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
  50                                 .DataINEndpointNumber     = AUDIO_STREAM_EPNUM,
  51                                 .DataINEndpointSize       = AUDIO_STREAM_EPSIZE,
  52                         },
  53         };
  54
  55 /** Current audio sampling frequency of the streaming audio endpoint. */
  56 static uint32_t CurrentAudioSampleFrequency = 48000;
  57
  58
  59 /** Main program entry point. This routine contains the overall program flow, including initial
  60  *  setup of all components and the main program loop.
  61  */
  62 int main(void)
  63 {
  64         SetupHardware();
  65
  66         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
  67         sei();
  68
  69         for (;;)
  70         {
  71                 Audio_Device_USBTask(&Microphone_Audio_Interface);
  72                 USB_USBTask();
  73         }
  74 }
  75
  76 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  77 void SetupHardware(void)
  78 {
  79         /* Disable watchdog if enabled by bootloader/fuses */
  80         MCUSR &= ~(1 << WDRF);
  81         wdt_disable();
  82
  83         /* Disable clock division */
  84         clock_prescale_set(clock_div_1);
  85
  86         /* Hardware Initialization */
  87         LEDs_Init();
  88         Buttons_Init();
  89         ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_32);
  90         ADC_SetupChannel(MIC_IN_ADC_CHANNEL);
  91         USB_Init();
  92
  93         /* Start the ADC conversion in free running mode */
  94         ADC_StartReading(ADC_REFERENCE_AVCC | ADC_RIGHT_ADJUSTED | MIC_IN_ADC_MUX_MASK);
  95 }
  96
  97 /** ISR to handle the reloading of the data endpoint with the next sample. */
  98 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
  99 {
 100         uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
 101
 102         /* Check that the USB bus is ready for the next sample to write */
 103         if (Audio_Device_IsReadyForNextSample(&Microphone_Audio_Interface))
 104         {
 105                 int16_t AudioSample;
 106
 107                 #if defined(USE_TEST_TONE)
 108                         static uint8_t SquareWaveSampleCount;
 109                         static int16_t CurrentWaveValue;
 110
 111                         /* In test tone mode, generate a square wave at 1/256 of the sample rate */
 112                         if (SquareWaveSampleCount++ == 0xFF)
 113                           CurrentWaveValue ^= 0x8000;
 114
 115                         /* Only generate audio if the board button is being pressed */
 116                         AudioSample = (Buttons_GetStatus() & BUTTONS_BUTTON1) ? CurrentWaveValue : 0;
 117                 #else
 118                         /* Audio sample is ADC value scaled to fit the entire range */
 119                         AudioSample = ((SAMPLE_MAX_RANGE / ADC_MAX_RANGE) * ADC_GetResult());
 120
 121                         #if defined(MICROPHONE_BIASED_TO_HALF_RAIL)
 122                         /* Microphone is biased to half rail voltage, subtract the bias from the sample value */
 123                         AudioSample -= (SAMPLE_MAX_RANGE / 2);
 124                         #endif
 125                 #endif
 126
 127                 Audio_Device_WriteSample16(&Microphone_Audio_Interface, AudioSample);
 128         }
 129
 130         Endpoint_SelectEndpoint(PrevEndpoint);
 131 }
 132
 133 /** Event handler for the library USB Connection event. */
 134 void EVENT_USB_Device_Connect(void)
 135 {
 136         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 137
 138         /* Sample reload timer initialization */
 139         TIMSK0  = (1 << OCIE0A);
 140         OCR0A   = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 141         TCCR0A  = (1 << WGM01);  // CTC mode
 142         TCCR0B  = (1 << CS01);   // Fcpu/8 speed
 143 }
 144
 145 /** Event handler for the library USB Disconnection event. */
 146 void EVENT_USB_Device_Disconnect(void)
 147 {
 148         /* Stop the sample reload timer */
 149         TCCR0B = 0;
 150
 151         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
 152 }
 153
 154 /** Event handler for the library USB Configuration Changed event. */
 155 void EVENT_USB_Device_ConfigurationChanged(void)
 156 {
 157         bool ConfigSuccess = true;
 158
 159         ConfigSuccess &= Audio_Device_ConfigureEndpoints(&Microphone_Audio_Interface);
 160
 161         LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 162 }
 163
 164 /** Event handler for the library USB Control Request reception event. */
 165 void EVENT_USB_Device_ControlRequest(void)
 166 {
 167         Audio_Device_ProcessControlRequest(&Microphone_Audio_Interface);
 168 }
 169
 170 /** Audio class driver callback for the setting and retrieval of streaming endpoint properties. This callback must be implemented
 171  *  in the user application to handle property manipulations on streaming audio endpoints.
