294 lines
10 KiB
C
294 lines
10 KiB
C
|
/*
|
||
|
|
LUFA Library
|
||
|
|
Copyright (C) Dean Camera, 2019.
|
||
|
|
|
||
|
|
dean [at] fourwalledcubicle [dot] com
|
||
|
|
www.lufa-lib.org
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
Copyright 2019 Dean Camera (dean [at] fourwalledcubicle [dot] com)
|
||
|
|
|
||
|
|
Permission to use, copy, modify, distribute, and sell this
|
||
|
|
software and its documentation for any purpose is hereby granted
|
||
|
|
without fee, 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 disclaims 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/** \file
|
||
|
|
*
|
||
|
|
* Main source file for the AudioOutput demo. This file contains the main tasks of the demo and
|
||
|
|
* is responsible for the initial application hardware configuration.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "AudioOutput.h"
|
||
|
|
|
||
|
|
/** Flag to indicate if the streaming audio alternative interface has been selected by the host. */
|
||
|
|
static bool StreamingAudioInterfaceSelected = false;
|
||
|
|
|
||
|
|
/** Current audio sampling frequency of the streaming audio endpoint. */
|
||
|
|
static uint32_t CurrentAudioSampleFrequency = 48000;
|
||
|
|
|
||
|
|
|
||
|
|
/** Main program entry point. This routine contains the overall program flow, including initial
|
||
|
|
* setup of all components and the main program loop.
|
||
|
|
*/
|
||
|
|
int main(void)
|
||
|
|
{
|
||
|
|
SetupHardware();
|
||
|
|
|
||
|
|
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
|
||
|
|
GlobalInterruptEnable();
|
||
|
|
|
||
|
|
for (;;)
|
||
|
|
{
|
||
|
|
USB_USBTask();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/** Configures the board hardware and chip peripherals for the demo's functionality. */
|
||
|
|
void SetupHardware(void)
|
||
|
|
{
|
||
|
|
#if (ARCH == ARCH_AVR8)
|
||
|
|
/* Disable watchdog if enabled by bootloader/fuses */
|
||
|
|
MCUSR &= ~(1 << WDRF);
|
||
|
|
wdt_disable();
|
||
|
|
|
||
|
|
/* Disable clock division */
|
||
|
|
clock_prescale_set(clock_div_1);
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* Hardware Initialization */
|
||
|
|
LEDs_Init();
|
||
|
|
USB_Init();
|
||
|
|
}
|
||
|
|
|
||
|
|
/** Event handler for the USB_Connect event. This indicates that the device is enumerating via the status LEDs, and
|
||
|
|
* configures the sample update and PWM timers.
|
||
|
|
*/
|
||
|
|
void EVENT_USB_Device_Connect(void)
|
||
|
|
{
|
||
|
|
/* Indicate USB enumerating */
|
||
|
|
LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
|
||
|
|
|
||
|
|
/* Sample reload timer initialization */
|
||
|
|
TIMSK0 = (1 << OCIE0A);
|
||
|
|
OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
|
||
|
|
TCCR0A = (1 << WGM01); // CTC mode
|
||
|
|
TCCR0B = (1 << CS01); // Fcpu/8 speed
|
||
|
|
|
||
|
|
#if defined(AUDIO_OUT_MONO)
|
||
|
|
/* Set speaker as output */
|
||
|
|
DDRC |= (1 << 6);
|
||
|
|
#elif defined(AUDIO_OUT_STEREO)
|
||
|
|
/* Set speakers as outputs */
|
||
|
|
DDRC |= ((1 << 6) | (1 << 5));
|
||
|
|
#elif defined(AUDIO_OUT_PORTC)
|
||
|
|
/* Set PORTC as outputs */
|
||
|
|
DDRC |= 0xFF;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
|
||
|
|
/* PWM speaker timer initialization */
|
||
|
|
TCCR3A = ((1 << WGM30) | (1 << COM3A1) | (1 << COM3A0)
|
||
|
|
| (1 << COM3B1) | (1 << COM3B0)); // Set on match, clear on TOP
|
||
|
|
TCCR3B = ((1 << WGM32) | (1 << CS30)); // Fast 8-Bit PWM, F_CPU speed
|
||
|
|
#endif
|
||
|
|
}
|
||
|
|
|
||
|
|
/** Event handler for the USB_Disconnect event. This indicates that the device is no longer connected to a host via
|
||
|
|
* the status LEDs, disables the sample update and PWM output timers and stops the USB and Audio management tasks.
