Passing Audio data (PCM 16 bit) to a USB audio device not from headphones

RE: Passing Audio data (PCM 16 bit) to a USB audio device not from headphones

yoyou — Wed, 03 May 2023 01:22:54 GMT

i've the same porbem in nRF5_SDK_17,

I2S mic 16bit 48Khz stereo transferre to USB AUIDO.

some time app_usbd_audio_class_tx_start() return code 17.

RE: Passing Audio data (PCM 16 bit) to a USB audio device not from headphones

Kenneth — Wed, 25 Sep 2019 20:23:22 GMT

This case seems related to this:
https://devzone.nordicsemi.com/f/nordic-q-a/52242/passing-data-from-pdm-callback-to-usb-audio-device

I suggest to continue there.

RE: Passing Audio data (PCM 16 bit) to a USB audio device not from headphones

Or — Sun, 22 Sep 2019 10:55:26 GMT

After debugging the SDK and checking why I get NRF_ERROR_INVALID_STATE when I call app_usbd_audio_class_tx_start() I found out that it is returned from inside the following if statement:

if (!nrf_drv_usbd_ep_enable_check(ep))
{
    return NRF_ERROR_INVALID_STATE;
}

inside the file "nRF5_SDK_15.3.0/components/libraries/usbd/app_usbd.c" inside function app_usbd_ep_transfer() (line 1820).

What can disable the endpoint ? why does it happen in the middle of using it ?

Passing Audio data (PCM 16 bit) to a USB audio device *not* from headphones

RE: Passing Audio data (PCM 16 bit) to a USB audio device *not* from headphones

RE: Passing Audio data (PCM 16 bit) to a USB audio device *not* from headphones

RE: Passing Audio data (PCM 16 bit) to a USB audio device *not* from headphones

Passing Audio data (PCM 16 bit) to a USB audio device not from headphones

RE: Passing Audio data (PCM 16 bit) to a USB audio device not from headphones

RE: Passing Audio data (PCM 16 bit) to a USB audio device not from headphones

RE: Passing Audio data (PCM 16 bit) to a USB audio device not from headphones