3      Copyright (C) Dean Camera, 2012. 
   5   dean [at] fourwalledcubicle [dot] com 
  10   Copyright 2012  Dean Camera (dean [at] fourwalledcubicle [dot] com) 
  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. 
  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 
  33  *  Main source file for the AudioOutputHost demo. This file contains the main tasks of 
  34  *  the demo and is responsible for the initial application hardware configuration. 
  37 #include "AudioOutputHost.h" 
  39 /** Main program entry point. This routine configures the hardware required by the application, then 
  40  *  enters a loop to run the application tasks in sequence. 
  46         puts_P(PSTR(ESC_FG_CYAN 
"Audio Output Host Demo running.\r\n" ESC_FG_WHITE
)); 
  48         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY
); 
  57 /** Configures the board hardware and chip peripherals for the demo's functionality. */ 
  58 void SetupHardware(void) 
  60         /* Disable watchdog if enabled by bootloader/fuses */ 
  61         MCUSR 
&= ~(1 << WDRF
); 
  64         /* Disable clock division */ 
  65         clock_prescale_set(clock_div_1
); 
  67         /* Hardware Initialization */ 
  68         Serial_Init(9600, false); 
  70         ADC_Init(ADC_FREE_RUNNING 
| ADC_PRESCALE_32
); 
  71         ADC_SetupChannel(MIC_IN_ADC_CHANNEL
); 
  75         /* Create a stdio stream for the serial port for stdin and stdout */ 
  76         Serial_CreateStream(NULL
); 
  78         /* Start the ADC conversion in free running mode */ 
  79         ADC_StartReading(ADC_REFERENCE_AVCC 
| ADC_RIGHT_ADJUSTED 
| ADC_GET_CHANNEL_MASK(MIC_IN_ADC_CHANNEL
));    
  82 /** Event handler for the USB_DeviceAttached event. This indicates that a device has been attached to the host, and 
  83  *  starts the library USB task to begin the enumeration and USB management process. 
  85 void EVENT_USB_Host_DeviceAttached(void) 
  87         puts_P(PSTR(ESC_FG_GREEN 
"Device Attached.\r\n" ESC_FG_WHITE
)); 
  88         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING
); 
  91 /** Event handler for the USB_DeviceUnattached event. This indicates that a device has been removed from the host, and 
  92  *  stops the library USB task management process. 
  94 void EVENT_USB_Host_DeviceUnattached(void) 
  96         puts_P(PSTR(ESC_FG_GREEN 
"Device Unattached.\r\n" ESC_FG_WHITE
)); 
  97         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY
); 
 100 /** Event handler for the USB_DeviceEnumerationComplete event. This indicates that a device has been successfully 
 101  *  enumerated by the host and is now ready to be used by the application. 
 103 void EVENT_USB_Host_DeviceEnumerationComplete(void) 
 105         puts_P(PSTR("Getting Config Data.\r\n")); 
 109         /* Get and process the configuration descriptor data */ 
 110         if ((ErrorCode 
= ProcessConfigurationDescriptor()) != SuccessfulConfigRead
) 
 112                 if (ErrorCode 
== ControlError
) 
 113                   puts_P(PSTR(ESC_FG_RED 
"Control Error (Get Configuration).\r\n")); 
 115                   puts_P(PSTR(ESC_FG_RED 
"Invalid Device.\r\n")); 
 117                 printf_P(PSTR(" -- Error Code: %d\r\n" ESC_FG_WHITE
), ErrorCode
); 
 119                 LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 123         /* Set the device configuration to the first configuration (rarely do devices use multiple configurations) */ 
 124         if ((ErrorCode 
= USB_Host_SetDeviceConfiguration(1)) != HOST_SENDCONTROL_Successful
) 
 126                 printf_P(PSTR(ESC_FG_RED 
"Control Error (Set Configuration).\r\n" 
 127                                          " -- Error Code: %d\r\n" ESC_FG_WHITE
), ErrorCode
); 
 129                 LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 133         if ((ErrorCode 
= USB_Host_SetInterfaceAltSetting(StreamingInterfaceIndex
, 
 134                                                          StreamingInterfaceAltSetting
)) != HOST_SENDCONTROL_Successful
) 
 136                 printf_P(PSTR(ESC_FG_RED 
"Could not set alternative streaming interface setting.\r\n" 
 137                                          " -- Error Code: %d\r\n" ESC_FG_WHITE
), ErrorCode
