Encoder gives values only in one way

Projects Programming
1

Hi,

I want to measure the distance that have been travelled. For this purpose I bought a motor with encoder. Its model is Mitsumi M25N

I did all the connections correct. Encoder works and its lights are on. I put 1k resistor on both digital outputs of encoder to 5V. When I rotated the motor by my hand, values are only goes to one way although I rotated both ways. I tried several codes I attached both of them can anyone tell me what is wrong?

int pulses;                              //Output pulses.
int deg = 0;
int encoderA = 3;
int encoderB = 2;                      //Direction of the motor.
int pulsesChanged = 0;
                  //Change speed of the motor.
void setup(){
  Serial.begin(115200);

  pinMode(encoderA, INPUT); //3
  pinMode(encoderB, INPUT); //2
  attachInterrupt(digitalPinToInterrupt(2), A_CHANGE, CHANGE);


}//setup

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

void A_CHANGE(){                                  //Function that to read the pulses in x1.
  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
    }
  }

  pulsesChanged = 1;
}

In this code I changed the way how interrupt triggered

int pulses;                              //Output pulses.
int deg = 0;
int encoderA = 3;
int encoderB = 2;
const int pwm = 5;                      //Power of motor.
const int dir = 4;                       //Direction of the motor.
int pulsesChanged = 0;
#define total 980                        //x4 pulses per rotation.
#define motorSpeed 180                   //Change speed of the motor.

void setup() {
  Serial.begin(115200);
  attachInterrupt(digitalPinToInterrupt(2), A_CHANGE, FALLING);
  attachInterrupt(digitalPinToInterrupt(3), B_CHANGE, FALLING);

}//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
    } else {
      // B rose, A is low
      pulses--; // moving reverse
    }
 } else {
    if ( digitalRead(encoderB) == 0 ) {
      // B fell, A is high
      pulses--; // moving reverse
    } else {
      // B rose, A is high
      pulses++; // moving forward
    }
  }
  pulsesChanged = 1;
}
2

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.

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
4

Did you look at the examples in the rotary encoder library? Why re-invent the wheel?