summaryrefslogtreecommitdiff
path: root/digital/avr/modules/usb/lufa/Demos/AudioOutput/AudioOutput.c
diff options
context:
space:
mode:
Diffstat (limited to 'digital/avr/modules/usb/lufa/Demos/AudioOutput/AudioOutput.c')
-rw-r--r--digital/avr/modules/usb/lufa/Demos/AudioOutput/AudioOutput.c305
1 files changed, 305 insertions, 0 deletions
diff --git a/digital/avr/modules/usb/lufa/Demos/AudioOutput/AudioOutput.c b/digital/avr/modules/usb/lufa/Demos/AudioOutput/AudioOutput.c
new file mode 100644
index 00000000..184910e8
--- /dev/null
+++ b/digital/avr/modules/usb/lufa/Demos/AudioOutput/AudioOutput.c
@@ -0,0 +1,305 @@
+/*
+ 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.
+ */
+
+/* --- Project Configuration (Choose ONE) --- */
+//#define AUDIO_OUT_MONO
+#define AUDIO_OUT_STEREO
+//#define AUDIO_OUT_LEDS
+//#define AUDIO_OUT_PORTC
+/* --- --- --- --- --- --- --- --- --- --- --- */
+
+#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 */
+ SetSystemClockPrescaler(0);
+
+ /* 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);
+ }
+
+ /* Handshake the request */
+ 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()))
+ {
+ /* Acknowedge 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
+ }
+}