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

git-svn-id: http://lufa-lib.googlecode.com/svn/trunk@1534 d5102386-fcda-11dd-9fdb-3debd5008f28

1 files changed, 24 insertions, 9 deletions

diff --git a/Demos/Device/ClassDriver/AudioInput/AudioInput.c b/Demos/Device/ClassDriver/AudioInput/AudioInput.c
index dc7a076e..54e70f6b 100644
--- a/Demos/Device/ClassDriver/AudioInput/AudioInput.c
+++ b/Demos/Device/ClassDriver/AudioInput/AudioInput.c
@@ -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);
-
-		/* 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);
+		
+		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
 		#endif
-
+		
 		Audio_Device_WriteSample16(&Microphone_Audio_Interface, AudioSample);
 	}
 }