|
||
|
|
*/
|
||
|
|
void EVENT_USB_Device_Disconnect(void)
|
||
|
|
{
|
||
|
|
/* Stop the timers */
|
||
|
|
TCCR0B = 0;
|
||
|
|
#if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
|
||
|
|
TCCR3B = 0;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#if defined(AUDIO_OUT_MONO)
|
||
|
|
/* Set speaker as input to reduce current draw */
|
||
|
|
DDRC &= ~(1 << 6);
|
||
|
|
#elif defined(AUDIO_OUT_STEREO)
|
||
|
|
/* Set speakers as inputs to reduce current draw */
|
||
|
|
DDRC &= ~((1 << 6) | (1 << 5));
|
||
|
|
#elif defined(AUDIO_OUT_PORTC)
|
||
|
|
/* Set PORTC low */
|
||
|
|
PORTC = 0x00;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* Indicate streaming audio interface not selected */
|
||
|
|
StreamingAudioInterfaceSelected = false;
|
||
|
|
|
||
|
|
/* Indicate USB not ready */
|
||
|
|
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
|
||
|
|
}
|
||
|
|
|
||
|
|
/** Event handler for the USB_ConfigurationChanged event. This is fired when the host set the current configuration
|
||
|
|
* of the USB device after enumeration - the device endpoints are configured.
|
||
|
|
*/
|
||
|
|
void EVENT_USB_Device_ConfigurationChanged(void)
|
||
|
|
{
|
||
|
|
bool ConfigSuccess = true;
|
||
|
|
|
||
|
|
/* Setup Audio Stream Endpoint */
|
||
|
|
ConfigSuccess &= Endpoint_ConfigureEndpoint(AUDIO_STREAM_EPADDR, EP_TYPE_ISOCHRONOUS, AUDIO_STREAM_EPSIZE, 2);
|
||
|
|
|
||
|
|
/* Indicate endpoint configuration success or failure */
|
||
|
|
LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
|
||
|
|
}
|
||
|
|
|
||
|
|
/** Event handler for the USB_ControlRequest event. This is used to catch and process control requests sent to
|
||
|
|
* the device from the USB host before passing along unhandled control requests to the library for processing
|
||
|
|
* internally.
|
||
|
|
*/
|
||
|
|
void EVENT_USB_Device_ControlRequest(void)
|
||
|
|
{
|
||
|
|
/* Process General and Audio specific control requests */
|
||
|
|
switch (USB_ControlRequest.bRequest)
|
||
|
|
{
|
||
|
|
case REQ_SetInterface:
|
||
|
|
/* Set Interface is not handled by the library, as its function is application-specific */
|
||
|
|
if (USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_STANDARD | REQREC_INTERFACE))
|
||
|
|
{
|
||
|
|
Endpoint_ClearSETUP();
|
||
|
|
Endpoint_ClearStatusStage();
|
||
|
|
|
||
|
|
/* Check if the host is enabling the audio interface (setting AlternateSetting to 1) */
|
||
|
|
StreamingAudioInterfaceSelected = ((USB_ControlRequest.wValue) != 0);
|
||
|
|
}
|
||
|
|
|
||
|
|
break;
|
||
|
|
case AUDIO_REQ_GetStatus:
|
||
|
|
/* Get Status request can be directed at either the interface or endpoint, neither is currently used
|
||
|
|
* according to the latest USB Audio 1.0 standard, but must be ACKed with no data when requested */
|
||
|
|
if ((USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_INTERFACE)) ||
|
||
|
|
(USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_ENDPOINT)))
|
||
|
|
{
|
||
|
|
Endpoint_ClearSETUP();
|
||
|
|
Endpoint_ClearStatusStage();
|
||
|
|
}
|
||
|
|
|
||
|
|
break;
|
||
|
|
case AUDIO_REQ_SetCurrent:
|
||
|
|
if (USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_ENDPOINT))
|
||
|
|
{
|
||
|
|
/* Extract out the relevant request information to get the target Endpoint address and control being set */
|
||
|
|
uint8_t EndpointAddress = (uint8_t)USB_ControlRequest.wIndex;
|
||
|
|
uint8_t EndpointControl = (USB_ControlRequest.wValue >> 8);
|
||
|
|
|
||
|
|
/* Only handle SET CURRENT requests to the audio endpoint's sample frequency property */
|
||
|
|
if ((EndpointAddress == AUDIO_STREAM_EPADDR) && (EndpointControl == AUDIO_EPCONTROL_SamplingFreq))
|
||
|
|
{
|
||
|
|
uint8_t SampleRate[3];
|
||
|
|
|
||
|
|
Endpoint_ClearSETUP();
|
||
|
|
Endpoint_Read_Control_Stream_LE(SampleRate, sizeof(SampleRate));
|
||
|
|
Endpoint_ClearIN();
