#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>
void TimerInit();
unsigned char periode;
ISR (TIMER0_COMPA_vect)
{
  PORTB ^= (1 << PB7);
}
/*
prescaller 8 , Xtal 16MHz
tick = 8/16Mhz= 0.5 us
delay=counter*tick
delay=counter*0.5us
untuk sampling rate 16 khz maka Tsampling= 1/16Khz= 62,5us
counter = 62,5/0.5us = 125

*/
int main(void) {
  DDRB |= _BV(PB7);
  TimerInit(); /// schedule 10ms
  sei();
  /// enable global interupsi
  while (1) {
    sleep_mode(); // sleep
  }
}
void TimerInit(void) {
  // TCNT0 = -250; // reset counter
  TCCR0B = (1 << CS01) ; //prescaller 8
  TIMSK0 |= (1 << OCIE0A); // enable compare maatch interrupt
  TCCR0A |=_BV(WGM01); //mode Timer CTC
  OCR0A = 125;
}