#include <Arduino.h>

//*************************************************************************
//Pins for rotary encoder and variables
//*************************************************************************
#define CLK_PIN 32 // ESP32 pin GPIO25 connected to the rotary encoder's CLK pin
#define DT_PIN  33 // ESP32 pin GPIO26 connected to the rotary encoder's DT pin
#define SW_PIN  34 // ESP32 pin GPIO27 connected to the rotary encoder's SW pin
#define DIRECTION_CW 0   // clockwise direction
#define DIRECTION_CCW 1  // counter-clockwise direction

volatile int counter = 0;
volatile int direction = DIRECTION_CW;
volatile unsigned long last_time;  // for debouncing
int prev_counter;

//*************************************************************************
//ISR for handling button press
//*************************************************************************
void IRAM_ATTR ISR_button() {
  Serial.println("Button Pressed");
}

//*************************************************************************
//ISR for handling rotary encoder
//*************************************************************************
void IRAM_ATTR ISR_encoder() {
  if ((millis() - last_time) < 50)  // debounce time is 50ms
    return;

  if (digitalRead(DT_PIN) == HIGH) {
    // the encoder is rotating in counter-clockwise direction => decrease the counter
    counter--;
    direction = DIRECTION_CCW;
    Serial.println("Counter-Clockwise");
  } else {
    // the encoder is rotating in clockwise direction => increase the counter
    counter++;
    direction = DIRECTION_CW;
    Serial.println("Clockwise");
  }
  last_time = millis();
}

void setup() {
  Serial.begin(9600);

  pinMode(CLK_PIN, INPUT);
  pinMode(DT_PIN, INPUT);
  pinMode(SW_PIN, INPUT_PULLUP);

  attachInterrupt(digitalPinToInterrupt(CLK_PIN), ISR_encoder, RISING);
  attachInterrupt(digitalPinToInterrupt(SW_PIN), ISR_button, FALLING);
}

void loop() {
  // Main code here
}