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149 lines
4.6 KiB
149 lines
4.6 KiB
/*
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LUFA Library
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Copyright (C) Dean Camera, 2010.
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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 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com)
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Permission to use, copy, modify, distribute, and sell this
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software and its documentation for any purpose is hereby granted
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without fee, provided that the above copyright notice appear in
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all 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 AudioInput demo. This file contains the main tasks of
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* the demo and is responsible for the initial application hardware configuration.
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*/
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#include "AudioInput.h"
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/** LUFA Audio Class driver interface configuration and state information. This structure is
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* passed to all Audio Class driver functions, so that multiple instances of the same class
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* within a device can be differentiated from one another.
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*/
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USB_ClassInfo_Audio_Device_t Microphone_Audio_Interface =
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{
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.Config =
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{
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.StreamingInterfaceNumber = 1,
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.DataINEndpointNumber = AUDIO_STREAM_EPNUM,
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.DataINEndpointSize = AUDIO_STREAM_EPSIZE,
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},
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};
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/** Main program entry point. This routine contains the overall program flow, including initial
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* setup of all components and the main program loop.
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*/
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int main(void)
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{
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SetupHardware();
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LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
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sei();
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for (;;)
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{
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ProcessNextSample();
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Audio_Device_USBTask(&Microphone_Audio_Interface);
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USB_USBTask();
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}
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}
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/** Configures the board hardware and chip peripherals for the demo's functionality. */
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void SetupHardware(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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clock_prescale_set(clock_div_1);
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/* Hardware Initialization */
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LEDs_Init();
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USB_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_MUX_MASK);
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}
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/** Processes the next audio sample by reading the last ADC conversion and writing it to the audio
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* interface, each time the sample reload timer period elapses to give a constant sample rate.
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*/
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void ProcessNextSample(void)
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{
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/* Check if the sample reload timer period has elapsed, and that the USB bus is ready for a new sample */
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if ((TIFR0 & (1 << OCF0A)) && Audio_Device_IsReadyForNextSample(&Microphone_Audio_Interface))
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{
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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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Audio_Device_WriteSample16(&Microphone_Audio_Interface, AudioSample);
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}
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}
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/** Event handler for the library USB Connection event. */
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void EVENT_USB_Device_Connect(void)
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{
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LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
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/* Sample reload timer initialization */
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OCR0A = (F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1;
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TCCR0A = (1 << WGM01); // CTC mode
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TCCR0B = (1 << CS01); // Fcpu/8 speed
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}
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/** Event handler for the library USB Disconnection event. */
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void EVENT_USB_Device_Disconnect(void)
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{
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/* Stop the sample reload timer */
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TCCR0B = 0;
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LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
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}
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/** Event handler for the library USB Configuration Changed event. */
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void EVENT_USB_Device_ConfigurationChanged(void)
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{
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LEDs_SetAllLEDs(LEDMASK_USB_READY);
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if (!(Audio_Device_ConfigureEndpoints(&Microphone_Audio_Interface)))
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LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
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}
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/** Event handler for the library USB Unhandled Control Request event. */
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void EVENT_USB_Device_UnhandledControlRequest(void)
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{
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Audio_Device_ProcessControlRequest(&Microphone_Audio_Interface);
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}
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