The T-Beam modules I roginally bought for a little job came with Meshtastic pre-installed. At the time I didn’t need that so I re-flashed with the LoRa APRS firmware. Now that the need for lots of LoRa APRS modules has gone away I thought I’d revisit the Meshtstaic idea.

Re-flashing

To be honest I didn’t really have a need for an offline messaging system but if I’ve got the hardware then why not (ignoring the poor RF QTH). But, hey ho, lets have a go at it. The flashing method should be pretty simple. Use the web based tool which looks a bit like Balena Etcher on a web page tbh. But being on a linux machine it wants Chrome (didn’t seem to work with Chromium) so I broke out an older windows machine and it was pretty straightforward. Install some drivers, slect the COM port then flash. Job done.

Using the Android app

Apart from the batteries being completely flat in the modules all I had to do was install the Android software. Just choose your preferred method then get on with it. Here’s where I got a little bit of a ‘Eh?’ feeling

So the app works, its just not as obvious to me as it could be. You need to navigate to a node and connect to it and then use that node to communicate with another node. Once you’ve got that in your head its all gravy.

Web app

A nice feature is that there is a web app that you can use if the device is an ESP32 one (which mine is). So it works nicely to do the node configuration and messaging part.

Do they work?

Well yes they do, but, if like me, you don’t live too close to lots of other people or the node is located in an RF sinkhole (again like me) then you could end up shouting into the void. I did take mine on a little road trip to Nottingham-ish but never really found any othe rnodes or really had the time to look closely for any. So its the same things as you might imaging for APRS. If there aren’t any users within range then there’s little to be gained.

So, about range, how far can it go? To be fair I’m not really sure. The 100mW APRS message went well over 3 miles with a very unscientific test. I perhaps need to look into this a bit more.

The next question is ‘Is it a keeper?’. I reckon so. I probably want a solar powered version that I can put in a box up high. Its just a question of measuring consumption and working out what size panel I need. I can’t image it’ll need a big one. So the to do list looks a bit like this:

  • Get a better GPS antenna - the little one has all the performance you don’t really need
  • Work out consumption and find the right panel
  • Have a look at the nRF types which use loads less power and no GPS for a proper low power device
  • Make a bit of a song and dance about it so there might be a few more nodes kicking about