summaryrefslogtreecommitdiff
path: root/lib/lufa/Demos/Device/LowLevel/AudioInput/AudioInput.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/lufa/Demos/Device/LowLevel/AudioInput/AudioInput.c')
-rw-r--r--lib/lufa/Demos/Device/LowLevel/AudioInput/AudioInput.c259
1 files changed, 259 insertions, 0 deletions
diff --git a/lib/lufa/Demos/Device/LowLevel/AudioInput/AudioInput.c b/lib/lufa/Demos/Device/LowLevel/AudioInput/AudioInput.c
new file mode 100644
index 0000000000..2cf2414663
--- /dev/null
+++ b/lib/lufa/Demos/Device/LowLevel/AudioInput/AudioInput.c
@@ -0,0 +1,259 @@
+/*
+ LUFA Library
+ Copyright (C) Dean Camera, 2017.
+
+ dean [at] fourwalledcubicle [dot] com
+ www.lufa-lib.org
+*/
+
+/*
+ Copyright 2017 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 Audio Input demo. This file contains the main tasks of the demo and
+ * is responsible for the initial application hardware configuration.
+ */
+
+#include "AudioInput.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();
+ 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 | ADC_GET_CHANNEL_MASK(MIC_IN_ADC_CHANNEL));
+}
+
+/** 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
+}
+
+/** 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 sample reload timer */
+ TCCR0B = 0;
+
+ /* 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 data endpoint 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 written to and that the audio interface is enabled */
+ if (Endpoint_IsINReady() && StreamingAudioInterfaceSelected)
+ {
+ 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_Write_16_LE(AudioSample);
+
+ /* Check to see if the bank is now full */
+ if (!(Endpoint_IsReadWriteAllowed()))
+ {
+ /* Send the full packet to the host */
+ Endpoint_ClearIN();
+ }
+ }
+
+ Endpoint_SelectEndpoint(PrevEndpoint);
+}
+