|
||
|
|
|
||
|
|
/* Set the new sampling frequency to the value given by the host */
|
||
|
|
CurrentAudioSampleFrequency = (((uint32_t)SampleRate[2] << 16) | ((uint32_t)SampleRate[1] << 8) | (uint32_t)SampleRate[0]);
|
||
|
|
|
||
|
|
/* Adjust sample reload timer to the new frequency */
|
||
|
|
OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
break;
|
||
|
|
case AUDIO_REQ_GetCurrent:
|
||
|
|
if (USB_ControlRequest.bmRequestType == (REQDIR_DEVICETOHOST | REQTYPE_CLASS | REQREC_ENDPOINT))
|
||
|
|
{
|
||
|
|
/* Extract out the relevant request information to get the target Endpoint address and control being retrieved */
|
||
|
|
uint8_t EndpointAddress = (uint8_t)USB_ControlRequest.wIndex;
|
||
|
|
uint8_t EndpointControl = (USB_ControlRequest.wValue >> 8);
|
||
|
|
|
||
|
|
/* Only handle GET CURRENT requests to the audio endpoint's sample frequency property */
|
||
|
|
if ((EndpointAddress == AUDIO_STREAM_EPADDR) && (EndpointControl == AUDIO_EPCONTROL_SamplingFreq))
|
||
|
|
{
|
||
|
|
uint8_t SampleRate[3];
|
||
|
|
|
||
|
|
/* Convert the sampling rate value into the 24-bit format the host expects for the property */
|
||
|
|
SampleRate[2] = (CurrentAudioSampleFrequency >> 16);
|
||
|
|
SampleRate[1] = (CurrentAudioSampleFrequency >> 8);
|
||
|
|
SampleRate[0] = (CurrentAudioSampleFrequency & 0xFF);
|
||
|
|
|
||
|
|
Endpoint_ClearSETUP();
|
||
|
|
Endpoint_Write_Control_Stream_LE(SampleRate, sizeof(SampleRate));
|
||
|
|
Endpoint_ClearOUT();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/** ISR to handle the reloading of the PWM timer with the next sample. */
|
||
|
|
ISR(TIMER0_COMPA_vect, ISR_BLOCK)
|
||
|
|
{
|
||
|
|
uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
|
||
|
|
|
||
|
|
/* Select the audio stream endpoint */
|
||
|
|
Endpoint_SelectEndpoint(AUDIO_STREAM_EPADDR);
|
||
|
|
|
||
|
|
/* Check if the current endpoint can be read from (contains a packet) and the host is sending data */
|
||
|
|
if (Endpoint_IsOUTReceived() && StreamingAudioInterfaceSelected)
|
||
|
|
{
|
||
|
|
/* Retrieve the signed 16-bit left and right audio samples, convert to 8-bit */
|
||
|
|
int8_t LeftSample_8Bit = ((int16_t)Endpoint_Read_16_LE() >> 8);
|
||
|
|
int8_t RightSample_8Bit = ((int16_t)Endpoint_Read_16_LE() >> 8);
|
||
|
|
|
||
|
|
/* Mix the two channels together to produce a mono, 8-bit sample */
|
||
|
|
int8_t MixedSample_8Bit = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1);
|
||
|
|
|
||
|
|
/* Check to see if the bank is now empty */
|
||
|
|
if (!(Endpoint_IsReadWriteAllowed()))
|
||
|
|
{
|
||
|
|
/* Acknowledge the packet, clear the bank ready for the next packet */
|
||
|
|
Endpoint_ClearOUT();
|
||
|
|
}
|
||
|
|
|
||
|
|
#if defined(AUDIO_OUT_MONO)
|
||
|
|
/* Load the sample into the PWM timer channel */
|
||
|
|
OCR3A = (MixedSample_8Bit ^ (1 << 7));
|
||
|
|
#elif defined(AUDIO_OUT_STEREO)
|
||
|
|
/* Load the dual 8-bit samples into the PWM timer channels */
|
||
|
|
OCR3A = (LeftSample_8Bit ^ (1 << 7));
|
||
|
|
OCR3B = (RightSample_8Bit ^ (1 << 7));
|
||
|
|
#elif defined(AUDIO_OUT_PORTC)
|
||
|
|
/* Load the 8-bit mixed sample into PORTC */
|
||
|
|
PORTC = MixedSample_8Bit;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
uint8_t LEDMask = LEDS_NO_LEDS;
|
||
|
|
|
||
|
|
/* Turn on LEDs as the sample amplitude increases */
|
||
|
|
if (MixedSample_8Bit > 16)
|
||
|
|
LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3 | LEDS_LED4);
|
||
|
|
else if (MixedSample_8Bit > 8)
|
||
|
|
LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3);
|
||
|
|
else if (MixedSample_8Bit > 4)
|
||
|
|
LEDMask = (LEDS_LED1 | LEDS_LED2);
|
||
|
|
else if (MixedSample_8Bit > 2)
|
||
|
|
LEDMask = (LEDS_LED1);
|
||
|
|
|
||
|
|
LEDs_SetAllLEDs(LEDMask);
|
||
|
|
}
|
||
|
|
|
||
|
|
Endpoint_SelectEndpoint(PrevEndpoint);
|
||
|
|
}
|
||
|
|
|