Demos/Device/ClassDriver/AudioInput/AudioInput.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2012.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2012  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  Main source file for the AudioInput demo. This file contains the main tasks of
  34  *  the demo and is responsible for the initial application hardware configuration.
  35  */
  36
  37 #include "AudioInput.h"
  38
  39 /** LUFA Audio Class driver interface configuration and state information. This structure is
  40  *  passed to all Audio Class driver functions, so that multiple instances of the same class
  41  *  within a device can be differentiated from one another.
  42  */
  43 USB_ClassInfo_Audio_Device_t Microphone_Audio_Interface =
  44         {
  45                 .Config =
  46                         {
  47                                 .ControlInterfaceNumber   = 0,
  48                                 .StreamingInterfaceNumber = 1,
  49                                 .DataINEndpoint           =
  50                                         {
  51                                                 .Address          = AUDIO_STREAM_EPADDR,
  52                                                 .Size             = AUDIO_STREAM_EPSIZE,
  53                                                 .Banks            = 2,
  54                                         },
  55                         },
  56         };
  57
  58 /** Current audio sampling frequency of the streaming audio endpoint. */
  59 static uint32_t CurrentAudioSampleFrequency = 48000;
  60
  61
  62 /** Main program entry point. This routine contains the overall program flow, including initial
  63  *  setup of all components and the main program loop.
  64  */
  65 int main(void)
  66 {
  67         SetupHardware();
  68
  69         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
  70         sei();
  71
  72         for (;;)
  73         {
  74                 Audio_Device_USBTask(&Microphone_Audio_Interface);
  75                 USB_USBTask();
  76         }
  77 }
  78
  79 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  80 void SetupHardware(void)
  81 {
  82         /* Disable watchdog if enabled by bootloader/fuses */
  83         MCUSR &= ~(1 << WDRF);
  84         wdt_disable();
  85
  86         /* Disable clock division */
  87         clock_prescale_set(clock_div_1);
  88
  89         /* Hardware Initialization */
  90         LEDs_Init();
  91         Buttons_Init();
  92         ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
  93         ADC_SetupChannel(MIC_IN_ADC_CHANNEL);
  94         USB_Init();
  95
  96         /* Start the ADC conversion in free running mode */
  97         ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | ADC_GET_CHANNEL_MASK(MIC_IN_ADC_CHANNEL));
  98 }
  99
 100 /** ISR to handle the reloading of the data endpoint with the next sample. */
 101 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 102 {
 103         uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
 104
 105         /* Check that the USB bus is ready for the next sample to write */
 106         if (Audio_Device_IsReadyForNextSample(&Microphone_Audio_Interface))
 107         {
 108                 int16_t AudioSample;
 109
 110                 #if defined(USE_TEST_TONE)
 111                         static uint8_t SquareWaveSampleCount;
 112                         static int16_t CurrentWaveValue;
 113
 114                         /* In test tone mode, generate a square wave at 1/256 of the sample rate */
 115                         if (SquareWaveSampleCount++ == 0xFF)
 116                           CurrentWaveValue ^= 0x8000;
 117
 118                         /* Only generate audio if the board button is being pressed */
 119                         AudioSample = (Buttons_GetStatus() & BUTTONS_BUTTON1) ? CurrentWaveValue : 0;
 120                 #else
 121                         /* Audio sample is ADC value scaled to fit the entire range */
 122                         AudioSample = ((SAMPLE_MAX_RANGE / ADC_MAX_RANGE) * ADC_GetResult());
 123
 124                         #if defined(MICROPHONE_BIASED_TO_HALF_RAIL)
 125                         /* Microphone is biased to half rail voltage, subtract the bias from the sample value */
 126                         AudioSample -= (SAMPLE_MAX_RANGE / 2);
 127                         #endif
 128                 #endif
 129
 130                 Audio_Device_WriteSample16(&Microphone_Audio_Interface, AudioSample);
 131         }
 132
 133         Endpoint_SelectEndpoint(PrevEndpoint);
 134 }
 135
 136 /** Event handler for the library USB Connection event. */
 137 void EVENT_USB_Device_Connect(void)
 138 {
 139         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 140
 141         /* Sample reload timer initialization */
 142         TIMSK0  = (1 << OCIE0A);
 143         OCR0A   = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 144         TCCR0A  = (1 << WGM01);  // CTC mode
 145         TCCR0B  = (1 << CS01);   // Fcpu/8 speed
 146 }
 147
 148 /** Event handler for the library USB Disconnection event. */
 149 void EVENT_USB_Device_Disconnect(void)
 150 {
 151         /* Stop the sample reload timer */
 152         TCCR0B = 0;
 153
 154         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
 155 }
 156
 157 /** Event handler for the library USB Configuration Changed event. */
 158 void EVENT_USB_Device_ConfigurationChanged(void)
 159 {
 160         bool ConfigSuccess = true;
 161
 162         ConfigSuccess &= Audio_Device_ConfigureEndpoints(&Microphone_Audio_Interface);
 163
 164         LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 165 }
 166
 167 /** Event handler for the library USB Control Request reception event. */
 168 void EVENT_USB_Device_ControlRequest(void)
 169 {
 170         Audio_Device_ProcessControlRequest(&Microphone_Audio_Interface);
 171 }
 172
 173 /** Audio class driver callback for the setting and retrieval of streaming endpoint properties. This callback must be implemented
 174  *  in the user application to handle property manipulations on streaming audio endpoints.
