Jeti Telemetry Protocol Updated!

Did you guys notice one thing? Jetimodel have updated the free part of Telemetry Protocol? And all I can say is wohoo! Finally!

No news?

Well, Jetimodel is not known to shout out too much, so it might be good to browse through the site every now and then. Occasional releases of new products can be found on their Facebook page. (I’d really would like to join a “release mailinglist”, Jetimodel, are you listening…?)

Telemetry Protocol – Free and Non-free?

There’s two different protocols available, the one we DIY-guys are using is the free part. This means as an example we cannot create bin-files to integrate for example a sensor to “Model” -> “Device Explorer” menu, we use Jetibox-menus for sensor-settings. In order to get the non-free protocol I would think you’d have to sign NDA with Jetimodel and most likely have the bin-files either created by Jetimodel or at least have them checked by them.

What’s New In Protocol 1.07?

For starters, no release notes, usually there is none for these. So it’s on to manual comparison of old an new protocol description. I found only one update, and what an update is is!

Wohoo! Finally!

New protocol function is something I have wanted to have in Jeti DIY-sensors from day one when I made the RFID Sensor. The RFID-sensor (as does the new Jeti MTAG) is for identifying batteries used in our models. And of course a name would be nice to store in the RFID-tag too. We can write the name to tag, that’s not the issue, but we are not able to send text-strings through telemetry. That is, until now!

Reading the protocol specification reveals a few cool things:

  • Message (string) can be categorized to “Basic info”, “Status message”, “Warning”, Recoverable error” and “nonrecoverable error”
  • Length is apparently not too much limited, we tell the length and the message-string

Here’s the relevant (new) part of telemetry protocol version 1.07:

Jeti Telemetry v1.07

However, we are not fully out of woods yet!

Things To Consider

First of all, to my knowledge none of the available telemetry libraries (to for example Arduino) do not support this yet. Also, we have at the moment no sure way how to show this message (string) in different ways. I would imagine an string with type “Alarm” or “Status message” could pop ups as notification. There is a little hope however, the string is transmitted with same byte number and almost identical structure so some debugging could make this work with minimal changes to libraries.

For us to get for example the battery name written in RFID-tag we have to read the tag, send it to transmitter and find out a way how to show it either with lua or by the transmitter itself.

Latest lua API (version 1.5) has to my knowledge no direct way to read this new string-value, I would not be surprised of a new lua API coming soon.

Time For Experimenting!

I’ll do some testing, but it will be a high hill to climb with my near to none programming skills. I need to look into some of the telemetry libraries and try to figure out how they are built. Then I need to build a test-sensor with some test-strings. And try to figure out a way with lua to read it. There is one lua function that just might do it, the “system.getSensorByID (<sensor ID>, <sensor param>)” gives at least all the parameters from sensor that are available. First Jetimodel sensor to maybe use this new function could be MTAG, so I’ll fool around with that too. I’ll keep you all updated when there’s something new to tell for sure.

I’m not a programmer, so don’t hold your breath waiting for results. Looks like there’s a few hours of action and coffee in “RCT Lab” coming up…

RCT "Lab"

If you have any information on the new part of telemetry protocol drop me a line here!

3 thoughts on “Jeti Telemetry Protocol Updated!

  1. Thanks for the latest news about Jeri up date I am with you on having updates put some where we can all axses Jerti would sell more radio's if they helped buyer's how to set up I no lots of fellow glider pilot's how have not even up dated there radio's since buying them in fear of getting it rounge keep the good work up and thanks again for your time.
    Kind regards

  2. Hi Tero,

    great article. I was thinking about projects such as the Library for REX protocol for Arduino. AFAIK, this has not been updated. Do you know if somebody is working on a library that takes advantage of the 1.07 version?


    1. To my knowledge there is not anything going on. But I would not be surprised if it would not pop up at some point. There is still some maturing to do like lua-reading and hopefully even writing. We need that for full usability :)

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