Encoder gives values only in one way

Projects Programming
3

PaulS:
In the first code, you only trigger the interrupt handler when the A pin changes.
In the second code, you only trigger the interrupt handlers when the A and B pins fall.

You need to trigger both handlers when the corresponding pin CHANGES.

int pulses;                              //Output pulses.

int encoderA = 3;
int encoderB = 2;
int pulsesChanged = 0;

void setup() {
  Serial.begin(115200);
   pinMode(encoderA, INPUT); //3
  pinMode(encoderB, INPUT); //2
  attachInterrupt(digitalPinToInterrupt(3), A_CHANGE, CHANGE);
  attachInterrupt(digitalPinToInterrupt(2), B_CHANGE, CHANGE);

}//setup

void loop(){

  if (pulsesChanged != 0) {
    pulsesChanged = 0;
    Serial.println(pulses);
  }
}

void A_CHANGE(){
  if( digitalRead(encoderB) == 0 ) {
    if ( digitalRead(encoderA) == 0 ) {
      // A fell, B is low
      pulses--; // moving reverse
    } else {
      // A rose, B is low
      pulses++; // moving forward
    }
  }else {
    if ( digitalRead(encoderA) == 0 ) {
      // B fell, A is high
      pulses++; // moving reverse
    } else {
      // B rose, A is high
      pulses--; // moving forward
    }
  }
  pulsesChanged = 1;
}

void B_CHANGE(){
  if ( digitalRead(encoderA) == 0 ) {
    if ( digitalRead(encoderB) == 0 ) {
      // B fell, A is low
      pulses++; // moving forward
      //Serial.println("a");
    } else {
      // B rose, A is low
      pulses--; // moving reverse
      //Serial.println("b");
    }
 } else {
    if ( digitalRead(encoderB) == 0 ) {
      // B fell, A is high
      pulses--; // moving reverse
    } else {
      // B rose, A is high
      pulses++; // moving forward
    }
  }
  pulsesChanged = 1;
}

In this case the output is like this :

-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0
-1
0