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