X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/071e02c6b6b4837fa9cf0b6d4c749994e02638d7..d4b45e8502a27c0f5ad3e26eabd2b30e84c20bac:/Demos/Device/LowLevel/AudioOutput/AudioOutput.c diff --git a/Demos/Device/LowLevel/AudioOutput/AudioOutput.c b/Demos/Device/LowLevel/AudioOutput/AudioOutput.c index db6bc3c75..813108a71 100644 --- a/Demos/Device/LowLevel/AudioOutput/AudioOutput.c +++ b/Demos/Device/LowLevel/AudioOutput/AudioOutput.c @@ -1,21 +1,21 @@ /* LUFA Library - Copyright (C) Dean Camera, 2010. - + Copyright (C) Dean Camera, 2012. + dean [at] fourwalledcubicle [dot] com - www.fourwalledcubicle.com + www.lufa-lib.org */ /* - Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com) + Copyright 2012 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 @@ -33,11 +33,15 @@ * Main source file for the AudioOutput demo. This file contains the main tasks of the demo and * is responsible for the initial application hardware configuration. */ - + #include "AudioOutput.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(); } } @@ -65,7 +68,7 @@ void SetupHardware(void) /* Disable clock division */ clock_prescale_set(clock_div_1); - + /* Hardware Initialization */ LEDs_Init(); USB_Init(); @@ -78,29 +81,30 @@ void EVENT_USB_Device_Connect(void) { /* Indicate USB enumerating */ LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING); - + /* Sample reload timer initialization */ - OCR0A = (F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1; - TCCR0A = (1 << WGM01); // CTC mode - TCCR0B = (1 << CS01); // Fcpu/8 speed - -#if defined(AUDIO_OUT_MONO) + TIMSK0 = (1 << OCIE0A); + OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1); + TCCR0A = (1 << WGM01); // CTC mode + TCCR0B = (1 << CS01); // Fcpu/8 speed + + #if defined(AUDIO_OUT_MONO) /* Set speaker as output */ - DDRC |= (1 << 6); -#elif defined(AUDIO_OUT_STEREO) + DDRC |= (1 << 6); + #elif defined(AUDIO_OUT_STEREO) /* Set speakers as outputs */ - DDRC |= ((1 << 6) | (1 << 5)); -#elif defined(AUDIO_OUT_PORTC) + DDRC |= ((1 << 6) | (1 << 5)); + #elif defined(AUDIO_OUT_PORTC) /* Set PORTC as outputs */ - DDRC |= 0xFF; -#endif + DDRC |= 0xFF; + #endif -#if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO)) + #if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO)) /* PWM speaker timer initialization */ - TCCR3A = ((1 << WGM30) | (1 << COM3A1) | (1 << COM3A0) - | (1 << COM3B1) | (1 << COM3B0)); // Set on match, clear on TOP - TCCR3B = ((1 << WGM32) | (1 << CS30)); // Fast 8-Bit PWM, Fcpu speed -#endif + TCCR3A = ((1 << WGM30) | (1 << COM3A1) | (1 << COM3A0) + | (1 << COM3B1) | (1 << COM3B0)); // Set on match, clear on TOP + TCCR3B = ((1 << WGM32) | (1 << CS30)); // Fast 8-Bit PWM, F_CPU speed + #endif } /** Event handler for the USB_Disconnect event. This indicates that the device is no longer connected to a host via @@ -110,20 +114,20 @@ void EVENT_USB_Device_Disconnect(void) { /* Stop the timers */ TCCR0B = 0; -#if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO)) + #if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO)) TCCR3B = 0; -#endif + #endif -#if defined(AUDIO_OUT_MONO) + #if defined(AUDIO_OUT_MONO) /* Set speaker as input to reduce current draw */ - DDRC &= ~(1 << 6); -#elif defined(AUDIO_OUT_STEREO) + DDRC &= ~(1 << 6); + #elif defined(AUDIO_OUT_STEREO) /* Set speakers as inputs to reduce current draw */ - DDRC &= ~((1 << 6) | (1 << 5)); -#elif defined(AUDIO_OUT_PORTC) + DDRC &= ~((1 << 6) | (1 << 5)); + #elif defined(AUDIO_OUT_PORTC) /* Set PORTC low */ - PORTC = 0x00; -#endif + PORTC = 0x00; + #endif /* Indicate streaming audio interface not selected */ StreamingAudioInterfaceSelected = false; @@ -137,23 +141,21 @@ 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_OUT, 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_OUT, + 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) @@ -163,45 +165,93 @@ 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_DIR_OUT | AUDIO_STREAM_EPNUM)) && (EndpointControl == AUDIO_EPCONTROL_SamplingFreq)) + { + uint8_t SampleRate[3]; + + Endpoint_ClearSETUP(); + Endpoint_Read_Control_Stream_LE(SampleRate, sizeof(SampleRate)); + Endpoint_ClearOUT(); + + /* 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_HOSTTODEVICE | 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_DIR_OUT | 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 audio samples from the host, and outputting them to the speakers/LEDs as - * desired. - */ -void USB_Audio_Task(void) +/** ISR to handle the reloading of the PWM timer 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 read from (contains a packet) and that the next sample should be read */ - if (Endpoint_IsOUTReceived() && (TIFR0 & (1 << OCF0A))) - { - /* Clear the sample reload timer */ - TIFR0 |= (1 << OCF0A); + /* Check if the current endpoint can be read from (contains a packet) and the host is sending data */ + if (Endpoint_IsOUTReceived() && StreamingAudioInterfaceSelected) + { /* Retrieve the signed 16-bit left and right audio samples, convert to 8-bit */ - int8_t LeftSample_8Bit = ((int16_t)Endpoint_Read_Word_LE() >> 8); - int8_t RightSample_8Bit = ((int16_t)Endpoint_Read_Word_LE() >> 8); + int8_t LeftSample_8Bit = ((int16_t)Endpoint_Read_16_LE() >> 8); + int8_t RightSample_8Bit = ((int16_t)Endpoint_Read_16_LE() >> 8); /* Mix the two channels together to produce a mono, 8-bit sample */ - int8_t MixedSample_8Bit = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1); + int8_t MixedSample_8Bit = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1); /* Check to see if the bank is now empty */ if (!(Endpoint_IsReadWriteAllowed())) @@ -210,17 +260,17 @@ void USB_Audio_Task(void) Endpoint_ClearOUT(); } -#if defined(AUDIO_OUT_MONO) + #if defined(AUDIO_OUT_MONO) /* Load the sample into the PWM timer channel */ OCR3A = (MixedSample_8Bit ^ (1 << 7)); -#elif defined(AUDIO_OUT_STEREO) + #elif defined(AUDIO_OUT_STEREO) /* Load the dual 8-bit samples into the PWM timer channels */ OCR3A = (LeftSample_8Bit ^ (1 << 7)); OCR3B = (RightSample_8Bit ^ (1 << 7)); -#elif defined(AUDIO_OUT_PORTC) + #elif defined(AUDIO_OUT_PORTC) /* Load the 8-bit mixed sample into PORTC */ PORTC = MixedSample_8Bit; -#endif + #endif uint8_t LEDMask = LEDS_NO_LEDS; @@ -236,4 +286,7 @@ void USB_Audio_Task(void) LEDs_SetAllLEDs(LEDMask); } + + Endpoint_SelectEndpoint(PrevEndpoint); } +