nRF9160 AT client UART0 pins reassignment issue

[Smart.Enrg]

Hi,

I have a custom board based on nRF9160 for which I created custom .dts following porting guide.
It seems TX isn't sending anything (stay close to 0V) - config I have is: tx-pin = <8>; rx-pin = <9>; 
for &uart0, no handshake, reset level at 2.7V.
Checked prj.conf and .config they settings there seem alright. Please advise, what I might be missing here?
Thanks.

[Smart.Enrg]

Hi Simon,

Following Erase All in nRF connect/ programmer - do I need to flash modem f/w, before flashing my app (SLM or AT client) hex?

Best,
SE

[Simon]

Could you try to configure the UART according to External MCU configuration?

It says that flow control should be used, so you could try to either add RTS and CTS in your custom board folder or through an overlay file.

You could test it with an nRF52 DK first, to make sure it's working, then swap it with your external MCU.

Best regards,

Simon