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232 lines
7.4 KiB
232 lines
7.4 KiB
/*
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LUFA Library
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Copyright (C) Dean Camera, 2009.
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dean [at] fourwalledcubicle [dot] com
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www.fourwalledcubicle.com
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*/
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/*
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Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)
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Permission to use, copy, modify, and distribute this software
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and its documentation for any purpose and without fee is hereby
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granted, provided that the above copyright notice appear in all
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copies and that both that the copyright notice and this
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permission notice and warranty disclaimer appear in supporting
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documentation, and that the name of the author not be used in
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advertising or publicity pertaining to distribution of the
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software without specific, written prior permission.
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The author disclaim all warranties with regard to this
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software, including all implied warranties of merchantability
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and fitness. In no event shall the author be liable for any
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special, indirect or consequential damages or any damages
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whatsoever resulting from loss of use, data or profits, whether
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in an action of contract, negligence or other tortious action,
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arising out of or in connection with the use or performance of
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this software.
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*/
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/** \file
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*
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* Main source file for the Audio Input demo. This file contains the main tasks of the demo and
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* is responsible for the initial application hardware configuration.
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*/
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/* --- Project Configuration --- */
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//#define MICROPHONE_BIASED_TO_HALF_RAIL
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/* --- --- --- --- --- --- --- --- */
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#include "AudioInput.h"
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/* Project Tags, for reading out using the ButtLoad project */
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BUTTLOADTAG(ProjName, "LUFA AudioIn App");
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BUTTLOADTAG(BuildTime, __TIME__);
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BUTTLOADTAG(BuildDate, __DATE__);
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BUTTLOADTAG(LUFAVersion, "LUFA V" LUFA_VERSION_STRING);
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/* Scheduler Task List */
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TASK_LIST
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{
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{ Task: USB_USBTask , TaskStatus: TASK_STOP },
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{ Task: USB_Audio_Task , TaskStatus: TASK_STOP },
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};
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/** Main program entry point. This routine configures the hardware required by the application, then
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* starts the scheduler to run the application tasks.
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*/
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int main(void)
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{
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/* Disable watchdog if enabled by bootloader/fuses */
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MCUSR &= ~(1 << WDRF);
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wdt_disable();
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/* Disable Clock Division */
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SetSystemClockPrescaler(0);
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/* Hardware Initialization */
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LEDs_Init();
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ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
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ADC_SetupChannel(MIC_IN_ADC_CHANNEL);
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/* Start the ADC conversion in free running mode */
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ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | MIC_IN_ADC_CHANNEL);
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/* Indicate USB not ready */
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UpdateStatus(Status_USBNotReady);
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/* Initialize Scheduler so that it can be used */
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Scheduler_Init();
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/* Initialize USB Subsystem */
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USB_Init();
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/* Scheduling - routine never returns, so put this last in the main function */
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Scheduler_Start();
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}
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/** Event handler for the USB_Connect event. This indicates that the device is enumerating via the status LEDs, and
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* configures the sample update and PWM timers.
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*/
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EVENT_HANDLER(USB_Connect)
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{
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/* Start USB management task */
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Scheduler_SetTaskMode(USB_USBTask, TASK_RUN);
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/* Indicate USB enumerating */
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UpdateStatus(Status_USBEnumerating);
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/* Sample reload timer initialization */
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OCR0A = (F_CPU / AUDIO_SAMPLE_FREQUENCY);
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TCCR0A = (1 << WGM01); // CTC mode
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TCCR0B = (1 << CS00); // Fcpu speed
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}
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/** Event handler for the USB_Disconnect event. This indicates that the device is no longer connected to a host via
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* the status LEDs, disables the sample update and PWM output timers and stops the USB and Audio management tasks.
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*/
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EVENT_HANDLER(USB_Disconnect)
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{
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/* Stop the sample reload timer */
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TCCR0B = 0;
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/* Stop running audio and USB management tasks */
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Scheduler_SetTaskMode(USB_Audio_Task, TASK_STOP);
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Scheduler_SetTaskMode(USB_USBTask, TASK_STOP);
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/* Indicate USB not ready */
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UpdateStatus(Status_USBNotReady);
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}
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/** Event handler for the USB_ConfigurationChanged event. This is fired when the host set the current configuration
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* of the USB device after enumeration - the device endpoints are configured.
