cancel
Showing results for 
Search instead for 
Did you mean: 

STM32CubeExpansion_USBAudioStreaming_V1.0.0 and "Line in"

dpn
Associate II

Hello,

We have purchased the STM32F769I-DISCO KIT as we plan to use STM32F769I in USB audio IN/OUT application.

I am trying to make "STM32CubeExpansion_USBAudioStreaming_V1.0.0" example provided by ST working. So far:

  • I have configured the above example in a configuration STM32F769I-DISCO_UAC10-PLAY and tested the USB stream OUT successfully.
  • I have configured the example as STM32F769I-DISCO_UAC10-REC. The recordings using the MEMS microphones on the KIT is working fine as expected.

In our application we will have a codec similar as the one (WM8994) on the STM32F769I-DISCO KIT and we need to stream IN and OUT thru that codec. On the STM32F769I-DISCO KIT there is "Line in" connector to the WM8994 codec. And I am trying to make recordings working using the "Line in". As the example uses the PDM MEMS microphones I have to make some changes.

In the above example I have noticed a macro which seems to switch between the MEMS microphones and the WM8994 "Line in" (INPUT_DEVICE_ANALOG_MIC)

In the file stm32f769i_discovery_audio_ex.c I have modified the lines :

...

static uint16_t    AudioIn_Device = INPUT_DEVICE_ANALOG_MIC;

...

return BSP_AUDIO_IN_InitEx(INPUT_DEVICE_ANALOG_MIC, AudioFreq, BitRes, ChnlNbr);

...

I still have in my project preprocessor the variables

...

USE_USB_AUDIO_RECORDING=1

USE_AUDIO_DFSDM_MEMS_MIC=1

Pretty much this is what I see needs to be adjusted but still my recordings from "Line in" does not work. I recorded only silence.

Anyone who knows what may be wrong?

Thank you

Dimitar

1 REPLY 1
MM..1
Chief III

No your changed code not help . Example record is prepared only for DIGITAL MIC.

You need write your own code for record line in.