Pololu Optical Encoder for Micro Metal Motor

/*
Here's an example code for reading the encoder counts from a Pololu Optical Encoder for Micro Metal Motor using an Arduino:

Note that you may need to modify the pin numbers and interrupt settings depending on your specific setup. Additionally, be sure to connect the encoder channels A and B to the corresponding pins on the Arduino and connect the encoder power supply to the Vin and GND pins on the Pololu board.
*/


const int ENCODER_PIN_A = 2; // encoder channel A pin
const int ENCODER_PIN_B = 3; // encoder channel B pin

volatile long encoderCount = 0; // current encoder count
volatile int lastEncoderA = LOW; // last state of encoder channel A

void setup() {
  // Set up the encoder pins
  pinMode(ENCODER_PIN_A, INPUT_PULLUP);
  pinMode(ENCODER_PIN_B, INPUT_PULLUP);

  // Attach interrupt service routine to encoder channel A
  attachInterrupt(digitalPinToInterrupt(ENCODER_PIN_A), updateEncoderCount, CHANGE);
}

void loop() {
  // Example usage: print the current encoder count
  Serial.println(encoderCount);
}

void updateEncoderCount() {
  // Read the current state of encoder channel A and B
  int encoderA = digitalRead(ENCODER_PIN_A);
  int encoderB = digitalRead(ENCODER_PIN_B);

  // Update the encoder count based on the change in encoder channel A and B
  if (encoderA != lastEncoderA) {
    if (encoderB != encoderA) {
      encoderCount++;
    } else {
      encoderCount--;
    }
  }

  // Save the current state of encoder channel A for the next iteration
  lastEncoderA = encoderA;
}