X-Git-Url: http://git.linex4red.de/pub/lufa.git/blobdiff_plain/ecf7538430c01b95104682f0f7493e57b9168125..ed031c1df2f5b053b9cd9f48c63e66a42b7c049e:/Demos/Device/AudioOutput/AudioOutput.c?ds=sidebyside

diff --git a/Demos/Device/AudioOutput/AudioOutput.c b/Demos/Device/AudioOutput/AudioOutput.c
new file mode 100644
index 000000000..0f390f001
--- /dev/null
+++ b/Demos/Device/AudioOutput/AudioOutput.c
@@ -0,0 +1,299 @@
+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2009.
+              
+  dean [at] fourwalledcubicle [dot] com
+      www.fourwalledcubicle.com
+*/
+
+/*
+  Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, and distribute this software
+  and its documentation for any purpose and without fee is hereby
+  granted, provided that the above copyright notice appear in all
+  copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \file
+ *
+ *  Main source file for the Audio Output demo. This file contains the main tasks of the demo and
+ *  is responsible for the initial application hardware configuration.
+ */
+ 
+#include "AudioOutput.h"
+
+/* Project Tags, for reading out using the ButtLoad project */
+BUTTLOADTAG(ProjName,    "LUFA AudioOut App");
+BUTTLOADTAG(BuildTime,   __TIME__);
+BUTTLOADTAG(BuildDate,   __DATE__);
+BUTTLOADTAG(LUFAVersion, "LUFA V" LUFA_VERSION_STRING);
+
+/* Scheduler Task List */
+TASK_LIST
+{
+	{ Task: USB_USBTask          , TaskStatus: TASK_STOP },
+	{ Task: USB_Audio_Task       , TaskStatus: TASK_STOP },
+};
+
+
+/** Main program entry point. This routine configures the hardware required by the application, then
+ *  starts the scheduler to run the application tasks.
+ */
+int main(void)
+{
+	/* Disable watchdog if enabled by bootloader/fuses */
+	MCUSR &= ~(1 << WDRF);
+	wdt_disable();
+
+	/* Disable clock division */
+	clock_prescale_set(clock_div_1);
+
+	/* Hardware Initialization */
+	LEDs_Init();
+	
+	/* Indicate USB not ready */
+	UpdateStatus(Status_USBNotReady);
+	
+	/* Initialize Scheduler so that it can be used */
+	Scheduler_Init();
+
+	/* Initialize USB Subsystem */
+	USB_Init();
+
+	/* Scheduling - routine never returns, so put this last in the main function */
+	Scheduler_Start();
+}
+
+/** Event handler for the USB_Connect event. This indicates that the device is enumerating via the status LEDs, and
+ *  configures the sample update and PWM timers.
+ */
+EVENT_HANDLER(USB_Connect)
+{
+	/* Start USB management task */
+	Scheduler_SetTaskMode(USB_USBTask, TASK_RUN);
+
+	/* Indicate USB enumerating */
+	UpdateStatus(Status_USBEnumerating);
+	
+	/* Sample reload timer initialization */
+	OCR0A   = (F_CPU / AUDIO_SAMPLE_FREQUENCY);
+	TCCR0A  = (1 << WGM01);  // CTC mode
+	TCCR0B  = (1 << CS00);   // Fcpu speed
+			
+#if defined(AUDIO_OUT_MONO)
+	/* Set speaker as output */
+	DDRC   |= (1 << 6);
+#elif defined(AUDIO_OUT_STEREO)
+	/* Set speakers as outputs */
+	DDRC   |= ((1 << 6) | (1 << 5));
+#elif defined(AUDIO_OUT_PORTC)
+	/* Set PORTC as outputs */
+	DDRC   |= 0xFF;
+#endif
+
+#if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
+	/* PWM speaker timer initialization */
+	TCCRxA  = ((1 << WGMx0) | (1 << COMxA1) | (1 << COMxA0)
+							| (1 << COMxB1) | (1 << COMxB0)); // Set on match, clear on TOP
+	TCCRxB  = ((1 << WGMx2) | (1 << CSx0));  // Fast 8-Bit PWM, Fcpu speed
+#endif	
+}
+
+/** Event handler for the USB_Disconnect event. This indicates that the device is no longer connected to a host via
+ *  the status LEDs, disables the sample update and PWM output timers and stops the USB and Audio management tasks.
