No Response from Thingy91 via Serial Terminal Commands

[xr47]

Hello Nordic Community,

I installed the serial LTE modem application on my Thingy:91 so that I may use it as a standalone modem. Using minicom on my Linux machine, whenever I send an AT command I get no response from the device. However, if I use the LTE Link Monitor software to send a command while keeping the minicom session open, I get a response from the device within the minicom session instead of in the LTE Link Monitor window. I have also tried using PuTTY but I get the exact same result. Any suggestions or ideas on what might cause this issue and how to resolve it?

Thank you!

Serial Terminal Configuration:

Baud Rate: 115200

Flow Control: None

CR+LF enabled

8 Data Bits

1 Stop Bit

[Øyvind]

Hello, 

Did you program the Serial LTE Modem from the precompiled package for Thingy:91 or did you build from the nRF Connect SDK? If the latter, what version of the SDK are you using? I tested with building from our latest tag, v2.2.0 and programmed the Thingy:91. Running the LTE Link Monitor gave me no issues with the connection. Do note that it should not be connected to two serial terminals at once. 

Kind regards,
Øyvind

[xr47]

I built it from the precompiled package. The LTE Link Monitor is not my issue. The issue I have is that using a serial terminal, such as minicom or PuTTY, the modem does not respond to a single command; not one. However, when I use the LTE Link monitor it functions as expected. Even further, if I use the LTE Link monitor in conjunction with a serial terminal like minicom or PuTTY, I can send commands via the LTE Link Monitor and then receive the appropriate response via minicom or PuTYY; whichever I have open. I want to forego using the LTE Link Monitor entirely and only use a serial terminal application due to the type of development I am doing. Hopefully that clears up the context for you.

[Øyvind]

Thanks for clarifying. I see the same on my side. Looks like an issue with the Serial LTE Modem. I've tried to build and flash from the SDK and to program a precompiled .hex with same result. 

Will need some more time to investigate.

-Øyvind

[Øyvind]

Hello again, the Serial LTE Modem documentation states the following under Connecting with a PC

 

I've tested here with minicom and PuTTY, and it seems to work as it should. 

Let me know how it works for you.

Kind regards,
Øyvind