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Added default test tone generation mode to the Device mode AudioInput demos.

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This commit is contained in:
Dean Camera 2010-10-20 07:39:11 +00:00
parent 06f222b3ed
commit bd337aced3
10 changed files with 75 additions and 23 deletions
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29
Demos/Device/ClassDriver/AudioInput/AudioInput.c
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@ -82,9 +82,10 @@ void SetupHardware(void)
/* Hardware Initialization */
LEDs_Init();
USB_Init();
Buttons_Init();
ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
ADC_SetupChannel(MIC_IN_ADC_CHANNEL);
USB_Init();
/* Start the ADC conversion in free running mode */
ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | MIC_IN_ADC_MUX_MASK);
@ -100,15 +101,29 @@ void ProcessNextSample(void)
{
/* Clear the sample reload timer compare flag, ready for the next interval */
TIFR0 |= (1 << OCF0A);
int16_t AudioSample;
/* Audio sample is ADC value scaled to fit the entire range */
int16_t AudioSample = ((SAMPLE_MAX_RANGE / ADC_MAX_RANGE) * ADC_GetResult());
#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);
#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
#endif
Audio_Device_WriteSample16(&Microphone_Audio_Interface, AudioSample);
}
}