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| author | Dean Camera <dean@fourwalledcubicle.com> | 2010-10-26 06:52:09 +0000 |
|---|---|---|
| committer | Dean Camera <dean@fourwalledcubicle.com> | 2010-10-26 06:52:09 +0000 |
| commit | 08de757811bb2a17d21a35ca08205b4ed64613ff (patch) | |
| tree | e5b2257e3adbe5d0c9d9b1740bf718258584f5c5 /Demos/Device/ClassDriver/AudioInput/AudioInput.c | |
| parent | 55538dcef34bc3c0f2ada4767c51d11202ac0678 (diff) | |
| download | lufa-08de757811bb2a17d21a35ca08205b4ed64613ff.tar.gz lufa-08de757811bb2a17d21a35ca08205b4ed64613ff.tar.bz2 lufa-08de757811bb2a17d21a35ca08205b4ed64613ff.zip | |
Changed AudioInput and AudioOutput demos to reload the next sample via an interrupt rather than polling the sample timer.
Diffstat (limited to 'Demos/Device/ClassDriver/AudioInput/AudioInput.c')
| -rw-r--r-- | Demos/Device/ClassDriver/AudioInput/AudioInput.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/Demos/Device/ClassDriver/AudioInput/AudioInput.c b/Demos/Device/ClassDriver/AudioInput/AudioInput.c index 54e70f6b1..ec81050e3 100644 --- a/Demos/Device/ClassDriver/AudioInput/AudioInput.c +++ b/Demos/Device/ClassDriver/AudioInput/AudioInput.c @@ -63,8 +63,6 @@ int main(void) for (;;) { - ProcessNextSample(); - Audio_Device_USBTask(&Microphone_Audio_Interface); USB_USBTask(); } @@ -91,17 +89,14 @@ void SetupHardware(void) ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | MIC_IN_ADC_MUX_MASK); } -/** Processes the next audio sample by reading the last ADC conversion and writing it to the audio - * interface, each time the sample reload timer period elapses to give a constant sample rate. - */ -void ProcessNextSample(void) +/** ISR to handle the reloading of the data endpoint with the next sample. */ +ISR(TIMER0_COMPA_vect, ISR_BLOCK) { + uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint(); + /* Check if the sample reload timer period has elapsed, and that the USB bus is ready for a new sample */ - if ((TIFR0 & (1 << OCF0A)) && Audio_Device_IsReadyForNextSample(&Microphone_Audio_Interface)) + if (Audio_Device_IsReadyForNextSample(&Microphone_Audio_Interface)) { - /* Clear the sample reload timer compare flag, ready for the next interval */ - TIFR0 |= (1 << OCF0A); - int16_t AudioSample; #if defined(USE_TEST_TONE) @@ -126,6 +121,8 @@ void ProcessNextSample(void) Audio_Device_WriteSample16(&Microphone_Audio_Interface, AudioSample); } + + Endpoint_SelectEndpoint(PrevEndpoint); } /** Event handler for the library USB Connection event. */ @@ -134,6 +131,7 @@ void EVENT_USB_Device_Connect(void) LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING); /* Sample reload timer initialization */ + TIMSK0 = (1 << OCIE0A); OCR0A = (F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1; TCCR0A = (1 << WGM01); // CTC mode TCCR0B = (1 << CS01); // Fcpu/8 speed |