attiny85 interrupt rising edge

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1

Hello,
Im programming a ATtiny85 with this library http://hlt.media.mit.edu/?p=1229 .
I want to create an interrupt on pin1 and im using this code:

  sbi(GIMSK,PCIE); // Turn on Pin Change interrupt
  sbi(PCMSK,PCINT1); // Which pins are affected by the interrupt

the interrupt works as expected, it fires an interrupt on state Change.
Now i only want the interrput to fire on rising edge and not on state change.
Can anybody help me?
thanx

2

The ISR could detect the state of the pin and only respond to the rising transition. Or use INT0 on PB2, which can sense a rising or falling edge.

3

Oops i missed that. thank you
My question now is that can i get out of sleep with INT0?
here is my working code with state Change interrupt

#include <avr/sleep.h>

#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#endif
#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#endif

int pinLed = 0;
int trimPin=3;

void setup(){
  pinMode(pinLed,OUTPUT);
  pinMode(1,INPUT);
  pinMode(3,INPUT);
  
  sbi(GIMSK,PCIE); // Turn on Pin Change interrupt
  sbi(PCMSK,PCINT1); // Which pins are affected by the interrupt
}

void loop(){

  digitalWrite(pinLed,HIGH); 
  delay(2000);
  digitalWrite(pinLed,LOW);

  
  system_sleep();
}

void system_sleep() {
  cbi(ADCSRA,ADEN); // Switch Analog to Digital converter OFF
  set_sleep_mode(SLEEP_MODE_PWR_DOWN); // Set sleep mode
  sleep_mode(); // System sleeps here
  sbi(ADCSRA,ADEN);  // Switch Analog to Digital converter ON
}

ISR(PCINT0_vect) {
}
4

Lucky13_:
Oops i missed that. thank you

You bet.

My question now is that can i get out of sleep with INT0?

Absolutely, either INT0 or a pin change will wake the MCU. Here's one example: AVR microcontroller sleep demonstrations · GitHub (ATtiny example is below the ATmega example).

5

thanx again jack.
i used the code you mentioned and its working as expected, but this detects the low level.
MCUCR &= ~(_BV(ISC01) | _BV(ISC00));      //INT0 on low level

according to the datasheet setting ISC01 and ISC00 to "1" it detects the rising edge.
im trying this change

MCUCR |= (_BV(ISC01) | _BV(ISC00));      //INT0 rising edge

but its not working.. any idea why?

6

Oh wait, sorry, my bad. INT0 must be set to a level-based interrupt (ISC01:00 either 00 or 01) to wake the MCU according to the datasheet. Edge detection requires the system clock to be running, which it isn't in sleep mode.