 175  *
 176  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 177  *  the given endpoint index, and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 178  *  to indicate the size of the retrieved data.
 179  *
 180  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 181  *        of the \c DataLength parameter.
 182  *
 183  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 184  *  \param[in]     EndpointProperty    Property of the endpoint to get or set, a value from Audio_ClassRequests_t.
 185  *  \param[in]     EndpointAddress     Address of the streaming endpoint whose property is being referenced.
 186  *  \param[in]     EndpointControl     Parameter of the endpoint to get or set, a value from Audio_EndpointControls_t.
 187  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 188  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 189  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 190  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 191  *                                     the retrieved data is to be stored for GET operations.
 192  *
 193  *  \return Boolean \c true if the property get/set was successful, \c false otherwise
 194  */
 195 bool CALLBACK_Audio_Device_GetSetEndpointProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 196                                                   const uint8_t EndpointProperty,
 197                                                   const uint8_t EndpointAddress,
 198                                                   const uint8_t EndpointControl,
 199                                                   uint16_t* const DataLength,
 200                                                   uint8_t* Data)
 201 {
 202         /* Check the requested endpoint to see if a supported endpoint is being manipulated */
 203         if (EndpointAddress == Microphone_Audio_Interface.Config.DataINEndpoint.Address)
 204         {
 205                 /* Check the requested control to see if a supported control is being manipulated */
 206                 if (EndpointControl == AUDIO_EPCONTROL_SamplingFreq)
 207                 {
 208                         switch (EndpointProperty)
 209                         {
 210                                 case AUDIO_REQ_SetCurrent:
 211                                         /* Check if we are just testing for a valid property, or actually adjusting it */
 212                                         if (DataLength != NULL)
 213                                         {
 214                                                 /* Set the new sampling frequency to the value given by the host */
 215                                                 CurrentAudioSampleFrequency = (((uint32_t)Data[2] << 16) | ((uint32_t)Data[1] << 8) | (uint32_t)Data[0]);
 216
 217                                                 /* Adjust sample reload timer to the new frequency */
 218                                                 OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 219                                         }
 220
 221                                         return true;
 222                                 case AUDIO_REQ_GetCurrent:
 223                                         /* Check if we are just testing for a valid property, or actually reading it */
 224                                         if (DataLength != NULL)
 225                                         {
 226                                                 *DataLength = 3;
 227
 228                                                 Data[2] = (CurrentAudioSampleFrequency >> 16);
 229                                                 Data[1] = (CurrentAudioSampleFrequency >> 8);
 230                                                 Data[0] = (CurrentAudioSampleFrequency &  0xFF);
 231                                         }
 232
 233                                         return true;
 234                         }
 235                 }
 236         }
 237
 238         return false;
 239 }
 240
 241 /** Audio class driver callback for the setting and retrieval of streaming interface properties. This callback must be implemented
 242  *  in the user application to handle property manipulations on streaming audio interfaces.
 243  *
 244  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 245  *  the given entity and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 246  *  to indicate the size of the retrieved data.
 247  *
 248  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 249  *        of the \c DataLength parameter.
 250  *
 251  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 252  *  \param[in]     Property            Property of the interface to get or set, a value from Audio_ClassRequests_t.
 253  *  \param[in]     EntityAddress       Address of the audio entity whose property is being referenced.
 254  *  \param[in]     Parameter           Parameter of the entity to get or set, specific to each type of entity (see USB Audio specification).
 255  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 256  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 257  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 258  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 259  *                                     the retrieved data is to be stored for GET operations.
 260  *
 261  *  \return Boolean \c true if the property GET/SET was successful, \c false otherwise
 262  */
 263 bool CALLBACK_Audio_Device_GetSetInterfaceProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 264                                                    const uint8_t Property,
 265                                                    const uint8_t EntityAddress,
 266                                                    const uint16_t Parameter,
 267                                                    uint16_t* const DataLength,
 268                                                    uint8_t* Data)
 269 {
 270         /* No audio interface entities in the device descriptor, thus no properties to get or set. */
 271         return false;
 272 }