); 
 139                 LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 140                 USB_Host_SetDeviceConfiguration(0); 
 144         USB_ControlRequest 
= (USB_Request_Header_t
) 
 146                         .bmRequestType 
= (REQDIR_HOSTTODEVICE 
| REQTYPE_CLASS 
| REQREC_ENDPOINT
), 
 147                         .bRequest      
= AUDIO_REQ_SetCurrent
, 
 148                         .wValue        
= (AUDIO_EPCONTROL_SamplingFreq 
<< 8), 
 149                         .wIndex        
= StreamingEndpointAddress
, 
 150                         .wLength       
= sizeof(USB_Audio_SampleFreq_t
), 
 153         USB_Audio_SampleFreq_t SampleRate 
= AUDIO_SAMPLE_FREQ(48000); 
 155         /* Select the control pipe for the request transfer */ 
 156         Pipe_SelectPipe(PIPE_CONTROLPIPE
); 
 158         /* Set the sample rate on the streaming interface endpoint */ 
 159         if ((ErrorCode 
= USB_Host_SendControlRequest(&SampleRate
)) != HOST_SENDCONTROL_Successful
) 
 161                 LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 162                 USB_Host_SetDeviceConfiguration(0); 
 166         /* Sample reload timer initialization */ 
 167         TIMSK0  
= (1 << OCIE0A
); 
 168         OCR0A   
= ((F_CPU 
/ 8 / 48000) - 1); 
 169         TCCR0A  
= (1 << WGM01
);  // CTC mode 
 170         TCCR0B  
= (1 << CS01
);   // Fcpu/8 speed 
 172         puts_P(PSTR("Speaker Enumerated.\r\n")); 
 173         LEDs_SetAllLEDs(LEDMASK_USB_READY
); 
 176 /** Event handler for the USB_HostError event. This indicates that a hardware error occurred while in host mode. */ 
 177 void EVENT_USB_Host_HostError(const uint8_t ErrorCode
) 
 181         printf_P(PSTR(ESC_FG_RED 
"Host Mode Error\r\n" 
 182                                  " -- Error Code %d\r\n" ESC_FG_WHITE
), ErrorCode
); 
 184         LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 188 /** Event handler for the USB_DeviceEnumerationFailed event. This indicates that a problem occurred while 
 189  *  enumerating an attached USB device. 
 191 void EVENT_USB_Host_DeviceEnumerationFailed(const uint8_t ErrorCode
, 
 192                                             const uint8_t SubErrorCode
) 
 194         printf_P(PSTR(ESC_FG_RED 
"Dev Enum Error\r\n" 
 195                                  " -- Error Code %d\r\n" 
 196                                  " -- Sub Error Code %d\r\n" 
 197                                  " -- In State %d\r\n" ESC_FG_WHITE
), ErrorCode
, SubErrorCode
, USB_HostState
); 
 199         LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 202 /** ISR to handle the reloading of the endpoint with the next sample. */ 
 203 ISR(TIMER0_COMPA_vect
, ISR_BLOCK
) 
 205         uint8_t PrevPipe 
= Pipe_GetCurrentPipe(); 
 207         Pipe_SelectPipe(AUDIO_DATA_OUT_PIPE
); 
 210         /* Check if the current pipe can be written to (device ready for more data) */ 
 211         if (Pipe_IsOUTReady()) 
 215                 #if defined(USE_TEST_TONE) 
 216                         static uint8_t SquareWaveSampleCount
; 
 217                         static int16_t CurrentWaveValue
; 
 219                         /* In test tone mode, generate a square wave at 1/256 of the sample rate */ 
 220                         if (SquareWaveSampleCount
++ == 0xFF) 
 221                           CurrentWaveValue 
^= 0x8000; 
 223                         /* Only generate audio if the board button is being pressed */ 
 224                         AudioSample 
= (Buttons_GetStatus() & BUTTONS_BUTTON1
) ? CurrentWaveValue 
: 0; 
 226                         /* Audio sample is ADC value scaled to fit the entire range */ 
 227                         AudioSample 
= ((SAMPLE_MAX_RANGE 
/ ADC_MAX_RANGE
) * ADC_GetResult()); 
 229                         #if defined(MICROPHONE_BIASED_TO_HALF_RAIL) 
 230                         /* Microphone is biased to half rail voltage, subtract the bias from the sample value */ 
 231                         AudioSample 
-= (SAMPLE_MAX_RANGE 
/ 2); 
 235                 Pipe_Write_16_LE(AudioSample
); 
 236                 Pipe_Write_16_LE(AudioSample
); 
 238                 if (!(Pipe_IsReadWriteAllowed())) 
 243         Pipe_SelectPipe(PrevPipe
);