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

[pub/USBasp.git] / Demos / Device / LowLevel / AudioInput / AudioInput.c

diff --git a/Demos/Device/LowLevel/AudioInput/AudioInput.c b/Demos/Device/LowLevel/AudioInput/AudioInput.c
index a984a2a..e681f3b 100644 (file)
--- 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);