USBD_CDC_ACM behaves different between SEGGER and Keil compiles

[Jes]

Hello Technical Support team,

I have a strange problem at the moment. I am currently using the USBD_CDC_ACM driver on the nRF52480 dongle hardware. Software SDK version is 15.2. Softdevice S140

The application basically sends plain text data packets to a serial terminal. If I compile the application in SEGGER Embedded Studio the transmission of data works fine, but the same code compiled under Keil I get some wrong characters coming out on the terminal as shown in the picture below.

Do you have any ideas on how this can occur? I suspect is something to do with flow control. I tried to look in the driver to see where the communications parameters are set in code but are unable to find them. Can you please lead me into the right direction.

Regards,

Jes

[ovrebekk]

Hi Jes

How is the data generated on the nRF52 side?

Is it all generated locally, or is it based on some sensor sampling or similar?

Are you able to reproduce the issue with the standard CDC example, or is the code very different?

Have you tried to reproduce it on the nRF52840DK?

Best regards
Torbjørn