One my friends from middle school had the idea to create a cheap device that can measure and collect the LTE signal levels.
We got a suitable devboard for the prototype and I ported OpenWRT to it. I also needed to modify the LTE module’s driver to make it work.
The user-space software sent the data to our server using MQTT and this method also provided the ability to have multiple devices. The project is still in progress so I won’t write more details but I can show an example image of the results:
