//Servo motor library
#include <Servo.h>
//Initialize variables
int mode = 0;
int axe = 0;            
int buttonState1 = 0;    
int buttonState2 = 0;   
int prevButtonState1 = 0;
int prevButtonState2 = 0; 
 
int ldrtopr= 0;                // top-right LDR                          
int ldrtopl = 1;               // top-left LDR                          
int ldrbotr = 2;               // bottom-right LDR                     
int ldrbotl = 3;               // bottom-left LDR                   
int topl = 0;
int topr = 0; 
int botl = 0;
int botr = 0;

//Declare two servos
Servo servo_updown;
Servo servo_rightleft;

int threshold_value=10;           //measurement sensitivity

void setup()
{
  Serial.begin(9600);                                //serial connection setup  //opens serial port, sets data rate to 9600 bps
  Serial.println("CLEARDATA");                       //clear all data that’s been place in already
  Serial.println("LABEL,t,voltage,current,power,Mode");   //define the column headings (PLX-DAQ command)

  pinMode(12, INPUT);              //Mode switch Button
  pinMode(11, INPUT);              //Axis switch
  pinMode(A4, INPUT);              //Potentiometer for right-left movement and for up-down movement
  
  servo_updown.attach(5);             //Servo motor up-down movement
  servo_rightleft.attach(6);          //Servo motor right-left movement
}

void loop()
{
//  pv_power();
char Mode;
    float volt = analogRead(A5)*5.0/1023;
    float voltage = 2*volt;                //  Volt=(R1/R1+R2)*Voltage / R1=R2=10Ohms  => voltage=2*volt)
    float current = voltage/20;            //  I=voltage/(R1+R2) 
    float power = voltage*current;
    Serial.print("DATA,TIME,"); // PLX-DAQ command
    Serial.print(voltage);    //send the voltage to serial port
    Serial.print(",");
    Serial.print(current);    //send the current to serial port
    Serial.print(",");
    Serial.print(power);  //send the power to serial port
    Serial.print(",");
    
//    Serial.println(Mode);      
  buttonState1 = digitalRead(12);
  if (buttonState1 != prevButtonState1) {
    if (buttonState1 == HIGH) {
      //Change mode and ligh up the correct indicator  
      if (mode == 1) {
        mode = 0;
      } else {
        mode = 1;
      }
    }
  }
  prevButtonState1 = buttonState1;
  delay(50); // Wait for 50 millisecond(s)
  
  if (mode == 0) {
    Mode='M';
    Serial.println(Mode);   //send Mode "Manual" to serial port    
    manualsolartracker();
  } else { // mode automatic
    Mode = 'A';
    Serial.println(Mode);      
    automaticsolartracker(); //send Mode "Automatic" to serial port
    } 
}

void automaticsolartracker(){
  
     //capturing analog values of each LDR
     topr= analogRead(ldrtopr);         //capturing analog value of top right LDR
     topl= analogRead(ldrtopl);         //capturing analog value of top left LDR
     botr= analogRead(ldrbotr);         //capturing analog value of bot right LDR
     botl= analogRead(ldrbotl);         //capturing analog value of bot left LDR

    // calculating average
     int avgtop = (topr + topl) / 2;     //average of top LDRs
     int avgbot = (botr + botl) / 2;     //average of bottom LDRs
     int avgleft = (topl + botl) / 2;    //average of left LDRs
     int avgright = (topr + botr) / 2;   //average of right LDRs
   
    //Get the different 
     int diffelev = avgtop - avgbot;      //Get the different average betwen LDRs top and LDRs bot
     int diffazi = avgright - avgleft;    //Get the different average betwen LDRs right and LDRs left
    
    //left-right movement of solar tracker
     
      if (abs(diffazi) >= threshold_value){        //Change position only if light difference is bigger then the threshold_value
       if (diffazi > 0) {
        if (servo_rightleft.read() < 180) {
          servo_rightleft.write((servo_updown.read() + 2));
        }
      }
      if (diffazi <  0) {
        if (servo_rightleft.read() > 0) {
          servo_rightleft.write((servo_updown.read() - 2));
        }
      }
    }
             
      //up-down movement of solar tracker

      if (abs(diffelev) >= threshold_value){    //Change position only if light difference is bigger then thethreshold_value
       if (diffelev > 0) {
        if (servo_updown.read() < 180) {
          servo_updown.write((servo_rightleft.read() - 2));
        }
      }
      if (diffelev <  0) {
        if (servo_updown.read() > 0) {
          servo_updown.write((servo_rightleft.read() + 2));
        }
      }
    }       
 }  

void manualsolartracker(){
  buttonState2 = digitalRead(13);
  if (buttonState2 != prevButtonState2) {
    if (buttonState2 == HIGH) {
      //Change mode and ligh up the correct indicator  
      if (axe == 1) {
        axe = 0;
      } else {
        axe = 1;
      }
    }
  }
  prevButtonState2 = buttonState2;
  delay(50); // Wait for 50 millisecond(s)
  if (axe == 0) {     //control right-left movement
    servo_rightleft.write(map(analogRead(A4), 0, 1023, 0, 180));
  } else { // //control up-down movement
    servo_updown.write(map(analogRead(A4), 0, 1023, 0, 180));
  } 
}