+ */
+EVENT_HANDLER(USB_Disconnect)
+{
+	/* Stop the timers */
+	TCCR0B = 0;
+#if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
+	TCCRxB = 0;
+#endif		
+
+#if defined(AUDIO_OUT_MONO)
+	/* Set speaker as input to reduce current draw */
+	DDRC   &= ~(1 << 6);
+#elif defined(AUDIO_OUT_STEREO)
+	/* Set speakers as inputs to reduce current draw */
+	DDRC   &= ~((1 << 6) | (1 << 5));
+#elif defined(AUDIO_OUT_PORTC)
+	/* Set PORTC low */
+	PORTC  = 0x00;
+#endif
+
+	/* Stop running audio and USB management tasks */
+	Scheduler_SetTaskMode(USB_Audio_Task, TASK_STOP);
+	Scheduler_SetTaskMode(USB_USBTask, TASK_STOP);
+
+	/* Indicate USB not ready */
+	UpdateStatus(Status_USBNotReady);
+}
+
+/** Event handler for the USB_ConfigurationChanged event. This is fired when the host set the current configuration
+ *  of the USB device after enumeration - the device endpoints are configured.
+ */
+EVENT_HANDLER(USB_ConfigurationChanged)
+{
+	/* Setup audio stream endpoint */
+	Endpoint_ConfigureEndpoint(AUDIO_STREAM_EPNUM, EP_TYPE_ISOCHRONOUS,
+		                       ENDPOINT_DIR_OUT, AUDIO_STREAM_EPSIZE,
+	                           ENDPOINT_BANK_DOUBLE);
+
+	/* Indicate USB connected and ready */
+	UpdateStatus(Status_USBReady);
+}
+
+/** Event handler for the USB_UnhandledControlPacket 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(USB_UnhandledControlPacket)
+{
+	/* Process General and Audio specific control requests */
+	switch (bRequest)
+	{
+		case REQ_SetInterface:
+			/* Set Interface is not handled by the library, as its function is application-specific */
+			if (bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_STANDARD | REQREC_INTERFACE))
+			{
+				uint16_t wValue = Endpoint_Read_Word_LE();
+				
+				Endpoint_ClearSetupReceived();
+				
+				/* Check if the host is enabling the audio interface (setting AlternateSetting to 1) */
+				if (wValue)
+				{
+					/* Start audio task */
+					Scheduler_SetTaskMode(USB_Audio_Task, TASK_RUN);
+				}
+				else
+				{
+					/* Stop audio task */
+					Scheduler_SetTaskMode(USB_Audio_Task, TASK_STOP);				
+				}
+				
+				/* Acknowledge status stage */
+				while (!(Endpoint_IsSetupINReady()));
+				Endpoint_ClearSetupIN();
+			}
+
+			break;
+	}
+}
+
+/** Function to manage status updates to the user. This is done via LEDs on the given board, if available, but may be changed to
+ *  log to a serial port, or anything else that is suitable for status updates.
+ *
+ *  \param CurrentStatus  Current status of the system, from the AudioOutput_StatusCodes_t enum
+ */
+void UpdateStatus(uint8_t CurrentStatus)
+{
+	uint8_t LEDMask = LEDS_NO_LEDS;
+	
+	/* Set the LED mask to the appropriate LED mask based on the given status code */
+	switch (CurrentStatus)
+	{
+		case Status_USBNotReady:
+			LEDMask = (LEDS_LED1);
+			break;
+		case Status_USBEnumerating:
+			LEDMask = (LEDS_LED1 | LEDS_LED2);
+			break;
+		case Status_USBReady:
+			LEDMask = (LEDS_LED2 | LEDS_LED4);
+			break;
+	}
+	
+	/* Set the board LEDs to the new LED mask */
+	LEDs_SetAllLEDs(LEDMask);
+}
+
+/** Task to manage the Audio interface, reading in audio samples from the host, and outputting them to the speakers/LEDs as
+ *  desired.
