Error Code 11 from app_usbd_cdc_acm_write

[ApurvaPatel]

Hello. I am trying to scan for BLE packets and write them out through USBD using nRF5 SDK v15.3.0. I am calling app_usbd_cdc_acm_write() in scan_evt_handler when an event is reported. Occasionally, the app_usbd_cdc_acm_write() function returns 11, which is the error code for NRF_ERROR_INVALID_DATA. Whenever this error is encountered, a part of the two packets sent immediately before and after this error get combined, as observed on the device receiving the packet. What is the cause of this behavior? I was unable to find where NRF_ERROR_INVALID_DATA is reported in the app_usbd_cdc_acm_write() function.

[Vidar Berg]

Hello, I couldn't  find out where NRF_ERROR_INVALID_DATA was returned either. Could it be that the error 11 is really 0x11 hex and thus the same NRF_ERROR_BUSY? If not, I will have to take a closer look.

Best regards,

Vidar

[ApurvaPatel]

Yes, it was being printed in hex. I will refer to other posts regarding NRF_ERROR_BUSY from app_usbd_cdc_acm_write(). Thank you!

Edit: Waiting for APP_USBD_CDC_ACM_USER_EVT_TX_DONE helped to resolve my issue.