#define ENC1A 2 
#define ENC1B 4 
#define ENC2A 3 
#define ENC2B 5

volatile int pos1i = 0; // specify pos1i as volatile
volatile int pos2i = 0; // specify pos2i as volatile

void readEncoder1(){
  int b = digitalRead(ENC1B);
  if(b > 0){
    pos1i++;
  }
  else{
    pos1i--;
  }}

void readEncoder2(){
  int b = digitalRead(ENC2B);
  if(b > 0){
    pos2i++;
  }
  else{
    pos2i--;
  }
}

void setup() {

    
  Serial.begin(9600);
  pinMode(ENC1A,INPUT);
  pinMode(ENC1B,INPUT);
  pinMode(ENC2A,INPUT);
  pinMode(ENC2B,INPUT);
  attachInterrupt(digitalPinToInterrupt(ENC1A),readEncoder1,RISING);
  attachInterrupt(digitalPinToInterrupt(ENC2A),readEncoder2,RISING);
}

void loop() {
  float WheelCir = 200; // wheel circumfrance in cm pi*d
  float EncCntsRev = 265; // counts per rev of wheel
  int pos1 = 0;
  int pos2 = 0;

  noInterrupts(); // disable interrupts temporarily while reading
  pos1 = pos1i;
  pos2 = pos2i;
  interrupts(); // turn interrupts back on
  
float DistanceA = ( WheelCir/ EncCntsRev) * pos1;  
 float DistanceB = ( WheelCir/ EncCntsRev) * pos2;
  Serial.print("Encoder 1 ");
  Serial.print(DistanceA);
  Serial.print("  Encoder 2 ");
  Serial.print(DistanceB);
  Serial.println(" Distance (cm)"); 

}