 172  *
 173  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 174  *  the given endpoint index, and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 175  *  to indicate the size of the retreived data.
 176  *
 177  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 178  *        of the \c DataLength parameter.
 179  *
 180  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 181  *  \param[in]     EndpointProperty    Property of the endpoint to get or set, a value from Audio_ClassRequests_t.
 182  *  \param[in]     EndpointAddress     Address of the streaming endpoint whose property is being referenced.
 183  *  \param[in]     EndpointControl     Parameter of the endpoint to get or set, a value from Audio_EndpointControls_t.
 184  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 185  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 186  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 187  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 188  *                                     the retrieved data is to be stored for GET operations.
 189  *
 190  *  \return Boolean \c true if the property get/set was successful, \c false otherwise
 191  */
 192 bool CALLBACK_Audio_Device_GetSetEndpointProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 193                                                   const uint8_t EndpointProperty,
 194                                                   const uint8_t EndpointAddress,
 195                                                   const uint8_t EndpointControl,
 196                                                   uint16_t* const DataLength,
 197                                                   uint8_t* Data)
 198 {
 199         /* Check the requested endpoint to see if a supported endpoint is being manipulated */
 200         if (EndpointAddress == (ENDPOINT_DIR_IN | Microphone_Audio_Interface.Config.DataINEndpointNumber))
 201         {
 202                 /* Check the requested control to see if a supported control is being manipulated */
 203                 if (EndpointControl == AUDIO_EPCONTROL_SamplingFreq)
 204                 {
 205                         switch (EndpointProperty)
 206                         {
 207                                 case AUDIO_REQ_SetCurrent:
 208                                         /* Check if we are just testing for a valid property, or actually adjusting it */
 209                                         if (DataLength != NULL)
 210                                         {
 211                                                 /* Set the new sampling frequency to the value given by the host */
 212                                                 CurrentAudioSampleFrequency = (((uint32_t)Data[2] << 16) | ((uint32_t)Data[1] << 8) | (uint32_t)Data[0]);
 213
 214                                                 /* Adjust sample reload timer to the new frequency */
 215                                                 OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 216                                         }
 217
 218                                         return true;
 219                                 case AUDIO_REQ_GetCurrent:
 220                                         /* Check if we are just testing for a valid property, or actually reading it */
 221                                         if (DataLength != NULL)
 222                                         {
 223                                                 *DataLength = 3;
 224
 225                                                 Data[2] = (CurrentAudioSampleFrequency >> 16);
 226                                                 Data[1] = (CurrentAudioSampleFrequency >> 8);
 227                                                 Data[0] = (CurrentAudioSampleFrequency &  0xFF);
 228                                         }
 229
 230                                         return true;
 231                         }
 232                 }
 233         }
 234
 235         return false;
 236 }
 237
 238 /** Audio class driver callback for the setting and retrieval of streaming interface properties. This callback must be implemented
 239  *  in the user application to handle property manipulations on streaming audio interfaces.
 240  *
 241  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 242  *  the given entity and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 243  *  to indicate the size of the retreived data.
 244  *
 245  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 246  *        of the \c DataLength parameter.
 247  *
 248  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 249  *  \param[in]     Property            Property of the interface to get or set, a value from Audio_ClassRequests_t.
 250  *  \param[in]     EntityAddress       Address of the audio entity whose property is being referenced.
 251  *  \param[in]     Parameter           Parameter of the entity to get or set, specific to each type of entity (see USB Audio specification).
 252  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 253  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 254  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 255  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 256  *                                     the retrieved data is to be stored for GET operations.
 257  *
 258  *  \return Boolean \c true if the property GET/SET was successful, \c false otherwise
 259  */
 260 bool CALLBACK_Audio_Device_GetSetInterfaceProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 261                                                    const uint8_t Property,
 262                                                    const uint8_t EntityAddress,
 263                                                    const uint16_t Parameter,
 264                                                    uint16_t* const DataLength,
 265                                                    uint8_t* Data)
 266 {
 267         /* No audio interface entities in the device descriptor, thus no properties to get or set. */
 268         return false;
 269 }