pwm.c

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/*--------------------------------------------------------------------------*
* PWM output helpers
*---------------------------------------------------------------------------*
* 14-May-2014 ShaneG
*
* These functions provide simulated analog output using PWM channels on
* TIMER0
*--------------------------------------------------------------------------*/
#include <avr/io.h>
#include "iohelp.h"

void pwmInit() {
  TCCR0A = (3<<WGM00); // Enable fast PWM mode
  TCCR0B = (1<<CS00);  // No prescaler
  }

void pwmOut(PWM pwm, uint8_t value) {
  // Make sure the pin is an output
  DDRB |= (1 << pwm);
  if(pwm==PWM0) {
    TCCR0A |= (2<<COM0A0);
    OCR0A = value;
    }
  else if(pwm==PWM1) {
    TCCR0A |= (2<<COM0B0);
    OCR0B = value;
    }
  }