const int EncoderPin1 = 7 ; //set the encoder pin A
const int EncoderPin2 = 6; //set the encoder pin B
int encoderPin2Value = 0 ; //store the encoder value 
 
volatile int motorPosition = 0 ; // the initial position of the motor 
float previousmotorPosition = -1 ; // the previous motor position 

int MotorDirection ; // store the direction 
int RotaryCLK = 5 ;  // the CLK pin of the rotary encoder or OUTPUT A 
int RotaryDT = 4 ; // the DT pin or the OUTPUT B
int RotarySW = 3 ;  // the button pin of the rotary encoder 
int SW_buttonValue = 0; // storing the button value 

int RotaryValue ; // value manupilated by the encoder 
int RotaryTime ; // store the time of that need the encoder

volatile int encoderPosition = 0 ; // the initial encoder position 
float   encoderPreviousPosition = -1 ; // store the last position of the encoder 

int RightDirectionPin = 12 ; //define the in1
int LeftDirectionPin = 11 ; //define the in2 


int CLKNow ;  // the information came from the rotary_clk  
int CLKPrevious ; 
int DTNow ; // the information came from the rotary_DT 
int DTPrevious ;

int TargetPosition ; // the position of the target to reach 

float currentTime  = millis(); // the current time on millis()
float previousTime ;
float errorValue ; // store the error value 
float previousError ; 
float error ; // the error or  motorPosition - targetPosition

float controlSignal = 0; // Also called as process variable (PV)

//PID parameters - tuned by the user
double kp = 1.35 ;
double ki = 0.00005;
double kd = 0.01;

void setup() {

Serial.begin(115200);

pinMode(EncoderPin1,INPUT);
pinMode(EncoderPin2,INPUT);
attachInterrupt(digitalPinToInterrupt(EncoderPin1),CheckEncoder,RISING);

pinMode(RightDirectionPin,OUTPUT);
pinMode(LeftDirectionPin,OUTPUT);

pinMode( RotaryCLK,INPUT_PULLUP);
pinMode( RotaryDT,INPUT_PULLUP);
pinMode( RotarySW,INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(EncoderPin2),RotaryEncoder,CHANGE);

// store states 
CLKPrevious = digitalRead(RotaryCLK);
DTPrevious = digitalRead(RotaryDT);

}

void loop() {

calculatePID();

DriveMotor();

CheckRotaryButton();

}
void CheckEncoder(){

encoderPin2Value = digitalRead(EncoderPin2);

if(encoderPin2Value == 1) //cw
{
  motorPosition++ ;
}
else if(encoderPin2Value == 0) //ccw
{
  motorPosition-- ;
}
}
void DriveMotor(){

if(controlSignal < 0){

 MotorDirection = -1 ; // go left

}
else if(controlSignal >0)
{
  MotorDirection = 1 ; // go right
}
else
{
 MotorDirection = 0 ; // stop

}
 if(MotorDirection == -1)
 {
  digitalWrite(RightDirectionPin,LOW);
  digitalWrite(LeftDirectionPin,HIGH);
 }
 else if(MotorDirection == 1){
  digitalWrite(RightDirectionPin,HIGH);
  digitalWrite(LeftDirectionPin,LOW);
 }
 else{
  digitalWrite(RightDirectionPin,LOW);
  digitalWrite(LeftDirectionPin,LOW);
 }
}

void calculatePID() // the PID calculation or proportional-integral-direvative
{


int DeltaTime = (currentTime - previousTime )/ 1000000 ; // change the result of dt to seconds 

currentTime = previousTime ; 

errorValue = motorPosition - TargetPosition ; // calculate the error value 

double proportionnel = error ;
double integrale =+ error * ki;
double direvative = (error-previousError ); 
previousError = error ; // save the error 

errorValue = (proportionnel*kp)+(integrale*ki)+(direvative*kd); // here the pid is calculated 




}
void RotaryEncoder(){

CLKNow = digitalRead(RotaryCLK);

if(CLKNow != CLKPrevious && CLKNow == 1)
{
  if(RotaryDT != CLKNow) // ccw
  { 
    RotaryValue = RotaryValue - 515 ; // go left or ccw
  }
  else  //cw
  {
     RotaryValue = RotaryValue + 515 ; // the disk on the motor turn right 515 tour to reach a turn of the axe  
  }
 
}
 CLKNow = CLKPrevious ; 
}
void CheckRotaryButton() {

SW_buttonValue = digitalRead(RotarySW);

if(SW_buttonValue == 0) // it depend on the wiring of the rotary encoder 
{
  
  if(millis() - RotaryTime > 1000){
   
    TargetPosition =  RotaryValue ;  

   RotaryTime = millis();  // save time 

  }
}
  
}
                                    // created by BL.MK