#define in1 10
#define in2 11

int s, erro, A,B;
int i=0;
float kp;

void setup() {
  // put your setup code here, to run once:
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(2, INPUT);
  pinMode(3, INPUT);
  Serial.begin(9600);
  A = digitalRead(2);
  B = digitalRead(3);
  attachInterrupt(digitalPinToInterrupt(2), vp, CHANGE);
  attachInterrupt(digitalPinToInterrupt(3), vp, CHANGE);

}

void loop() {
  // put your main code here, to run repeatedly:


 frente(180);
 delay(5000);
 re(180);
 delay(5000);




}

void frente(int pot){
  analogWrite(in1, pot);
  analogWrite(in2, 0);

}



void re(int pot){
  analogWrite(in1, 0);
  analogWrite(in2, pot);

}

void vp(){
  if(A==B){
    if(A!=digitalRead(2)){
      i++;
      A = digitalRead(2);
    }
    if(B!=digitalRead(3)){
      i--;
      B = digitalRead(3);
    }
  }

  else{
    if(A!=digitalRead(2)){
      i--;
      A = digitalRead(2);
    }
    if(B!=digitalRead(3)){
      i++;
      B = digitalRead(3);
    }
  }

Serial.println(i);
}