/*
LUFA Library
Copyright (C) Dean Camera, 2010.
-
+
dean [at] fourwalledcubicle [dot] com
- www.fourwalledcubicle.com
+ www.lufa-lib.org
*/
/*
Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com)
- Permission to use, copy, modify, distribute, and sell this
+ 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
+ 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
+ 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
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
sei();
-
+
for (;;)
{
- USB_Audio_Task();
USB_USBTask();
}
}
/* Disable clock division */
clock_prescale_set(clock_div_1);
-
+
/* Hardware Initialization */
LEDs_Init();
+ Buttons_Init();
ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
ADC_SetupChannel(MIC_IN_ADC_CHANNEL);
USB_Init();
-
+
/* Start the ADC conversion in free running mode */
ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | MIC_IN_ADC_MUX_MASK);
}
LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
/* Sample reload timer initialization */
- OCR0A = (F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1;
+ TIMSK0 = (1 << OCIE0A);
+ OCR0A = ((F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1);
TCCR0A = (1 << WGM01); // CTC mode
TCCR0B = (1 << CS01); // Fcpu/8 speed
}
LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
}
-/** Event handler for the USB_UnhandledControlRequest event. This is used to catch standard and class specific
- * control requests that are not handled internally by the USB library (including the Audio class-specific
- * requests) so that they can be handled appropriately for the application.
+/** 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_UnhandledControlRequest(void)
+void EVENT_USB_Device_ControlRequest(void)
{
/* Process General and Audio specific control requests */
switch (USB_ControlRequest.bRequest)
/* 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_ClearSETUP();
Endpoint_ClearStatusStage();
/* Check if the host is enabling the audio interface (setting AlternateSetting to 1) */
}
}
-/** Task to manage the Audio interface, reading in ADC samples from the microphone, and them to the host. */
-void USB_Audio_Task(void)
+/** ISR to handle the reloading of the data endpoint with the next sample. */
+ISR(TIMER0_COMPA_vect, ISR_BLOCK)
{
- /* Device must be connected and configured for the task to run */
- if (USB_DeviceState != DEVICE_STATE_Configured)
- return;
-
- /* Check to see if the streaming interface is selected, if not the host is not receiving audio */
- if (!(StreamingAudioInterfaceSelected))
- return;
+ uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
/* Select the audio stream endpoint */
Endpoint_SelectEndpoint(AUDIO_STREAM_EPNUM);
-
- /* Check if the current endpoint can be written to and that the next sample should be stored */
- if (Endpoint_IsINReady() && (TIFR0 & (1 << OCF0A)))
+
+ /* Check if the current endpoint can be written to and that the audio interface is enabled */
+ if (Endpoint_IsINReady() && StreamingAudioInterfaceSelected)
{
- /* Clear the sample reload timer */
- 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);
+ 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
/* Write the sample to the buffer */
Endpoint_ClearIN();
}
}
+
+ Endpoint_SelectEndpoint(PrevEndpoint);
}
+
projects / pub / USBasp.git / blobdiff