3      Copyright (C) Dean Camera, 2013. 
   5   dean [at] fourwalledcubicle [dot] com 
  10   Copyright 2013  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 disclaims 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 /** 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. 
  43 USB_ClassInfo_Audio_Host_t Speaker_Audio_Interface 
= 
  49                                                 .Address        
= (PIPE_DIR_OUT 
| 2), 
  55 /** Main program entry point. This routine configures the hardware required by the application, then 
  56  *  enters a loop to run the application tasks in sequence. 
  62         puts_P(PSTR(ESC_FG_CYAN 
"Audio Output Host Demo running.\r\n" ESC_FG_WHITE
)); 
  64         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY
); 
  65         GlobalInterruptEnable(); 
  69                 Audio_Host_USBTask(&Speaker_Audio_Interface
); 
  74 /** ISR to handle the reloading of the PWM timer with the next sample. */ 
  75 ISR(TIMER0_COMPA_vect
, ISR_BLOCK
) 
  77         uint8_t PrevPipe 
= Pipe_GetCurrentPipe(); 
  79         /* Check that the USB bus is ready for the next sample to write */ 
  80         if (Audio_Host_IsReadyForNextSample(&Speaker_Audio_Interface
)) 
  84                 #if defined(USE_TEST_TONE) 
  85                         static uint8_t SquareWaveSampleCount
; 
  86                         static int16_t CurrentWaveValue
; 
  88                         /* In test tone mode, generate a square wave at 1/256 of the sample rate */ 
  89                         if (SquareWaveSampleCount
++ == 0xFF) 
  90                           CurrentWaveValue 
^= 0x8000; 
  92                         /* Only generate audio if the board button is being pressed */ 
  93                         AudioSample 
= (Buttons_GetStatus() & BUTTONS_BUTTON1
) ? CurrentWaveValue 
: 0; 
  95                         /* Audio sample is ADC value scaled to fit the entire range */ 
  96                         AudioSample 
= ((SAMPLE_MAX_RANGE 
/ ADC_MAX_RANGE
) * ADC_GetResult()); 
  98                         #if defined(MICROPHONE_BIASED_TO_HALF_RAIL) 
  99                         /* Microphone is biased to half rail voltage, subtract the bias from the sample value */ 
 100                         AudioSample 
-= (SAMPLE_MAX_RANGE 
/ 2); 
 104                 Audio_Host_WriteSample16(&Speaker_Audio_Interface
, AudioSample
); 
 105                 Audio_Host_WriteSample16(&Speaker_Audio_Interface
, AudioSample
); 
 108         Pipe_SelectPipe(PrevPipe
); 
 111 /** Configures the board hardware and chip peripherals for the demo's functionality. */ 
 112 void SetupHardware(void) 
 114 #if (ARCH == ARCH_AVR8) 
 115         /* Disable watchdog if enabled by bootloader/fuses */ 
 116         MCUSR 
&= ~(1 << WDRF
); 
 119         /* Disable clock division */ 
 120         clock_prescale_set(clock_div_1
); 
 123         /* Hardware Initialization */ 
 124         Serial_Init(9600, false); 
 127         ADC_Init(ADC_FREE_RUNNING 
| ADC_PRESCALE_32
); 
 128         ADC_SetupChannel(MIC_IN_ADC_CHANNEL
); 
 131         /* Create a stdio stream for the serial port for stdin and stdout */ 
 132         Serial_CreateStream(NULL
); 
 134         /* Start the ADC conversion in free running mode */ 
 135         ADC_StartReading(ADC_REFERENCE_AVCC 
| ADC_RIGHT_ADJUSTED 
| ADC_GET_CHANNEL_MASK(MIC_IN_ADC_CHANNEL
)); 
 138 /** Event handler for the USB_DeviceAttached event. This indicates that a device has been attached to the host, and 
 139  *  starts the library USB task to begin the enumeration and USB management process. 
 141 void EVENT_USB_Host_DeviceAttached(void) 
 143         puts_P(PSTR("Device Attached.\r\n")); 
 144         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING
); 
 147 /** Event handler for the USB_DeviceUnattached event. This indicates that a device has been removed from the host, and 
 148  *  stops the library USB task management process. 
