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/*
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.
*/
#include "AudioInput.h"
USB_ClassInfo_Audio_t Microphone_Audio_Interface =
{
.InterfaceNumber = 0,
.DataINEndpointNumber = AUDIO_STREAM_EPNUM,
.DataINEndpointSize = AUDIO_STREAM_EPSIZE,
};
int main(void)
{
SetupHardware();
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
for (;;)
{
if (Microphone_Audio_Interface.InterfaceEnabled)
ProcessNextSample();
USB_USBTask();
}
}
void SetupHardware(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();
USB_Init();
ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
ADC_SetupChannel(MIC_IN_ADC_CHANNEL);
/* Start the ADC conversion in free running mode */
ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | MIC_IN_ADC_CHANNEL);
}
void ProcessNextSample(void)
{
if ((TIFR0 & (1 << OCF0A)) && USB_Audio_IsReadyForNextSample(&Microphone_Audio_Interface))
{
TIFR0 |= (1 << OCF0A);
/* Audio sample is ADC value scaled to fit the entire range */
int16_t AudioSample = ((SAMPLE_MAX_RANGE / ADC_MAX_RANGE) * ADC_GetResult());
#if defined(MICROPHONE_BIASED_TO_HALF_RAIL)
/* Microphone is biased to half rail voltage, subtract the bias from the sample value */
AudioSample -= (SAMPLE_MAX_RANGE / 2));
#endif
USB_Audio_WriteSample16(AudioSample);
}
}
void EVENT_USB_Connect(void)
{
LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
/* Sample reload timer initialization */
OCR0A = (F_CPU / AUDIO_SAMPLE_FREQUENCY) - 1;
TCCR0A = (1 << WGM01); // CTC mode
TCCR0B = (1 << CS00); // Fcpu speed
}
void EVENT_USB_Disconnect(void)
{
/* Stop the sample reload timer */
TCCR0B = 0;
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
}
void EVENT_USB_ConfigurationChanged(void)
{
LEDs_SetAllLEDs(LEDMASK_USB_READY);
if (!(USB_Audio_ConfigureEndpoints(&Microphone_Audio_Interface)))
LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
}
void EVENT_USB_UnhandledControlPacket(void)
{
USB_Audio_ProcessControlPacket(&Microphone_Audio_Interface);
}
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