MQTT demo not working

[doncarlos999]

I am trying to run the MQTT demo from here but I just get timed out errors in the LTE link monitor v2.0.2 from nRF connect for Desktop v3.12.1:

2022-11-09T11:41:00.306Z DEBUG Application data folder: /Users/carl/Library/Application Support/nrfconnect/pc-nrfconnect-linkmonitor
2022-11-09T11:41:01.432Z INFO Using nrf-device-lib-js version: 0.4.15
2022-11-09T11:41:01.433Z INFO Using nrf-device-lib version: 0.12.8
2022-11-09T11:41:01.434Z INFO Using nrfjprog DLL version: 10.16.0
2022-11-09T11:41:01.434Z INFO Using JLink version: JLink_V7.66a
2022-11-09T11:41:01.837Z DEBUG App pc-nrfconnect-linkmonitor v2.0.2 official
2022-11-09T11:41:01.837Z DEBUG App path: /Users/carl/.nrfconnect-apps/node_modules/pc-nrfconnect-linkmonitor
2022-11-09T11:41:01.837Z DEBUG nRFConnect 3.12.1, required by the app is (^3.12.0)
2022-11-09T11:41:01.837Z DEBUG nRFConnect path: /Applications/nRF Connect for Desktop.app/Contents/Resources/app.asar
2022-11-09T11:41:01.837Z DEBUG HomeDir: /Users/carl
2022-11-09T11:41:01.838Z DEBUG TmpDir: /var/folders/9g/pb74fdsn79s9bxr_2jc5_hb80000gn/T/
2022-11-09T11:41:03.980Z INFO Modem port is opened
2022-11-09T11:41:08.917Z DEBUG modem >> AT+HELP
2022-11-09T11:41:09.916Z ERROR Error: 'AT+HELP
' timed out
2022-11-09T11:41:14.638Z DEBUG modem >> AT+CONNECT
2022-11-09T11:41:15.640Z ERROR Error: 'AT+CONNECT
' timed out

I tried with firmware built by myself using the docker method (incorporating the C++ library from here) and also with prebuilt thingy:91 binaries from here. I flashed the connectivity-bridge.hex in both cases after turning the device on whilst holding the SW4 button as mentioned in the getting started guide (here). Then flashed the app_signed.hex or firmware.hex after turning the device on whilst holding the SW3 button. Any help with this would be greatly appreciated.

[mmajchrzycki]

First of all, LTE Link Monitor app requires special firmware from nRF Connect SDK (https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/nrf9160/at_client/README.html). Try to build this firmware first, flash it to your nRF91, and then try LTE Link Monitor.

[doncarlos999]

LTE link monitor works with their AT client. Do I need JLink from another board to open Serial Port Terminal to run the AT commands or can I do it by USB? Edit: I was able to access the thingy:91 through USB and picocom