Hi Linn,
Here’s the information for your reference about the Audio loop (applicable to both Analog and Digital) :
1)Analog loop intend to test the connection of MIC_P/N to SPK_P/N of analog audio path for production purpose, just to verify the audio function is good to ensure the assembly is good.
2) Digital loop intend to test the connection of PCM interface from PCM_IN to PCM_OUT for production purpose, just to verify the digital audio function is good to ensure the assembly is good.
To check this loop you need a PCM source to inject digital data in PCM_IN and retrieve the data at PCM_OUT.
Here’s the AT example for the test:
1)AT commands: Analog audio loop (Make sure switch is set to ANALOG side in Dev-kit)
AT+WMAUDIOLOOP=1,0,0—> enable audio loop, with Main Mic (Tx organ = 0) and Main Spk (Rx organ = 0)
OK
AT+WMAUDIOLOOP=0,0,0—> disable audio loop (=0 should be enough)
OK
2) AT commands: PCM audio loop (Make sure switch is set to PCM side in Dev -kit)
AT+WMAUDIOLOOP=1,4,8—> enable audio loop, with PCM organ (Tx organ = 4 and Rx organ = 8)
OK
AT+WMAUDIOLOOP=0,4,8—> disable audio loop (=0 should be enough)
OK
is not required before AT+WMAUDIOLOOP.
Please be aware that Analog and PCM loop modes are Test modes (to check the integrity of Tx/Rx paths), it means that Audio framework is in Test mode.
Test mode does not work simultaneously with Normal mode (Voice Call, Playback, Tone Generation, and Recording).
Test mode and Normal mode are mutual exclusive. Trying to mix Test modes with Normal modes can lead to unpredictable behavior of the Audio framework.
Thanks and Regards,
Rex