 150 void EVENT_USB_Host_DeviceUnattached(void) 
 152         puts_P(PSTR("\r\nDevice Unattached.\r\n")); 
 153         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY
); 
 156 /** Event handler for the USB_DeviceEnumerationComplete event. This indicates that a device has been successfully 
 157  *  enumerated by the host and is now ready to be used by the application. 
 159 void EVENT_USB_Host_DeviceEnumerationComplete(void) 
 161         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING
); 
 163         uint16_t ConfigDescriptorSize
; 
 164         uint8_t  ConfigDescriptorData
[512]; 
 166         if (USB_Host_GetDeviceConfigDescriptor(1, &ConfigDescriptorSize
, ConfigDescriptorData
, 
 167                                                sizeof(ConfigDescriptorData
)) != HOST_GETCONFIG_Successful
) 
 169                 puts_P(PSTR("Error Retrieving Configuration Descriptor.\r\n")); 
 170                 LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 174         if (Audio_Host_ConfigurePipes(&Speaker_Audio_Interface
, 
 175                                       ConfigDescriptorSize
, ConfigDescriptorData
) != AUDIO_ENUMERROR_NoError
) 
 177                 puts_P(PSTR("Attached Device Not a Valid Audio Output Device.\r\n")); 
 178                 LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 182         if (USB_Host_SetDeviceConfiguration(1) != HOST_SENDCONTROL_Successful
) 
 184                 puts_P(PSTR("Error Setting Device Configuration.\r\n")); 
 185                 LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 189         if (Audio_Host_StartStopStreaming(&Speaker_Audio_Interface
, true) != HOST_SENDCONTROL_Successful
) 
 191                 puts_P(PSTR("Error Enabling Audio Stream.\r\n")); 
 192                 LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 193                 USB_Host_SetDeviceConfiguration(0); 
 197         USB_Audio_SampleFreq_t SampleRate 
= AUDIO_SAMPLE_FREQ(48000); 
 198         if (Audio_Host_GetSetEndpointProperty(&Speaker_Audio_Interface
, Speaker_Audio_Interface
.Config
.DataOUTPipe
.Address
, 
 199                                               AUDIO_REQ_SetCurrent
, AUDIO_EPCONTROL_SamplingFreq
, 
 200                                               sizeof(SampleRate
), &SampleRate
) != HOST_SENDCONTROL_Successful
) 
 202                 puts_P(PSTR("Error Setting Audio Sampling Frequency.\r\n")); 
 203                 LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 204                 USB_Host_SetDeviceConfiguration(0); 
 208         /* Sample reload timer initialization */ 
 209         TIMSK0  
= (1 << OCIE0A
); 
 210         OCR0A   
= ((F_CPU 
/ 8 / 48000) - 1); 
 211         TCCR0A  
= (1 << WGM01
);  // CTC mode 
 212         TCCR0B  
= (1 << CS01
);   // Fcpu/8 speed 
 214         puts_P(PSTR("Audio Device Enumerated.\r\n")); 
 215         LEDs_SetAllLEDs(LEDMASK_USB_READY
); 
 218 /** Event handler for the USB_HostError event. This indicates that a hardware error occurred while in host mode. */ 
 219 void EVENT_USB_Host_HostError(const uint8_t ErrorCode
) 
 223         printf_P(PSTR(ESC_FG_RED 
"Host Mode Error\r\n" 
 224                                  " -- Error Code %d\r\n" ESC_FG_WHITE
), ErrorCode
); 
 226         LEDs_SetAllLEDs(LEDMASK_USB_ERROR
); 
 230 /** Event handler for the USB_DeviceEnumerationFailed event. This indicates that a problem occurred while 
 231  *  enumerating an attached USB device. 
 233 void EVENT_USB_Host_DeviceEnumerationFailed(const uint8_t ErrorCode
, 
 234                                             const uint8_t SubErrorCode
) 
 236         printf_P(PSTR(ESC_FG_RED 
"Dev Enum Error\r\n" 
 237                                  " -- Error Code %d\r\n" 
 238                                  " -- Sub Error Code %d\r\n" 
 239                                  " -- In State %d\r\n" ESC_FG_WHITE
), ErrorCode
, SubErrorCode
, USB_HostState
); 
 241         LEDs_SetAllLEDs(LEDMASK_USB_ERROR
);