/** ISR to handle the reloading of the PWM timer with the next sample. */
ISR(TIMER0_COMPA_vect, ISR_BLOCK)
{
uint8_t PrevPipe = Pipe_GetCurrentPipe();
/* Check that the USB bus is ready for the next sample to read */
if (Audio_Host_IsSampleReceived(&Microphone_Audio_Interface))
{
/* Retrieve the signed 16-bit audio sample, convert to 8-bit */
int8_t Sample_8Bit = (Audio_Host_ReadSample16(&Microphone_Audio_Interface) >> 8);
/* Load the sample into the PWM timer channel */
OCR3A = (Sample_8Bit ^ (1 << 7));
uint8_t LEDMask = LEDS_NO_LEDS;
/* Turn on LEDs as the sample amplitude increases */
if (Sample_8Bit > 16)
LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3 | LEDS_LED4);
else if (Sample_8Bit > 8)
LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3);
else if (Sample_8Bit > 4)
LEDMask = (LEDS_LED1 | LEDS_LED2);
else if (Sample_8Bit > 2)
LEDMask = (LEDS_LED1);
LEDs_SetAllLEDs(LEDMask);
}
/** ISR to handle the reloading of the PWM timer with the next sample. */
ISR(TIMER0_COMPA_vect, ISR_BLOCK)
{
uint8_t PrevPipe = Pipe_GetCurrentPipe();
/* Check that the USB bus is ready for the next sample to write */
if (Audio_Host_IsReadyForNextSample(&Speaker_Audio_Interface))
{
int16_t AudioSample;
#if defined(USE_TEST_TONE)
static uint8_t SquareWaveSampleCount;
static int16_t CurrentWaveValue;
/* In test tone mode, generate a square wave at 1/256 of the sample rate */
if (SquareWaveSampleCount++ == 0xFF)
CurrentWaveValue ^= 0x8000;
/* Only generate audio if the board button is being pressed */
AudioSample = (Buttons_GetStatus() & BUTTONS_BUTTON1) ? CurrentWaveValue : 0;
#else
/* Audio sample is ADC value scaled to fit the entire range */
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
#endif
Audio_Host_WriteSample16(&Speaker_Audio_Interface, AudioSample);
Audio_Host_WriteSample16(&Speaker_Audio_Interface, AudioSample);
}
Pipe_SelectPipe(PrevPipe);
}
static void USB_HostTask(void)
{
uint8_t PrevPipe = Pipe_GetCurrentPipe();
Pipe_SelectPipe(PIPE_CONTROLPIPE);
USB_Host_ProcessNextHostState();
Pipe_SelectPipe(PrevPipe);
}
bool Pipe_IsEndpointBound(const uint8_t EndpointAddress)
{
uint8_t PrevPipeNumber = Pipe_GetCurrentPipe();
for (uint8_t PNum = 0; PNum < PIPE_TOTAL_PIPES; PNum++)
{
Pipe_SelectPipe(PNum);
if (Pipe_IsConfigured() && (Pipe_BoundEndpointNumber() == (EndpointAddress & PIPE_EPNUM_MASK)))
return true;
}
Pipe_SelectPipe(PrevPipeNumber);
return false;
}
bool Pipe_IsEndpointBound(const uint8_t EndpointAddress)
{
uint8_t PrevPipeNumber = Pipe_GetCurrentPipe();
for (uint8_t PNum = 0; PNum < PIPE_TOTAL_PIPES; PNum++)
{
Pipe_SelectPipe(PNum);
if (!(Pipe_IsConfigured()))
continue;
if (Pipe_GetBoundEndpointAddress() == EndpointAddress)
return true;
}
Pipe_SelectPipe(PrevPipeNumber);
return false;
}
/** ISR to handle the reloading of the endpoint with the next sample. */
ISR(TIMER0_COMPA_vect, ISR_BLOCK)
{
uint8_t PrevPipe = Pipe_GetCurrentPipe();
Pipe_SelectPipe(AUDIO_DATA_OUT_PIPE);
Pipe_Unfreeze();
/* Check if the current pipe can be written to (device ready for more data) */
if (Pipe_IsOUTReady())
{
int16_t AudioSample;
#if defined(USE_TEST_TONE)
static uint8_t SquareWaveSampleCount;
static int16_t CurrentWaveValue;
/* In test tone mode, generate a square wave at 1/256 of the sample rate */
if (SquareWaveSampleCount++ == 0xFF)
CurrentWaveValue ^= 0x8000;
/* Only generate audio if the board button is being pressed */
AudioSample = (Buttons_GetStatus() & BUTTONS_BUTTON1) ? CurrentWaveValue : 0;
#else
/* Audio sample is ADC value scaled to fit the entire range */
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
#endif
Pipe_Write_16_LE(AudioSample);
Pipe_Write_16_LE(AudioSample);
if (!(Pipe_IsReadWriteAllowed()))
Pipe_ClearOUT();
}
Pipe_Freeze();
Pipe_SelectPipe(PrevPipe);
}
bool Pipe_IsEndpointBound(const uint8_t EndpointAddress)
{
uint8_t PrevPipeNumber = Pipe_GetCurrentPipe();
for (uint8_t PNum = 0; PNum < PIPE_TOTAL_PIPES; PNum++)
{
Pipe_SelectPipe(PNum);
if (!(Pipe_IsConfigured()))
continue;
uint8_t PipeToken = Pipe_GetPipeToken();
bool PipeTokenCorrect = true;
if (PipeToken != PIPE_TOKEN_SETUP)
PipeTokenCorrect = (PipeToken == ((EndpointAddress & PIPE_EPDIR_MASK) ? PIPE_TOKEN_IN : PIPE_TOKEN_OUT));
if (PipeTokenCorrect && (Pipe_BoundEndpointNumber() == (EndpointAddress & PIPE_EPNUM_MASK)))
return true;
}
Pipe_SelectPipe(PrevPipeNumber);
return false;
}
