ESP32 Forum

I work on a USB to I2S_TDM bridge supporting 8 channels. The platform will be ESP32-P4.

I use the Espressif esp_device_uac component from ESP IoT Solutions (https://components.espressif.com/compon ... device_uac), which relies on TinyUSB ^0.17.0~2 (TinyUSB last native version is 20.0

The application appear to work when plugged in a Linux Host. I can play a 8 channel audio track. But it doesn't work when plugged in a windows host (works however with 2 channels/stereo). There seems to be an out of range value.

I activated the TinyUSB debug. I got also information from the Windows side using their tracing tool. Both are attached.

The issue seems related to the setting of the sampling frequency/clock. Windows seems to stop progress on "Supported sampling frequencies:" log.

On the Tiny USB side:

USBD Setup Received A1 02 00 01 00 04 00 01
AUDIO control request
Clock get 1 freq ranges
Range 0 (48000, 48000, 0)
Queue EP 80 with 14 bytes ...
USBD Xfer Complete on EP 80 with 14 bytes
AUDIO control complete
Queue EP 00 with 0 bytes ...
USBD Xfer Complete on EP 00 with 0 bytes

USBD Setup Received 80 06 05 03 09 04 02 00
Get Descriptor String[5]
Queue EP 80 with 2 bytes ...
USBD Xfer Complete on EP 80 with 2 bytes
Queue EP 00 with 0 bytes ...
USBD Xfer Complete on EP 00 with 0 bytes

USBD Setup Received 80 06 05 03 09 04 10 00
Get Descriptor String[5]
Queue EP 80 with 16 bytes ...
USBD Xfer Complete on EP 80 with 16 bytes
Queue EP 00 with 0 bytes ...
USBD Xfer Complete on EP 00 with 0 bytes
I (13338) i2s_usb: MCLK: 18432000, delta: 0, buffer water mark: 0%
USBD Suspend : Remote Wakeup = 0
I (13827) usbd_uac: USB suspended

For completeness, I also add the descriptors as seen by Linux host.

Help would be very welcomed.
Best regards,
JMF111

The extra sample slot needed for Async feedback implementation for the EP maxsize is hard coded to +4 in the esp_device_uac code, which is OK for stereo but not for higher number of channels. Once addressed, Windows recognises the device.