ATtiny 85 not waking up

Projects Programming
4

Thanks for all the replies
But changing it to LOW did not help.

In the data sheet it mentions.

Only an External Reset, a Watchdog Reset, a Brown-out Reset, USI start condition interupt, an external level interrupt on INT0 or a pin change interrupt can wake up the MCU.

Where can I get more information on waking the attiny85 with attachInterupt on LOW.

Also I have changed my sleepnow() and interrupt routine as below but it still does not wake up.

Thanks

void rpm ()     //This is the function that the interupt calls
{
  NbTopsFan++;  //This function measures the rising and falling edge of the hall effect sensors signal
  sleep_disable();
  digitalWrite(helperLED, HIGH);
}


void sleepNow()
{ //sei();
  sleep_cpu();
}