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*/
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EVENT_HANDLER(USB_ConfigurationChanged)
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{
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/* Setup audio stream endpoint */
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Endpoint_ConfigureEndpoint(AUDIO_STREAM_EPNUM, EP_TYPE_ISOCHRONOUS,
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ENDPOINT_DIR_IN, AUDIO_STREAM_EPSIZE,
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ENDPOINT_BANK_DOUBLE);
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/* Indicate USB connected and ready */
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UpdateStatus(Status_USBReady);
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}
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/** Event handler for the USB_UnhandledControlPacket event. This is used to catch standard and class specific
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* control requests that are not handled internally by the USB library (including the Audio class-specific
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* requests) so that they can be handled appropriately for the application.
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*/
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EVENT_HANDLER(USB_UnhandledControlPacket)
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{
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/* Process General and Audio specific control requests */
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switch (bRequest)
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{
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case REQ_SetInterface:
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/* Set Interface is not handled by the library, as its function is application-specific */
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if (bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_STANDARD | REQREC_INTERFACE))
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{
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uint16_t wValue = Endpoint_Read_Word_LE();
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Endpoint_ClearSetupReceived();
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/* Check if the host is enabling the audio interface (setting AlternateSetting to 1) */
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if (wValue)
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{
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/* Start audio task */
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Scheduler_SetTaskMode(USB_Audio_Task, TASK_RUN);
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}
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else
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{
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/* Stop audio task */
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Scheduler_SetTaskMode(USB_Audio_Task, TASK_STOP);
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}
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/* Handshake the request */
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Endpoint_ClearSetupIN();
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}
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break;
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}
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}
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/** Function to manage status updates to the user. This is done via LEDs on the given board, if available, but may be changed to
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* log to a serial port, or anything else that is suitable for status updates.
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*
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* \param CurrentStatus Current status of the system, from the AudioInput_StatusCodes_t enum
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*/
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void UpdateStatus(uint8_t CurrentStatus)
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{
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uint8_t LEDMask = LEDS_NO_LEDS;
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/* Set the LED mask to the appropriate LED mask based on the given status code */
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switch (CurrentStatus)
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{
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case Status_USBNotReady:
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LEDMask = (LEDS_LED1);
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break;
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case Status_USBEnumerating:
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LEDMask = (LEDS_LED1 | LEDS_LED2);
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break;
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case Status_USBReady:
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LEDMask = (LEDS_LED2 | LEDS_LED4);
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break;
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}
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/* Set the board LEDs to the new LED mask */
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LEDs_SetAllLEDs(LEDMask);
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}
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/** Task to manage the Audio interface, reading in ADC samples from the microphone, and them to the host. */
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TASK(USB_Audio_Task)
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{
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/* Select the audio stream endpoint */
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Endpoint_SelectEndpoint(AUDIO_STREAM_EPNUM);
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/* Check if the current endpoint can be read from (contains a packet) and that the next sample should be stored */
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if (Endpoint_ReadWriteAllowed() && (TIFR0 & (1 << OCF0A)))
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{
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/* Clear the sample reload timer */
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TIFR0 |= (1 << OCF0A);
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/* Audio sample is ADC value scaled to fit the entire range */
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int16_t AudioSample = ((SAMPLE_MAX_RANGE / ADC_MAX_RANGE) * ADC_GetResult());
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#if defined(MICROPHONE_BIASED_TO_HALF_RAIL)
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/* Microphone is biased to half rail voltage, subtract the bias from the sample value */
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AudioSample -= (SAMPLE_MAX_RANGE / 2));
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#endif
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/* Write the sample to the buffer */
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Endpoint_Write_Word_LE(AudioSample);
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/* Check to see if the bank is now full */
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if (!(Endpoint_ReadWriteAllowed()))
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{
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/* Send the full packet to the host */
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Endpoint_ClearCurrentBank();
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}
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}
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}
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