Add flow control for IN transfer.

examples/device/audio_4_channel_mic/src/main.c

@@ -69,8 +69,13 @@ uint8_t clkValid;
 audio_control_range_2_n_t(1) volumeRng[CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX+1]; 			// Volume range state
 audio_control_range_4_n_t(1) sampleFreqRng; 						// Sample frequency range state
 
+#if CFG_TUD_AUDIO_ENABLE_ENCODING
 // Audio test data, each buffer contains 2 channels, buffer[0] for CH0-1, buffer[1] for CH1-2
 uint16_t i2s_dummy_buffer[CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO][CFG_TUD_AUDIO_FUNC_1_TX_SUPP_SW_FIFO_SZ/2];   // Ensure half word aligned
+#else
+// Audio test data, 4 channels muxed together, buffer[0] for CH0, buffer[1] for CH1, buffer[2] for CH2, buffer[3] for CH3
+uint16_t i2s_dummy_buffer[CFG_TUD_AUDIO_EP_SZ_IN];   // Ensure half word aligned
+#endif
 
 void led_blinking_task(void);
 void audio_task(void);
@@ -97,6 +102,7 @@ int main(void)
   sampleFreqRng.subrange[0].bRes = 0;
 
   // Generate dummy data
+#if CFG_TUD_AUDIO_ENABLE_ENCODING
   uint16_t * p_buff = i2s_dummy_buffer[0];
   uint16_t dataVal = 1;
   for (uint16_t cnt = 0; cnt < AUDIO_SAMPLE_RATE/1000; cnt++)
@@ -116,6 +122,23 @@ int main(void)
     float t = 2*3.1415f * cnt / (AUDIO_SAMPLE_RATE/1000);
     *p_buff++ = (uint16_t)(sinf(t) * 25) + 200;
   }
+#else
+  uint16_t * p_buff = i2s_dummy_buffer;
+  uint16_t dataVal = 1;
+  for (uint16_t cnt = 0; cnt < AUDIO_SAMPLE_RATE/1000; cnt++)
+  {
+    // CH0 saw wave
+    *p_buff++ = dataVal;
+    // CH1 inverted saw wave
+    *p_buff++ = 60 + AUDIO_SAMPLE_RATE/1000 - dataVal;
+    dataVal++;
+    // CH3 square wave
+    *p_buff++ = cnt < (AUDIO_SAMPLE_RATE/1000/2) ? 120:170;
+    // CH4 sinus wave
+    float t = 2*3.1415f * cnt / (AUDIO_SAMPLE_RATE/1000);
+    *p_buff++ = (uint16_t)(sinf(t) * 25) + 200;
+  }
+#endif
 
   while (1)
   {
@@ -384,6 +407,8 @@ bool tud_audio_get_req_entity_cb(uint8_t rhport, tusb_control_request_t const *
         {
           case AUDIO_CS_REQ_CUR:
             TU_LOG2("    Get Sample Freq.\r\n");
+            // Set sample rate for flow control
+            tud_audio_set_tx_flow_control(sampFreq);
             return tud_control_xfer(rhport, p_request, &sampFreq, sizeof(sampFreq));
 
           case AUDIO_CS_REQ_RANGE:
@@ -429,12 +454,15 @@ bool tud_audio_tx_done_pre_load_cb(uint8_t rhport, uint8_t itf, uint8_t ep_in, u
   //    tud_audio_write_support_ff(channel, data, samples * N_BYTES_PER_SAMPLE * N_CHANNEL_PER_FIFO);
   // }
 
+#if CFG_TUD_AUDIO_ENABLE_ENCODING
   // Write I2S buffer into FIFO
   for (uint8_t cnt=0; cnt < 2; cnt++)
   {
     tud_audio_write_support_ff(cnt, i2s_dummy_buffer[cnt], AUDIO_SAMPLE_RATE/1000 * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_CHANNEL_PER_FIFO_TX);
   }
-
+#else
+  tud_audio_write(i2s_dummy_buffer, AUDIO_SAMPLE_RATE/1000 * CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX * CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX);
+#endif
   return true;
 }
 

examples/device/audio_4_channel_mic/src/plot_audio_samples.py

@@ -10,11 +10,11 @@ if __name__ == '__main__':
     # print(sd.query_devices())
 
     fs = 48000  		# Sample rate
-    duration = 20e-3   # Duration of recording
+    duration = 1   # Duration of recording
 
     if platform.system() == 'Windows':
         # WDM-KS is needed since there are more than one MicNode device APIs (at least in Windows)
-        device = 'Microphone (MicNode_4_Ch), Windows WDM-KS'
+        device = 'Microphone (MicNode_4_Ch), Windows WASAPI'
     elif platform.system() == 'Darwin':
         device = 'MicNode_4_Ch'
     else:
@@ -28,8 +28,7 @@ if __name__ == '__main__':
 
     time = np.arange(0, duration, 1 / fs)  # time vector
     # strip starting zero
-    myrecording = myrecording[100:]
-    time = time[100:]
+
     plt.plot(time, myrecording)
     plt.xlabel('Time [s]')
     plt.ylabel('Amplitude')

examples/device/audio_4_channel_mic/src/tusb_config.h

@@ -114,14 +114,25 @@ extern "C" {
 #define CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX    2         // This value is not required by the driver, it parses this information from the descriptor once the alternate interface is set by the host - we use it for the setup
 #define CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX            4         // This value is not required by the driver, it parses this information from the descriptor once the alternate interface is set by the host - we use it for the setup
 #define CFG_TUD_AUDIO_EP_SZ_IN                        TUD_AUDIO_EP_SIZE(CFG_TUD_AUDIO_FUNC_1_SAMPLE_RATE, CFG_TUD_AUDIO_FUNC_1_N_BYTES_PER_SAMPLE_TX, CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX)
+
+#define CFG_TUD_AUDIO_ENABLE_ENCODING                 0
+
+#if CFG_TUD_AUDIO_ENABLE_ENCODING
+
 #define CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX             CFG_TUD_AUDIO_EP_SZ_IN
 #define CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ          CFG_TUD_AUDIO_EP_SZ_IN
 
-#define CFG_TUD_AUDIO_ENABLE_ENCODING                 1
 #define CFG_TUD_AUDIO_ENABLE_TYPE_I_ENCODING          1
 #define CFG_TUD_AUDIO_FUNC_1_CHANNEL_PER_FIFO_TX      2         // One I2S stream contains two channels, each stream is saved within one support FIFO - this value is currently fixed, the driver does not support a changing value
 #define CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO        (CFG_TUD_AUDIO_FUNC_1_N_CHANNELS_TX / CFG_TUD_AUDIO_FUNC_1_CHANNEL_PER_FIFO_TX)
-#define CFG_TUD_AUDIO_FUNC_1_TX_SUPP_SW_FIFO_SZ       (CFG_TUD_AUDIO_EP_SZ_IN / CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO)
+#define CFG_TUD_AUDIO_FUNC_1_TX_SUPP_SW_FIFO_SZ       4 * (CFG_TUD_AUDIO_EP_SZ_IN / CFG_TUD_AUDIO_FUNC_1_N_TX_SUPP_SW_FIFO)
+
+#else
+
+#define CFG_TUD_AUDIO_FUNC_1_EP_IN_SZ_MAX             4 * CFG_TUD_AUDIO_EP_SZ_IN
+#define CFG_TUD_AUDIO_FUNC_1_EP_IN_SW_BUF_SZ          4 * CFG_TUD_AUDIO_EP_SZ_IN
+
+#endif
 
 #ifdef __cplusplus
 }