6.3 Test 3: Testing the SPDIF Receiver using ALSA and a USB Audio Extender

In this test, record the audio input from the mono microphone connected to a USB audio extender, transmit it through the S/PDIF-Out of the USB audio extender, and record an audio file received via the SPDIF RX peripheral using the ALSA utility on SAMA7G54-EK.

The SPDIF receiver is the component that receives the digital audio signal, and it decodes the SPDIF signal back into an audio signal that the device can process.

1. Plug the audio splitter cable into the headphone jack.
2. Connect the microphone plug from the audio splitter to the MIC 1 In port (right channel).
   Important: To split the audio and microphone signals, use a headphone audio splitter. Connect the microphone cable from the splitter to the 3.5 mm mono jack input on the USB audio extender.