CLI RTT Monitor Mode Issue

[Jason Hendrix]

Monitor mode debugging seems to have crippled the CLI over RTT.

Edit: Reflecting further, ignoring the black vs white background symptom - the issue might simply be that the CLI RTT output is broken.

I have a project that implements the CLI over RTT using the SDK CLI library. Today I implemented the monitor mode debugging as described in this link: devzone.nordicsemi.com/.../ This works great - however, it seems to have negatively affected the RTT CLI. With monitor mode debugging enabled, I can't see CLI output. I can see RTT output from the NRF_LOG macros, however. Though it doesn't display the CLI prompt, commands entered in the Debug Terminal ARE received by my app. Also, the background of the Debug terminal turned from black to white (see attachments - black good, white bad).
Disabling the Debug Terminal and connecting with PuTTY to the RTT port yields similar results. I can see NRF_LOG messages but not CLI output or the CLI prompt. Furthermore, the local echo seems broken. Commands again are taking effect in my program, but you can't see your commands in the PuTTY window.
Is there anyway to fix this? I'm working on a custom board based on the nRF52832. I'm developing on Win 8.1 using SES and a J-Link Plus. SDK version 14.1.

[Jakub Rzeszutko]

Hi Jason,

This is a known problem, quote from Segger forum: "The issue is that RTT data can only be grabbed once from J-Link. So when there are multiple terminals "competing" data will be spread or even lost among them."

Easy fix for that is to deactivate RTT via Segger Embedded Studio:

Project settings->Debug->Debugger->RTT Enable-> Set to No

What is more, SES RTT terminal is not handling VT100 commands at all so you need to run PuTTY to use CLI.

[Jason Hendrix]

Thanks for the response Jakub, but it doesn't it doesn't address my issue, which is that Monitor Mode debugging is suppressing RTT CLI output. I'm not trying to run PuTTY and Debug Terminal simultaneously. Note that I say "Disabling the Debug Terminal and connecting with PuTTY". Both PuTTY and Debug Terminal behaviosr are mentioned just to describe the debugging I've done so far.