NCS/9160: do I have to have uart0 as console?

[bluebeam]

I'm moving from NRF9160DK to a custom board, where it has no UART. I plan to just use RTT for debugging messages.

However, I found if I delete the section which defines uart0 in the nrf9160dk_nrf9160_common.dts file, I won't be able to see RTT output in the JLinkRTTViewer. Nor can I set the uart0 to "disabled", or comment out "chosen{ zephyr,console=&uart0}" at the top of the file. (I'm creating my own DTS file but so far it's just a copy of the nrf9160dk_nrf9160_common.dts)

In my prj.comf, I already has these:

CONFIG_LOG=y

CONFIG_LOG_MODE_MINIMAL=n

CONFIG_LOG_MODE_IMMEDIATE=n

CONFIG_LOG_MODE_DEFERRED=y

CONFIG_LOG_PROCESS_THREAD=y

CONFIG_LOG_BUFFER_SIZE=8192

CONFIG_LOG_FRONTEND=n

CONFIG_LOG_BACKEND_UART=n

# Segger RTT

CONFIG_USE_SEGGER_RTT=y

CONFIG_RTT_CONSOLE=y

CONFIG_UART_CONSOLE=n

CONFIG_LOG_BACKEND_RTT=y

It appears that setting the LOG_BACKENG to UART or RTT doesn't affect anything.

So currently I just set uart0 to use two spare pin as tx/rx so the project can compile. And I can see messages in the RTT viewer. I'm not sure what is wrong, or it has to be this way.

I'm using NCS 1.7.1.

Thanks for any help!

[DamoL]

Check your prj.conf in you SPM folder. I had CONFIG_SERIAL=y within that and that was overwriting the CONFIG_SERIAL=n in my project. 

I went round the houses creating functions to disable UART0 in runtime before I realised that was there.

[bluebeam]

I don't think I have a SPM folder. I only have one prj.conf within my source folder.

[DamoL]

Ah yes sorry. I am looking at a different project from when I first had this issue. 

Looks like you already found it, but you  nrf9160dk_nrf9160ns_defconfig can be edited for your board folder. 

For reference mine now looks like this. It will probably get rid of the error you have above.

# SPDX-License-Identifier: Apache-2.0

CONFIG_SOC_SERIES_NRF91X=y
CONFIG_SOC_NRF9160_SICA=y
CONFIG_BOARD_NRF9160DK_NRF9160NS=y

# Enable MPU
CONFIG_ARM_MPU=y

# Enable hardware stack protection
CONFIG_HW_STACK_PROTECTION=y

# Enable TrustZone-M
CONFIG_ARM_TRUSTZONE_M=y

# This Board implies building Non-Secure firmware
CONFIG_TRUSTED_EXECUTION_NONSECURE=y

# enable GPIO
CONFIG_GPIO=y

# # Enable uart driver            #COMMENT THIS OUT
# CONFIG_SERIAL=y                 #COMMENT THIS OUT
#                                 #COMMENT THIS OUT
# # enable console                #COMMENT THIS OUT
# CONFIG_CONSOLE=y                #COMMENT THIS OUT
# CONFIG_UART_CONSOLE=y           #COMMENT THIS OUT

[bluebeam]

I did try to comment out those lines as you mentioned. But I found I have to at least keep the line "CONFIG_CONSOLE=y" to have RTT working. Otherwise the RTT viewer shows nothing.

Strange. There's definitely some complicated relationship between those CONFIGs.