//https://docs.wokwi.com/parts/wokwi-attiny85   simulate ATTINY85 on wokwi
//https://wokwi.com/projects/317140124437578305  get interrupts working
// https://wokwi.com/projects/318885209198035539  debounce function.
// https://thewanderingengineer.com/2014/08/11/pin-change-interrupts-on-attiny85/ datasheet attiny85 ints.
//https://electronics.stackexchange.com/questions/264434/attiny85-interrupt-confusion "only PB2 on attiny85 can be used to trap edge changes"
#include <TinyDebug.h>
#include <avr/io.h>
#include <avr/interrupt.h>

#define INTERRUPT_PIN PCINT2 
#define clockin PB2    //use digital I/O pin PB1 (pin 6 of IC) for input
#define INT_VECTOR INT0_vect 
#define LED PB0

volatile byte x = 0;

const int debounceDelay = 10; // milliseconds to wait until button input stable *



void setup() {
    
    pinMode(LED, OUTPUT);  //PB0 is GPIO output
    
     

    cli();                            // Disable interrupts during setup
 
    PCMSK = 0b00000100;  //enable PB2/PCINT2 as our interrupt pin.

    GIMSK = 0b01100000;  // enable ext pin interrupts; enable pin changes to be treated as interrupts.
    
    MCUCR = 0b00000011; // int rising edge only. In wiwok unclick "bounce" 

    pinMode(clockin, INPUT_PULLUP);   // Set our interrupt pin as input with a pullup 
    sei();      
    Debug.begin();  
  //Debug.println("you are beginning the sketch");
 
 
}

void loop() {
  Debug.print("value of X is: ");
  Debug.println(x);
  }


ISR(INT_VECTOR) {
    
if (debounce(clockin))
    {
         
   
  
        x++;
       delay(1000);
 
       

    }
}

boolean debounce(int pin)
{
  boolean state;
  boolean previousState;
  previousState = digitalRead(pin); // store switch state
  for (int counter = 0; counter < debounceDelay; counter++)
  {
    delay(100); // wait for 1 millisecond
    Debug.println("you are in debounce function.");
    state = digitalRead(pin); // read the pin
    if ( state != previousState)
    {
      counter = 0; // reset the counter if the state changes
      previousState = state; // and save the current state
    }
  }
  // here when the switch state has been stable longer than the debounce period
  return state;
}