ATtiny85 Interrupt code


I need ATtiny85 Interrupt code example.
I am trying to implement an Interrupt example using ATtiny85 chip.
Please share an example code.
Configuring Pin7 or PB2 as an Input pin to check for external interrupt on the falling edge (button pressed) and Pin5 or PB0 as Output pin which toggles a LED whenever there is an interrupt on Pin7


Does attachInterrupt not work for you? attachInterrupt() - Arduino Reference

attachInterrupt() worked for Arduino UNO but not for ATTiny85

Could you show the code?

#include "LowPower.h"
int SENSEpin = 2; //pin2 arduino uno
int PUMPpin = 3; //pin3 arduino uno
volatile int SENSEflag;

void setup()
digitalWrite (3, LOW);
attachInterrupt(digitalPinToInterrupt(SENSEpin),turnPUMPon,FALLING); //interrupt on falling edge of pin2

void loop()
if (SENSEflag = 1)
digitalWrite (3,HIGH);
digitalWrite (3,LOW);
SENSEflag = 0;

void turnPUMPon()
SENSEflag = 1;

= assignment
== comparison

don’t use digitalPinToInterrupt then

Ok. could u plz suggest what else I could try

Compiles thus

void setup() 
  pinMode(3, OUTPUT);
  digitalWrite(3, LOW);

Maybe digitalPinToInterrupt hasn't been incorporated into the '85 core.
I don't know what that's supposed to accomplish. (It wasn't around the only time I did with an Interrupt (10 years ago).)

Ok, here is what I have. attachInterrupt is indeed doesn't seem to work, but interrupts on INT0 work. So in this sketch, the internal LED on digispark ATTiny85 I have will light when PB2 is high and turn off when PB2 is low. I used piece of conductor to connect, disconnect ground to PB2

#define LED_PIN 1
#define INTERRUPT_PIN 2 // INT0 -> PB2

volatile byte i = 0;
void setup() 
  GIMSK |= (1 << INT0); // enable external interrupt
  MCUCR |= (1 << ISC00); // CHANGE mode

  pinMode(LED_PIN, OUTPUT);

void loop()
  digitalWrite(LED_PIN, i);

  i = digitalRead(INTERRUPT_PIN);

An edge trigger interrupt will not wake an ATtiny85 from sleep mode. You need a level change interrupt instead.

This is where an ATtiny85 differs from an ATmega328p etc.

See this and many more:

This is the same as ATmega328P.

In the case of external interrupt (a.k.a INT0,1);
The ATmega328P requires a level trigger to get up from a power down.
It doesn't support edge trigger wakeups, same to ATtiny85.

There is no point in quoting the data sheet in this case. If you follow the links which have been quoted you will see that Atmel acknowledged a mismatch between the behavior of the ATmega328p and the data sheet.

But we should consider it not working until it is reflected in the datasheet and becomes an official statement.