BSD Lib impacting serial communication

[dboling]

I am working with a custom hardware device similar to the Thingy91. I am communicating with an external device using COM1 using a binary stream at 38400 N81. (COM0 is assigned to the console.) As with the Thingy, I have a I2C bus instantiated as I2C_2 and a SPI bus as SPI_3. I've tried disabling the I2C and SPI but it doesn't impact the problem.

My application communicates with the external device perfectly until I add CONFIG_BSD_LIBRARY=y. The application then fails to communicate properly although some serial streams get through. I've disabled library trace with CONFIG_BSD_LIBRARY_TRACE_ENABLED=n.

I've tried enabling all the dependencies required by the BSD library. None impact the app until I add the BSD Lib itself.

Is there anything in the BSD library that would impact serial communication? I apologize for the vague question but I've been fighting this bug for days.

Doug

[Simon]

Could you try to enable flow control for the uart instance connected to the exernal device? That may make the communication more stable. On the nRF9160 side you can enable it using an overlay file like it's done here: nrf/applications/serial_lte_modem/nrf9160dk_nrf9160ns.overlay.

Best regards,

Simon

[Simon]

You could take a look at the LPUART sample as well, which uses software flow control, and require much less power than hardware flow control.

[dboling]

The problem ended up being a combination of 2 bugs in board_nonsecure.c for our platform. The first was a failure to update the magpio init code to specify a datagram socket. That failed the routine, that then caused the code to skip initializing a required GPIO.

Thanks for you help. I appreciate how responsive you guys are to queries.

Doug

[Simon]

I'm glad you found the cause!

Always happy to help :)