+ */
+TASK(USB_Audio_Task)
+{
+	/* Select the audio stream endpoint */
+	Endpoint_SelectEndpoint(AUDIO_STREAM_EPNUM);
+	
+	/* Check if the current endpoint can be read from (contains a packet) and that the next sample should be read */
+	if (Endpoint_ReadWriteAllowed() && (TIFR0 & (1 << OCF0A)))
+	{
+		/* Clear the sample reload timer */
+		TIFR0 |= (1 << OCF0A);
+
+		/* Retreive the signed 16-bit left and right audio samples */
+		int16_t LeftSample_16Bit  = (int16_t)Endpoint_Read_Word_LE();
+		int16_t RightSample_16Bit = (int16_t)Endpoint_Read_Word_LE();
+
+		/* Check to see if the bank is now empty */
+		if (!(Endpoint_ReadWriteAllowed()))
+		{
+			/* Acknowledge the packet, clear the bank ready for the next packet */
+			Endpoint_ClearCurrentBank();
+		}
+
+		/* Massage signed 16-bit left and right audio samples into signed 8-bit */
+		int8_t  LeftSample_8Bit   = (LeftSample_16Bit  >> 8);
+		int8_t  RightSample_8Bit  = (RightSample_16Bit >> 8);
+			
+#if defined(AUDIO_OUT_MONO)
+		/* Mix the two channels together to produce a mono, 8-bit sample */
+		int8_t  MixedSample_8Bit  = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1);
+
+		/* Load the sample into the PWM timer channel */
+		OCRxA = ((uint8_t)MixedSample_8Bit ^ (1 << 7));
+#elif defined(AUDIO_OUT_STEREO)
+		/* Load the dual 8-bit samples into the PWM timer channels */
+		OCRxA = ((uint8_t)LeftSample_8Bit  ^ (1 << 7));
+		OCRxB = ((uint8_t)RightSample_8Bit ^ (1 << 7));
+#elif defined(AUDIO_OUT_PORTC)
+		/* Mix the two channels together to produce a mono, 8-bit sample */
+		int8_t  MixedSample_8Bit  = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1);
+
+		PORTC = MixedSample_8Bit;
+#else
+		uint8_t LEDMask = LEDS_NO_LEDS;
+
+		/* Make left channel positive (absolute) */
+		if (LeftSample_8Bit < 0)
+		  LeftSample_8Bit = -LeftSample_8Bit;
+
+		/* Make right channel positive (absolute) */
+		if (RightSample_8Bit < 0)
+		  RightSample_8Bit = -RightSample_8Bit;
+
+		/* Set first LED based on sample value */
+		if (LeftSample_8Bit < ((128 / 8) * 1))
+		  LEDMask |= LEDS_LED2;
+		else if (LeftSample_8Bit < ((128 / 8) * 3))
+		  LEDMask |= (LEDS_LED1 | LEDS_LED2);
+		else
+		  LEDMask |= LEDS_LED1;
+
+		/* Set second LED based on sample value */
+		if (RightSample_8Bit < ((128 / 8) * 1))
+		  LEDMask |= LEDS_LED4;
+		else if (RightSample_8Bit < ((128 / 8) * 3))
+		  LEDMask |= (LEDS_LED3 | LEDS_LED4);
+		else
+		  LEDMask |= LEDS_LED3;
+		  
+		LEDs_SetAllLEDs(LEDMask);
+#endif
+	}
+}