X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/508e905d8d39c3968927aa2c1a45350f49452df1..77a9df36a77d2523dd2bc24fa17f9f04c6c175c5:/Demos/Device/LowLevel/AudioInput/AudioInput.c diff --git a/Demos/Device/LowLevel/AudioInput/AudioInput.c b/Demos/Device/LowLevel/AudioInput/AudioInput.c index eb29f34f7..e00b693f9 100644 --- a/Demos/Device/LowLevel/AudioInput/AudioInput.c +++ b/Demos/Device/LowLevel/AudioInput/AudioInput.c @@ -1,21 +1,21 @@ /* LUFA Library - Copyright (C) Dean Camera, 2010. - + Copyright (C) Dean Camera, 2011. + dean [at] fourwalledcubicle [dot] com - www.fourwalledcubicle.com + www.lufa-lib.org */ /* - Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com) + Copyright 2011 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 @@ -37,7 +37,11 @@ #include "AudioInput.h" /** Flag to indicate if the streaming audio alternative interface has been selected by the host. */ -bool StreamingAudioInterfaceSelected = false; +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. @@ -48,10 +52,9 @@ int main(void) LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY); sei(); - + for (;;) { - USB_Audio_Task(); USB_USBTask(); } } @@ -65,13 +68,14 @@ void SetupHardware(void) /* 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); } @@ -85,7 +89,8 @@ void EVENT_USB_Device_Connect(void) LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING); /* Sample reload timer initialization */ - OCR0A = (F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1; + TIMSK0 = (1 << OCIE0A); + OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1); TCCR0A = (1 << WGM01); // CTC mode TCCR0B = (1 << CS01); // Fcpu/8 speed } @@ -120,11 +125,11 @@ void EVENT_USB_Device_ConfigurationChanged(void) 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) @@ -134,47 +139,111 @@ void EVENT_USB_Device_UnhandledControlRequest(void) 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 == (ENDPOINT_DESCRIPTOR_DIR_IN | AUDIO_STREAM_EPNUM)) && (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 == (ENDPOINT_DESCRIPTOR_DIR_IN | AUDIO_STREAM_EPNUM)) && (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; } } -/** 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_Write_Word_LE(AudioSample); + Endpoint_Write_16_LE(AudioSample); /* Check to see if the bank is now full */ if (!(Endpoint_IsReadWriteAllowed())) @@ -183,4 +252,7 @@ void USB_Audio_Task(void) Endpoint_ClearIN(); } } + + Endpoint_SelectEndpoint(PrevEndpoint); } +