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210 lines
6.4 KiB
210 lines
6.4 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 AudioOutput 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 "AudioOutput.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 Speaker_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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for (;;)
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{
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if (Speaker_Audio_Interface.State.InterfaceEnabled)
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ProcessNextSample();
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Audio_Device_USBTask(&Speaker_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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}
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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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if ((TIFR0 & (1 << OCF0A)) && Audio_Device_IsSampleReceived(&Speaker_Audio_Interface))
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{
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/* Clear the sample reload timer */
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TIFR0 |= (1 << OCF0A);
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/* Retrieve the signed 16-bit left and right audio samples */
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int16_t LeftSample_16Bit = (int16_t)Audio_Device_ReadSample16();
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int16_t RightSample_16Bit = (int16_t)Audio_Device_ReadSample16();
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/* Massage signed 16-bit left and right audio samples into signed 8-bit */
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int8_t LeftSample_8Bit = (LeftSample_16Bit >> 8);
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int8_t RightSample_8Bit = (RightSample_16Bit >> 8);
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/* Mix the two channels together to produce a mono, 8-bit sample */
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int8_t MixedSample_8Bit = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1);
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#if defined(AUDIO_OUT_MONO)
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/* Load the sample into the PWM timer channel */
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OCR3A = ((uint8_t)MixedSample_8Bit ^ (1 << 7));
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#elif defined(AUDIO_OUT_STEREO)
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/* Load the dual 8-bit samples into the PWM timer channels */
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OCR3A = ((uint8_t)LeftSample_8Bit ^ (1 << 7));
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OCR3B = ((uint8_t)RightSample_8Bit ^ (1 << 7));
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#elif defined(AUDIO_OUT_PORTC)
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/* Load the 8-bit mixed sample into PORTC */
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PORTC = MixedSample_8Bit;
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#else
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uint8_t LEDMask = LEDS_NO_LEDS;
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/* Make mixed sample value positive (absolute) */
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MixedSample_8Bit = abs(MixedSample_8Bit);
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if (MixedSample_8Bit > ((128 / 8) * 1))
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LEDMask |= LEDS_LED1;
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if (MixedSample_8Bit > ((128 / 8) * 2))
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LEDMask |= LEDS_LED2;
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if (MixedSample_8Bit > ((128 / 8) * 3))
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LEDMask |= LEDS_LED3;
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if (MixedSample_8Bit > ((128 / 8) * 4))
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LEDMask |= LEDS_LED4;
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LEDs_SetAllLEDs(LEDMask);
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#endif
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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_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 / AUDIO_SAMPLE_FREQUENCY) - 1;
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TCCR0A = (1 << WGM01); // CTC mode
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TCCR0B = (1 << CS00); // Fcpu speed
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#if defined(AUDIO_OUT_MONO)
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/* Set speaker as output */
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DDRC |= (1 << 6);
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#elif defined(AUDIO_OUT_STEREO)
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/* Set speakers as outputs */
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DDRC |= ((1 << 6) | (1 << 5));
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#elif defined(AUDIO_OUT_PORTC)
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/* Set PORTC as outputs */
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DDRC |= 0xFF;
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#endif
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#if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
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/* PWM speaker timer initialization */
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TCCR3A = ((1 << WGM30) | (1 << COM3A1) | (1 << COM3A0)
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| (1 << COM3B1) | (1 << COM3B0)); // Set on match, clear on TOP
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TCCR3B = ((1 << WGM32) | (1 << CS30)); // Fast 8-Bit PWM, Fcpu speed
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#endif
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}
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/** Event handler for the library USB Disconnection event. */
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void EVENT_USB_Disconnect(void)
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{
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LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
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/* Stop the sample reload timer */
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TCCR0B = 0;
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#if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
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/* Stop the PWM generation timer */
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TCCR3B = 0;
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#endif
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#if defined(AUDIO_OUT_MONO)
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/* Set speaker as input to reduce current draw */
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DDRC &= ~(1 << 6);
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#elif defined(AUDIO_OUT_STEREO)
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/* Set speakers as inputs to reduce current draw */
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DDRC &= ~((1 << 6) | (1 << 5));
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#elif defined(AUDIO_OUT_PORTC)
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/* Set PORTC low */
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PORTC = 0x00;
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#endif
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}
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/** Event handler for the library USB Configuration Changed event. */
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void EVENT_USB_ConfigurationChanged(void)
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{
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LEDs_SetAllLEDs(LEDMASK_USB_READY);
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if (!(Audio_Device_ConfigureEndpoints(&Speaker_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 Packet event. */
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void EVENT_USB_UnhandledControlPacket(void)
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{
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Audio_Device_ProcessControlPacket(&Speaker_Audio_Interface);
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}
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