martes, 16 de marzo de 2021

On configuring RAK LoRa devices, or how to avoid their Windows-only serial application

tl;dr: use a serial terminal which can buffer input and send it all at once, lines should end with \CR\LF.

I'm am currently working on bringing up a LoRa network in Bahía Blanca. Parts of the nodes I need to set up are made by RAK Wireless.

According to their documentation the nodes can be configured by using a serial connection to them. So I quickly turned to minicom for it, with no avail. Somehow I could read whatever the device was writing to my machine but could not write any commands back to it.

In order to get the issue solved I switched to running their RAK serial port tool under wine. Making it work made me download and install a huge amount of Windows libraries and tools, but in the end I wanted a Linux-only solution.

After much  digging the web, trial and error I've found a way to solve this:

  1. Commands should end with \CR\LF.
  2. The command needs to be sent quickly, all in one go, trough the serial port. This means it can't be typed and sent as normal serial consoles.

The solution for (1) in minicom is easy, but I don't know if minicom is capable of doing the buffering thing, so I went to use cutecom, for which one has to enter the input and send it all at once.