static void startAudioHiFi()
{
backupPreMozziTimer1();
// pwm on timer 1
pinMode(AUDIO_CHANNEL_1_highByte_PIN, OUTPUT); // set pin to output for audio, use 3.9k resistor
pinMode(AUDIO_CHANNEL_1_lowByte_PIN, OUTPUT); // set pin to output for audio, use 499k resistor
Timer1.initializeCPUCycles(16000000UL/125000, FAST); // set period for 125000 Hz fast pwm carrier frequency = 14 bits
Timer1.pwm(AUDIO_CHANNEL_1_highByte_PIN, 0); // pwm pin, 0% duty cycle, ie. 0 signal
Timer1.pwm(AUDIO_CHANNEL_1_lowByte_PIN, 0); // pwm pin, 0% duty cycle, ie. 0 signal
backupMozziTimer1();
// audio output interrupt on timer 2, sets the pwm levels of timer 1
setupTimer2();
}
// avr architecture
static void startAudioStandard()
{
backupPreMozziTimer1();
pinMode(AUDIO_CHANNEL_1_PIN, OUTPUT); // set pin to output for audio
#if (AUDIO_MODE == STANDARD)
Timer1.initializeCPUCycles(16000000UL/AUDIO_RATE, PHASE_FREQ_CORRECT); // set period, phase and frequency correct
#else // (AUDIO_MODE == STANDARD_PLUS)
Timer1.initializeCPUCycles(16000000UL/PWM_RATE, FAST); // fast mode enables higher PWM rate
#endif
Timer1.pwm(AUDIO_CHANNEL_1_PIN, AUDIO_BIAS); // pwm pin, 50% of Mozzi's duty cycle, ie. 0 signal
TIMSK1 = _BV(TOIE1); // Overflow Interrupt Enable (when not using Timer1.attachInterrupt())
backupMozziTimer1();
}
