diff options
| author | Dean Camera <dean@fourwalledcubicle.com> | 2010-10-20 07:39:11 +0000 |
|---|---|---|
| committer | Dean Camera <dean@fourwalledcubicle.com> | 2010-10-20 07:39:11 +0000 |
| commit | bd337aced3b1888373030878bf1a49367bc37ab5 (patch) | |
| tree | b2633f86bc8d5155659cc9eae31672ff3958c07e /Demos/Device/LowLevel/AudioInput/AudioInput.c | |
| parent | 06f222b3ed6f612f4ac1b21566547797d4db8013 (diff) | |
| download | lufa-bd337aced3b1888373030878bf1a49367bc37ab5.tar.gz lufa-bd337aced3b1888373030878bf1a49367bc37ab5.tar.bz2 lufa-bd337aced3b1888373030878bf1a49367bc37ab5.zip | |
Added default test tone generation mode to the Device mode AudioInput demos.
Diffstat (limited to 'Demos/Device/LowLevel/AudioInput/AudioInput.c')
| -rw-r--r-- | Demos/Device/LowLevel/AudioInput/AudioInput.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/Demos/Device/LowLevel/AudioInput/AudioInput.c b/Demos/Device/LowLevel/AudioInput/AudioInput.c index a984a2ab8..e681f3bd1 100644 --- a/Demos/Device/LowLevel/AudioInput/AudioInput.c +++ b/Demos/Device/LowLevel/AudioInput/AudioInput.c @@ -68,6 +68,7 @@ void SetupHardware(void) /* Hardware Initialization */ LEDs_Init(); + Buttons_Init(); ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32); ADC_SetupChannel(MIC_IN_ADC_CHANNEL); USB_Init(); @@ -164,13 +165,27 @@ void USB_Audio_Task(void) /* Clear the sample reload timer */ TIFR0 |= (1 << OCF0A); - /* Audio sample is ADC value scaled to fit the entire range */ - int16_t AudioSample = ((SAMPLE_MAX_RANGE / ADC_MAX_RANGE) * ADC_GetResult()); - - #if defined(MICROPHONE_BIASED_TO_HALF_RAIL) - /* Microphone is biased to half rail voltage, subtract the bias from the sample value */ - AudioSample -= (SAMPLE_MAX_RANGE / 2); - #endif + int16_t AudioSample; + + #if defined(USE_TEST_TONE) + static uint8_t SquareWaveSampleCount; + static int16_t CurrentWaveValue; + + /* In test tone mode, generate a square wave at 1/256 of the sample rate */ + if (SquareWaveSampleCount++ == 0xFF) + CurrentWaveValue ^= 0x8000; + + /* Only generate audio if the board button is being pressed */ + AudioSample = (Buttons_GetStatus() & BUTTONS_BUTTON1) ? CurrentWaveValue : 0; + #else + /* Audio sample is ADC value scaled to fit the entire range */ + AudioSample = ((SAMPLE_MAX_RANGE / ADC_MAX_RANGE) * ADC_GetResult()); + + #if defined(MICROPHONE_BIASED_TO_HALF_RAIL) + /* Microphone is biased to half rail voltage, subtract the bias from the sample value */ + AudioSample -= (SAMPLE_MAX_RANGE / 2); + #endif + #end if /* Write the sample to the buffer */ Endpoint_Write_Word_LE(AudioSample); |