lcd.print(load_current); 
  lcd.print("A");
  lcd.setCursor(13,2); 
  lcd.print(watts); 
  lcd.print("W"); 
  lcd.setCursor(0,3);
  lcd.print("Energy:"); 
  lcd.print(wattHours);
  lcd.print("WH"); 
  */
}