diff options
Diffstat (limited to 'Demos/Device/ClassDriver/AudioInput/AudioInput.c')
| -rw-r--r-- | Demos/Device/ClassDriver/AudioInput/AudioInput.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/Demos/Device/ClassDriver/AudioInput/AudioInput.c b/Demos/Device/ClassDriver/AudioInput/AudioInput.c new file mode 100644 index 000000000..93ffe0bf4 --- /dev/null +++ b/Demos/Device/ClassDriver/AudioInput/AudioInput.c @@ -0,0 +1,144 @@ +/*
+ LUFA Library
+ Copyright (C) Dean Camera, 2009.
+
+ dean [at] fourwalledcubicle [dot] com
+ www.fourwalledcubicle.com
+*/
+
+/*
+ Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+ Permission to use, copy, modify, and distribute this software
+ and its documentation for any purpose and without fee is hereby
+ granted, 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 disclaim 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 AudioInput demo. This file contains the main tasks of
+ * the demo and is responsible for the initial application hardware configuration.
+ */
+
+#include "AudioInput.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 Microphone_Audio_Interface =
+ {
+ .StreamingInterfaceNumber = 1,
+
+ .DataINEndpointNumber = AUDIO_STREAM_EPNUM,
+ .DataINEndpointSize = 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();
+
+ LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
+
+ for (;;)
+ {
+ if (Microphone_Audio_Interface.InterfaceEnabled)
+ ProcessNextSample();
+
+ USB_Audio_USBTask(&Microphone_Audio_Interface);
+ USB_USBTask();
+ }
+}
+
+/** Configures the board hardware and chip peripherals for the demo's functionality. */
+void SetupHardware(void)
+{
+ /* Disable watchdog if enabled by bootloader/fuses */
+ MCUSR &= ~(1 << WDRF);
+ wdt_disable();
+
+ /* Disable clock division */
+ clock_prescale_set(clock_div_1);
+
+ /* Hardware Initialization */
+ LEDs_Init();
+ USB_Init();
+ ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
+ ADC_SetupChannel(MIC_IN_ADC_CHANNEL);
+
+ /* Start the ADC conversion in free running mode */
+ ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | MIC_IN_ADC_CHANNEL);
+}
+
+/** 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_IsReadyForNextSample(&Microphone_Audio_Interface))
+ {
+ 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));
+#endif
+
+ USB_Audio_WriteSample16(AudioSample);
+ }
+}
+
+/** Event handler for the library USB Connection event. */
+void EVENT_USB_Connect(void)
+{
+ LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
+
+ /* Sample reload timer initialization */
+ OCR0A = (F_CPU / AUDIO_SAMPLE_FREQUENCY) - 1;
+ TCCR0A = (1 << WGM01); // CTC mode
+ TCCR0B = (1 << CS00); // Fcpu speed
+}
+
+/** Event handler for the library USB Disconnection event. */
+void EVENT_USB_Disconnect(void)
+{
+ /* Stop the sample reload timer */
+ TCCR0B = 0;
+
+ LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
+}
+
+/** Event handler for the library USB Configuration Changed event. */
+void EVENT_USB_ConfigurationChanged(void)
+{
+ LEDs_SetAllLEDs(LEDMASK_USB_READY);
+
+ if (!(USB_Audio_ConfigureEndpoints(&Microphone_Audio_Interface)))
+ LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
+}
+
+/** Event handler for the library USB Unhandled Control Packet event. */
+void EVENT_USB_UnhandledControlPacket(void)
+{
+ USB_Audio_ProcessControlPacket(&Microphone_Audio_Interface);
+}
|