serial LTE modem bricks

[d4L]

Hello. For a long time I see that nrf9160 Serial LTE modem examples are not stable, tested few times in a year.At very begininng   I have customized for my  own needs SLM application and it works fine (2020 May source code). At least it works stable with 460800 baud rate, standard AT#XSEND, AT#XRECV commands.
But now I wanted to find out new updates in this SLM firmware and test it with nrf9160 B1 new hardware. It is not stable at all. Just bricks randomly on AT#XRECV =0 (with zero timeout),modem becomes unresponsive to any other AT command...
I am using latest modem firmware 1.3 and latest (July 20 available) source code from

origin    github.com/.../sdk-nrf (fetch)
origin    github.com/.../sdk-nrf (push)

master branch

I have b1 and b0 HW revisions nRF9160 dev kits. Both behaves similar, just randomly bricks on AT#XRECV =0 command.

When I am changing baud rate of UART communication higher than 115200b/s modem bricks fasterm even after few received bytes with AT#XRECV =0 command...

[d4L]

Okay, I have tested with newest master branch. Defined CONFIG_SLM_EXTERNAL_XTAL as recommended. Where trying with 115200 baudrate.
AT#XRECV=1 with 1s timeout works more stable, did not noticed any hanging.But  with 921600 baud rate it still hangs.
But after many tests (with 115200 baud rate) still noticed few times that modem bricks on AT#XCONNECT command, but very rarely. Btw tested newest AT#XSEND without arguments, it works nice, versions above did not had that direct mode which can be stopped with special characters.

[Carl Richard]

Hello again, D4L!

Thanks for the update. Good to hear that it works better now! We'll look into the baud rate issues.

And thanks for the input, Jun!

Best regards,
Carl Richard