avr.cpp


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#include "avr.h"
#include "adc.h"
#include "global.h"
#include "util.h"

#include <stdint.h>


int getButton() {
  uint16_t val = getADCValue(7);
  
  if(val < 144) return 5;
  if(val < 228) return 4;
  if(val < 304) return 3;
  if(val < 376) return 2;
  if(val < 600) return 1;
  
  return 0;
}

void waitForButton(int i) {
  while(getButton() != CLAMP(0, i, 5));
  while(getButton() != 0);
}

void beep(unsigned long freq) {
	const int prescalers[7] = {1, 8, 32, 64, 128, 256, 1024};
	
	for(int i = 0; i < 7; i++) {
		if(F_CPU/freq/2/prescalers[i] <= 256) {
			TCCR2 = (TCCR2&~0x07)|(i+1);
			OCR2 = F_CPU/freq/2/prescalers[i] - 1;
			
			return;
		}
	}
	
	beepOff();
}

void beepOff() {
	TCCR2 &= ~0x07;
}