@ -28,16 +28,29 @@
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"
/** LUFA Audio Class driver interface configuration and state information. This structure is
* passed to all Audio Class driver functions , so that multiple instances of the same class
* within a device can be differentiated from one another .
*/
USB_ClassInfo_Audio_t Speaker_Audio_Interface =
{
. InterfaceNumber = 0 ,
. StreamingInterfaceNumber = 1 ,
. DataOUTEndpointNumber = AUDIO_STREAM_EPNUM ,
. DataOUTEndpointSize = AUDIO_STREAM_EPSIZE ,
} ;
/** 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 ( ) ;
@ -53,6 +66,7 @@ int main(void)
}
}
/** Configures the board hardware and chip peripherals for the demo's functionality. */
void SetupHardware ( void )
{
/* Disable watchdog if enabled by bootloader/fuses */
@ -67,6 +81,9 @@ void SetupHardware(void)
USB_Init ( ) ;
}
/** Processes the next audio sample by reading the last ADC conversion and writing it to the audio
* interface , each time the sample reload timer period elapses to give a constant sample rate .
*/
void ProcessNextSample ( void )
{
if ( ( TIFR0 & ( 1 < < OCF0A ) ) & & USB_Audio_IsSampleReceived ( & Speaker_Audio_Interface ) )
@ -82,10 +99,10 @@ void ProcessNextSample(void)
int8_t LeftSample_8Bit = ( LeftSample_16Bit > > 8 ) ;
int8_t RightSample_8Bit = ( RightSample_16Bit > > 8 ) ;
# if defined(AUDIO_OUT_MONO)
/* 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 ) ;
# if defined(AUDIO_OUT_MONO)
/* Load the sample into the PWM timer channel */
OCRxA = ( ( uint8_t ) MixedSample_8Bit ^ ( 1 < < 7 ) ) ;
# elif defined(AUDIO_OUT_STEREO)
@ -93,42 +110,32 @@ void ProcessNextSample(void)
OCRxA = ( ( uint8_t ) LeftSample_8Bit ^ ( 1 < < 7 ) ) ;
OCRxB = ( ( uint8_t ) RightSample_8Bit ^ ( 1 < < 7 ) ) ;
# elif defined(AUDIO_OUT_PORTC)
/* 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 ) ;
PORTC = MixedSample_8Bit ;
# else
uint8_t LEDMask = LEDS_NO_LEDS ;
/* Make left channel positive (absolute) */
if ( Left Sample_8Bit < 0 )
LeftSample_8Bit = - Left Sample_8Bit;
/* Make mixed sample value positive (absolute) */
if ( Mixed Sample_8Bit < 0 )
MixedSample_8Bit = - Mixed Sample_8Bit;
/* Make right channel positive (absolute) */
if ( RightSample_8Bit < 0 )
RightSample_8Bit = - RightSample_8Bit ;
if ( MixedSample_8Bit > ( ( 128 / 8 ) * 1 ) )
LEDMask | = LEDS_LED1 ;
/* Set first LED based on sample value */
if ( LeftSample_8Bit < ( ( 128 / 8 ) * 1 ) )
if ( MixedSample_8Bit > ( ( 128 / 8 ) * 2 ) )
LEDMask | = LEDS_LED2 ;
else if ( LeftSample_8Bit < ( ( 128 / 8 ) * 3 ) )
LEDMask | = ( LEDS_LED1 | LEDS_LED2 ) ;
else
LEDMask | = LEDS_LED1 ;
/* Set second LED based on sample value */
if ( RightSample_8Bit < ( ( 128 / 8 ) * 1 ) )
LEDMask | = LEDS_LED4 ;
else if ( RightSample_8Bit < ( ( 128 / 8 ) * 3 ) )
LEDMask | = ( LEDS_LED3 | LEDS_LED4 ) ;
else
if ( MixedSample_8Bit > ( ( 128 / 8 ) * 3 ) )
LEDMask | = LEDS_LED3 ;
if ( MixedSample_8Bit > ( ( 128 / 8 ) * 4 ) )
LEDMask | = LEDS_LED4 ;
LEDs_SetAllLEDs ( LEDMask ) ;
# endif
}
}
/** Event handler for the library USB Connection event. */
void EVENT_USB_Connect ( void )
{
LEDs_SetAllLEDs ( LEDMASK_USB_ENUMERATING ) ;
@ -157,16 +164,16 @@ void EVENT_USB_Connect(void)
# 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 .
*/
/** Event handler for the library USB Disconnection event. */
void EVENT_USB_Disconnect ( void )
{
LEDs_SetAllLEDs ( LEDMASK_USB_NOTREADY ) ;
/* Stop the timers */
/* Stop the sample reload timer */
TCCR0B = 0 ;
# if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
/* Stop the PWM generation timer */
TCCRxB = 0 ;
# endif
@ -182,6 +189,7 @@ void EVENT_USB_Disconnect(void)
# endif
}
/** Event handler for the library USB Configuration Changed event. */
void EVENT_USB_ConfigurationChanged ( void )
{
LEDs_SetAllLEDs ( LEDMASK_USB_READY ) ;
@ -190,6 +198,7 @@ void EVENT_USB_ConfigurationChanged(void)
LEDs_SetAllLEDs ( LEDMASK_USB_ERROR ) ;
}
/** Event handler for the library USB Unhandled Control Packet event. */
void EVENT_USB_UnhandledControlPacket ( void )
{
USB_Audio_ProcessControlPacket ( & Speaker_Audio_Interface ) ;
Dean Camera
16 years ago