X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/071e02c6b6b4837fa9cf0b6d4c749994e02638d7..a8b66f318dda3cc18dfcedaa3af3d01ab68b82e8:/Demos/Device/LowLevel/AudioInput/AudioInput.c?ds=sidebyside diff --git a/Demos/Device/LowLevel/AudioInput/AudioInput.c b/Demos/Device/LowLevel/AudioInput/AudioInput.c index 6655a27ee..16ac90e8f 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. - + 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 @@ -48,10 +48,9 @@ int main(void) LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY); sei(); - + for (;;) { - USB_Audio_Task(); USB_USBTask(); } } @@ -65,13 +64,14 @@ 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 +85,8 @@ 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 / AUDIO_SAMPLE_FREQUENCY) - 1); TCCR0A = (1 << WGM01); // CTC mode TCCR0B = (1 << CS01); // Fcpu/8 speed } @@ -110,23 +111,21 @@ void EVENT_USB_Device_Disconnect(void) */ void EVENT_USB_Device_ConfigurationChanged(void) { - /* Indicate USB connected and ready */ - LEDs_SetAllLEDs(LEDMASK_USB_READY); + bool ConfigSuccess = true; - /* Setup audio stream endpoint */ - if (!(Endpoint_ConfigureEndpoint(AUDIO_STREAM_EPNUM, EP_TYPE_ISOCHRONOUS, - ENDPOINT_DIR_IN, AUDIO_STREAM_EPSIZE, - ENDPOINT_BANK_DOUBLE))) - { - LEDs_SetAllLEDs(LEDMASK_USB_ERROR); - } + /* Setup Audio Stream Endpoint */ + ConfigSuccess &= Endpoint_ConfigureEndpoint(AUDIO_STREAM_EPNUM, EP_TYPE_ISOCHRONOUS, ENDPOINT_DIR_IN, + AUDIO_STREAM_EPSIZE, ENDPOINT_BANK_DOUBLE); + + /* Indicate endpoint configuration success or failure */ + 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) @@ -136,43 +135,47 @@ 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); - - Endpoint_ClearStatusStage(); } 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 */ @@ -185,4 +188,7 @@ void USB_Audio_Task(void) Endpoint_ClearIN(); } } + + Endpoint_SelectEndpoint(PrevEndpoint); } +