Demos/Device/ClassDriver/AudioInput/AudioInput.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2011.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2011  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                                 .StreamingInterfaceNumber = 1,
  48
  49                                 .DataINEndpointNumber     = AUDIO_STREAM_EPNUM,
  50                                 .DataINEndpointSize       = AUDIO_STREAM_EPSIZE,
  51                         },
  52         };
  53
  54 /** Current audio sampling frequency of the streaming audio endpoint. */
  55 static uint32_t CurrentAudioSampleFrequency = 48000;
  56
  57
  58 /** Main program entry point. This routine contains the overall program flow, including initial
  59  *  setup of all components and the main program loop.
  60  */
  61 int main(void)
  62 {
  63         SetupHardware();
  64
  65         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
  66         sei();
  67
  68         for (;;)
  69         {
  70                 Audio_Device_USBTask(&Microphone_Audio_Interface);
  71                 USB_USBTask();
  72         }
  73 }
  74
  75 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  76 void SetupHardware(void)
  77 {
  78         /* Disable watchdog if enabled by bootloader/fuses */
  79         MCUSR &= ~(1 << WDRF);
  80         wdt_disable();
  81
  82         /* Disable clock division */
  83         clock_prescale_set(clock_div_1);
  84
  85         /* Hardware Initialization */
  86         LEDs_Init();
  87         Buttons_Init();
  88         ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
  89         ADC_SetupChannel(MIC_IN_ADC_CHANNEL);
  90         USB_Init();
  91
  92         /* Start the ADC conversion in free running mode */
  93         ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | MIC_IN_ADC_MUX_MASK);
  94 }
  95
  96 /** ISR to handle the reloading of the data endpoint with the next sample. */
  97 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
  98 {
  99         uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
 100
 101         /* Check that the USB bus is ready for the next sample to write */
 102         if (Audio_Device_IsReadyForNextSample(&Microphone_Audio_Interface))
 103         {
 104                 int16_t AudioSample;
 105
 106                 #if defined(USE_TEST_TONE)
 107                         static uint8_t SquareWaveSampleCount;
 108                         static int16_t CurrentWaveValue;
 109
 110                         /* In test tone mode, generate a square wave at 1/256 of the sample rate */
 111                         if (SquareWaveSampleCount++ == 0xFF)
 112                           CurrentWaveValue ^= 0x8000;
 113
 114                         /* Only generate audio if the board button is being pressed */
 115                         AudioSample = (Buttons_GetStatus() & BUTTONS_BUTTON1) ? CurrentWaveValue : 0;
 116                 #else
 117                         /* Audio sample is ADC value scaled to fit the entire range */
 118                         AudioSample = ((SAMPLE_MAX_RANGE / ADC_MAX_RANGE) * ADC_GetResult());
 119
 120                         #if defined(MICROPHONE_BIASED_TO_HALF_RAIL)
 121                         /* Microphone is biased to half rail voltage, subtract the bias from the sample value */
 122                         AudioSample -= (SAMPLE_MAX_RANGE / 2);
 123                         #endif
 124                 #endif
 125
 126                 Audio_Device_WriteSample16(&Microphone_Audio_Interface, AudioSample);
 127         }
 128
 129         Endpoint_SelectEndpoint(PrevEndpoint);
 130 }
 131
 132 /** Event handler for the library USB Connection event. */
 133 void EVENT_USB_Device_Connect(void)
 134 {
 135         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 136
 137         /* Sample reload timer initialization */
 138         TIMSK0  = (1 << OCIE0A);
 139         OCR0A   = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 140         TCCR0A  = (1 << WGM01);  // CTC mode
 141         TCCR0B  = (1 << CS01);   // Fcpu/8 speed
 142 }
 143
 144 /** Event handler for the library USB Disconnection event. */
 145 void EVENT_USB_Device_Disconnect(void)
 146 {
 147         /* Stop the sample reload timer */
 148         TCCR0B = 0;
 149
 150         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
 151 }
 152
 153 /** Event handler for the library USB Configuration Changed event. */
 154 void EVENT_USB_Device_ConfigurationChanged(void)
 155 {
 156         bool ConfigSuccess = true;
 157
 158         ConfigSuccess &= Audio_Device_ConfigureEndpoints(&Microphone_Audio_Interface);
 159
 160         LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 161 }
 162
 163 /** Event handler for the library USB Control Request reception event. */
 164 void EVENT_USB_Device_ControlRequest(void)
 165 {
 166         Audio_Device_ProcessControlRequest(&Microphone_Audio_Interface);
 167 }
 168
 169 /** Audio class driver callback for the setting and retrieval of streaming endpoint properties. This callback must be implemented
 170  *  in the user application to handle property manipulations on streaming audio endpoints.
