X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/5a4def747897c1c6ffbe465506d846c7c686d3e9..a8b66f318dda3cc18dfcedaa3af3d01ab68b82e8:/Demos/Device/LowLevel/AudioInput/AudioInput.c?ds=inline

diff --git a/Demos/Device/LowLevel/AudioInput/AudioInput.c b/Demos/Device/LowLevel/AudioInput/AudioInput.c
index a984a2ab8..16ac90e8f 100644
--- a/Demos/Device/LowLevel/AudioInput/AudioInput.c
+++ b/Demos/Device/LowLevel/AudioInput/AudioInput.c
@@ -3,7 +3,7 @@
      Copyright (C) Dean Camera, 2010.
 
   dean [at] fourwalledcubicle [dot] com
-      www.fourwalledcubicle.com
+           www.lufa-lib.org
 */
 
 /*
@@ -51,7 +51,6 @@ int main(void)
 
 	for (;;)
 	{
-		USB_Audio_Task();
 		USB_USBTask();
 	}
 }
@@ -68,6 +67,7 @@ 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();
@@ -85,7 +85,8 @@ void EVENT_USB_Device_Connect(void)
 	LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 
 	/* Sample reload timer initialization */
-	OCR0A   = (F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1;
+	TIMSK0  = (1 << OCIE0A);
+	OCR0A   = ((F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1);
 	TCCR0A  = (1 << WGM01);  // CTC mode
 	TCCR0B  = (1 << CS01);   // Fcpu/8 speed
 }
@@ -120,11 +121,11 @@ void EVENT_USB_Device_ConfigurationChanged(void)
 	LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 }
 
-/** Event handler for the USB_UnhandledControlRequest event. This is used to catch standard and class specific
- *  control requests that are not handled internally by the USB library (including the Audio class-specific
- *  requests) so that they can be handled appropriately for the application.
+/** Event handler for the USB_ControlRequest event. This is used to catch and process control requests sent to
+ *  the device from the USB host before passing along unhandled control requests to the library for processing
+ *  internally.
  */
-void EVENT_USB_Device_UnhandledControlRequest(void)
+void EVENT_USB_Device_ControlRequest(void)
 {
 	/* Process General and Audio specific control requests */
 	switch (USB_ControlRequest.bRequest)
@@ -144,32 +145,37 @@ void EVENT_USB_Device_UnhandledControlRequest(void)
 	}
 }
 
-/** Task to manage the Audio interface, reading in ADC samples from the microphone, and them to the host. */
-void USB_Audio_Task(void)
+/** ISR to handle the reloading of the data endpoint with the next sample. */
+ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 {
-	/* Device must be connected and configured for the task to run */
-	if (USB_DeviceState != DEVICE_STATE_Configured)
-	  return;
-
-	/* Check to see if the streaming interface is selected, if not the host is not receiving audio */
-	if (!(StreamingAudioInterfaceSelected))
-	  return;
+	uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
 
 	/* Select the audio stream endpoint */
 	Endpoint_SelectEndpoint(AUDIO_STREAM_EPNUM);
 
-	/* Check if the current endpoint can be written to and that the next sample should be stored */
-	if (Endpoint_IsINReady() && (TIFR0 & (1 << OCF0A)))
+	/* Check if the current endpoint can be written to and that the audio interface is enabled */
+	if (Endpoint_IsINReady() && StreamingAudioInterfaceSelected)
 	{
-		/* 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);
+		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
 
 		/* Write the sample to the buffer */
@@ -182,5 +188,7 @@ void USB_Audio_Task(void)
 			Endpoint_ClearIN();
 		}
 	}
+
+	Endpoint_SelectEndpoint(PrevEndpoint);
 }