Update the Low Level Audio Input and Audio Output demos to support multiple sample...

[pub/USBasp.git] / Demos / Device / LowLevel / AudioOutput / AudioOutput.c

diff --git a/Demos/Device/LowLevel/AudioOutput/AudioOutput.c b/Demos/Device/LowLevel/AudioOutput/AudioOutput.c
index 22cfac4..c5d9363 100644 (file)
--- a/Demos/Device/LowLevel/AudioOutput/AudioOutput.c
+++ b/Demos/Device/LowLevel/AudioOutput/AudioOutput.c
@@ -39,6 +39,9 @@
 /** Flag to indicate if the streaming audio alternative interface has been selected by the host. */
 static bool StreamingAudioInterfaceSelected = false;
 
+/** Current audio sampling frequency of the streaming audio endpoint. */
+static uint32_t CurrentAudioSampleFrequency = 48000;
+
 
 /** Main program entry point. This routine contains the overall program flow, including initial
  *  setup of all components and the main program loop.
@@ -81,7 +84,7 @@ void EVENT_USB_Device_Connect(void)
 
        /* Sample reload timer initialization */
        TIMSK0 = (1 << OCIE0A);
-       OCR0A  = ((F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1);
+       OCR0A  = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
        TCCR0A = (1 << WGM01);  // CTC mode
        TCCR0B = (1 << CS01);   // Fcpu/8 speed
 
@@ -178,6 +181,57 @@ void EVENT_USB_Device_ControlRequest(void)
                                Endpoint_ClearSETUP();
                                Endpoint_ClearStatusStage();
                        }
+
+                       break;
+               case AUDIO_REQ_SetCurrent:
+                       if (USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_ENDPOINT))
+                       {
+                               /* Extract out the relevant request information to get the target Endpoint index and control being set */
+                               uint8_t EndpointIndex   = (uint8_t)USB_ControlRequest.wIndex;
+                               uint8_t EndpointControl = (USB_ControlRequest.wValue >> 8);
+                               
+                               /* Only handle SET CURRENT requests to the audio endpoint's sample frequency property */
+                               if ((EndpointIndex == AUDIO_STREAM_EPNUM) && (EndpointControl == AUDIO_EPCONTROL_SamplingFreq))
+                               {
+                                       uint8_t SampleRate[3];
+                               
+                                       Endpoint_ClearSETUP();
+                                       Endpoint_Read_Control_Stream_LE(SampleRate, sizeof(SampleRate));
+                                       Endpoint_ClearOUT();
+                                       
+                                       /* Set the new sampling frequency to the value given by the host */
+                                       CurrentAudioSampleFrequency = (((uint32_t)SampleRate[2] << 16) | ((uint32_t)SampleRate[1] << 8) | (uint32_t)SampleRate[0]);
+
+                                       /* Adjust sample reload timer to the new frequency */
+                                       OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
+                               }
+                       }
+                       
+                       break;
+               case AUDIO_REQ_GetCurrent:
+                       if (USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_ENDPOINT))
+                       {
+                               /* Extract out the relevant request information to get the target Endpoint index and control being retrieved */
+                               uint8_t EndpointIndex   = (uint8_t)USB_ControlRequest.wIndex;
+                               uint8_t EndpointControl = (USB_ControlRequest.wValue >> 8);
+                               
+                               /* Only handle GET CURRENT requests to the audio endpoint's sample frequency property */
+                               if ((EndpointIndex == AUDIO_STREAM_EPNUM) && (EndpointControl == AUDIO_EPCONTROL_SamplingFreq))
+                               {
+                                       uint8_t SampleRate[3];
+                                       
+                                       /* Convert the sampling rate value into the 24-bit format the host expects for the property */
+                                       SampleRate[2] = (CurrentAudioSampleFrequency >> 16);
+                                       SampleRate[1] = (CurrentAudioSampleFrequency >> 8);
+                                       SampleRate[0] = (CurrentAudioSampleFrequency &  0xFF);
+                               
+                                       Endpoint_ClearSETUP();
+                                       Endpoint_Write_Control_Stream_LE(SampleRate, sizeof(SampleRate));
+                                       Endpoint_ClearOUT();                                    
+                               }
+                       }
+
+                       break;
        }
 }