 171  *
 172  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 173  *  the given endpoint index, and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 174  *  to indicate the size of the retreived data.
 175  *
 176  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 177  *        of the \c DataLength parameter.
 178  *
 179  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 180  *  \param[in]     EndpointProperty    Property of the endpoint to get or set, a value from Audio_ClassRequests_t.
 181  *  \param[in]     EndpointAddress     Address of the streaming endpoint whose property is being referenced.
 182  *  \param[in]     EndpointControl     Parameter of the endpoint to get or set, a value from Audio_EndpointControls_t.
 183  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 184  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 185  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 186  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 187  *                                     the retrieved data is to be stored for GET operations.
 188  *
 189  *  \return Boolean \c true if the property get/set was successful, \c false otherwise
 190  */
 191 bool CALLBACK_Audio_Device_GetSetEndpointProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 192                                                   const uint8_t EndpointProperty,
 193                                                   const uint8_t EndpointAddress,
 194                                                   const uint8_t EndpointControl,
 195                                                   uint16_t* const DataLength,
 196                                                   uint8_t* Data)
 197 {
 198         /* Check the requested endpoint to see if a supported endpoint is being manipulated */
 199         if (EndpointAddress == (ENDPOINT_DIR_IN | Microphone_Audio_Interface.Config.DataINEndpointNumber))
 200         {
 201                 /* Check the requested control to see if a supported control is being manipulated */
 202                 if (EndpointControl == AUDIO_EPCONTROL_SamplingFreq)
 203                 {
 204                         switch (EndpointProperty)
 205                         {
 206                                 case AUDIO_REQ_SetCurrent:
 207                                         /* Check if we are just testing for a valid property, or actually adjusting it */
 208                                         if (DataLength != NULL)
 209                                         {
 210                                                 /* Set the new sampling frequency to the value given by the host */
 211                                                 CurrentAudioSampleFrequency = (((uint32_t)Data[2] << 16) | ((uint32_t)Data[1] << 8) | (uint32_t)Data[0]);
 212
 213                                                 /* Adjust sample reload timer to the new frequency */
 214                                                 OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 215                                         }
 216
 217                                         return true;
 218                                 case AUDIO_REQ_GetCurrent:
 219                                         /* Check if we are just testing for a valid property, or actually reading it */
 220                                         if (DataLength != NULL)
 221                                         {
 222                                                 *DataLength = 3;
 223
 224                                                 Data[2] = (CurrentAudioSampleFrequency >> 16);
 225                                                 Data[1] = (CurrentAudioSampleFrequency >> 8);
 226                                                 Data[0] = (CurrentAudioSampleFrequency &  0xFF);
 227                                         }
 228
 229                                         return true;
 230                         }
 231                 }
 232         }
 233
 234         return false;
 235 }
 236
 237 /** Audio class driver callback for the setting and retrieval of streaming interface properties. This callback must be implemented
 238  *  in the user application to handle property manipulations on streaming audio interfaces.
 239  *
 240  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 241  *  the given entity and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 242  *  to indicate the size of the retreived data.
 243  *
 244  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 245  *        of the \c DataLength parameter.
 246  *
 247  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 248  *  \param[in]     Property            Property of the interface to get or set, a value from \ref Audio_ClassRequests_t.
 249  *  \param[in]     EntityAddress       Address of the audio entity whose property is being referenced.
 250  *  \param[in]     Parameter           Parameter of the entity to get or set, specific to each type of entity (see USB Audio specification).
 251  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 252  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 253  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 254  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 255  *                                     the retrieved data is to be stored for GET operations.
 256  *
 257  *  \return Boolean \c true if the property GET/SET was successful, \c false otherwise
 258  */
 259 bool CALLBACK_Audio_Device_GetSetInterfaceProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 260                                                    const uint8_t Property,
 261                                                    const uint8_t EntityAddress,
 262                                                    const uint16_t Parameter,
 263                                                    uint16_t* const DataLength,
 264                                                    uint8_t* Data)
 265 {
 266         /* No audio interface entities in the device descriptor, thus no properties to get or set. */
 267         return false;
 268 }