#include <avr/io.h>
#include <avr/interrupt.h>

#include "output.h"

void init_pwm()
{
  // Enable output on the LED PA7/PIN6
  DDRA |= (1 << 7);

  // Configure OC0A/PB2/Pin5 as output
  DDRB |= (1 << 2);

  // Enable Fast PWM via Wave Generation Mode bits (P.81)
  TCCR0A |= (1 << WGM01) | (1 << WGM00); 

  // Enable Phase Correct PWM
  //TCCR0A |= (0 << WGM02) | (0 << WGM01) | (1 <<WGM00);

  // Timer/Clock Control Register
  // Enable PWM on both OC0A and OC0B pins
  TCCR0A |= (1 << COM0B1);
  TCCR0A |= (1 << COM0A1);  

  out_duty(127);
}

// ------------------------------------------------------------
// we use a 16 bit counter, so we may write a new sample every
// 256 clock cycles
// 
// init_audio_clock writes to a 16 bit register. 
// Call init_audio_clock before calling sei().
void init_audio_clock()
{
  // start Timer Counter 1
  TCCR1B |= (1 << CS10);

  // Wave Generate Mode (P. 108)
  TCCR1B |= (1 << WGM12);

  OCR1A = 10011;// Compare 

  // Timer Overflow Interrupt Enable 
  //TIMSK1 |= (1 << TOIE1); // ISR(TIM1_OVF_vect){

  // Timer Counter 1 Output Compare A Match Interrupt Enable
  TIMSK1 |= (1 << OCIE1A); // ISR(TIM1_COMPA_vect)
}

void out_off()
{
  TCCR0A &= ~(1 << COM0A1);
}

void out_on()
{
  TCCR0A |=(1 << COM0A1);
}