Board Level Validation

Follow the steps below to validate board-level settings for connecting to external codecs.
  1. Make sure OS can boot and the audio card has been registered successfully.
    1. Use the command cat /proc/asound/cards to check the existing audio cards.
    2. Use aplay -l to check the audio playback device.
    3. Use arecord -l to check the audio record device.
  2. Make sure I2C is working properly.
    • Use the command i2cdetect to search codec device (wm8960’s address is 0x1a )
      Figure 1. I2C Detect
      Note: UU in the above screen indicates wm8960 is present.
    • Use the debug nodes of the external codec to read and write the registers for I2C communication debug.
      mount -t debugfs none /mnt
      cat /mnt/wm8960_reg
  3. Verify the playback and record functions.

    Usage:

    Playback: 
    aplay -Dhw:0,1 -f S32_LE -r16000 -t wav sound_32b_16k.wav
    Record: 
    arecord -Dhw:0,0 -f S32_LE -r16000 -c2 -d 10 -t wav sound_32b_16k.wav