USB_Microphone: not audio output

[jimmyibongo]

Hi everyone.

I am relatively new to working with STM32 devices, and I am currently attempting to design a USB microphone with an analog input using the Nucleo-L476RG development board in combination with the X-NUCLEO-CCA02M2 USB audio expansion board. To configure the system parameters in STM32CubeIDE, I followed the procedure described at the following reference: STM32F4 USB microphone | Details | Hackaday.io.

Using this configuration, the computer successfully recognizes the device as a USB microphone; however, no audio data is being transmitted.

I have attached the relevant configuration files—usbd_audio.c, usbd_audio.h, and main.c—in case someone might help identify any mistakes or oversights in my implementation. The analog signal is acquired through a single ADC channel using DMA with interrupt callbacks. The USB audio streaming is configured for a sampling rate of 48 kHz, and Timer 8 is used to trigger the ADC conversions.

Any assistance or guidance would be greatly appreciated.

Thank you very much.

[FBL]

Hi @jimmyibongo 

First, I recommend you checking X-CUBE-AUDIO-KIT.

Second, since no audio data is being transmitted, could you please provide minimum firmware to test it?

[jimmyibongo]

Hi @FBL 

Bellow I have attached the project.

In the meantime, I will check  X-CUBE-AUDIO-KIT.

Thanks.

[jimmyibongo]

Hi, everyone. 

I'm still unable to solve this.

Using the STM32L476 with the X-NUCLEO-CCA02M2 USB extension, I can detect the Mic (USB configured as a Audio Class. The problem is that I don't get audio at the output. Is there a steps to follow to perfectly configure the USB audio output? which are the function that need to be called, and from where?

I'm trying to follow this notes: Introduction to USB with STM32 - stm32mcu  Is there someone that have been able to run it? Any help and guidance will be great. 

Thanks.