ATtiny85 Hardware PWM, pins 0, 1 & 4

ATtiny85_PWM

// ATtiny85
// Hardware PWM, pins 0, 1 & 4

int main()
{
  sei();

  DDRB = _BV(PORTB0);         // OC0A
  DDRB |= _BV(PORTB1);        // OC0B
  DDRB |= _BV(PORTB4);        // OC1B

  // Timer 0 is fixed frequency? (appears to be 30.6kHz)
  // Timer 0, Channel A
  TCCR0A = _BV(COM0A1) | _BV(WGM01) | _BV(WGM00);
  TCCR0B = _BV(CS00);
  OCR0A = 256 * 0.75 - 1;     // Duty Cycle

  // Timer 0, Channel B
  TCCR0A |= _BV(COM0B1);
  OCR0B = 256 * 0.25 - 1;     // Duty Cycle

  // Timer 1
  TCCR1 = _BV(CS10);
  GTCCR = _BV(COM1B1) | _BV(PWM1B);
  const uint8_t f = 38000;
  OCR1C = 8000000.0 / f - 1;  // Frequency
  OCR1B = f * 0.33;           // Duty Cycle

  for (;;)
  {
  }

  return 0;
}