As we know one of the things we human are is lazy. Combine that with the fact that most of the time on the field our transmitters are just sitting there and draining battery. If you are like me and never turn off your transmitter between use the battery might drain before day is at end. (Check out the batterylife comparison here for raw data!)

So, Lua to the rescue!

What? And how?

Jeti have added more commands to their excellent Lua-implementation in firmware 4.20 giving a new command-set of getProperty() and setProperty() where we can both read and set things like screen backlight-mode, brightness, volume- and beep-volume settings and such.

So I made a Lua-app that uses one switch-value to determine if we are using the transmitter or not. One really simple way to use the app with fully automatic function would be a telemetry-controlled switch, for example switch would be on if flight-battery voltage is over some volts or if receiver-voltage is over some voltages. I’m sure most of you already have this kind of switch configured.


Surprisingly simple what comes to functions:

  • Uses two sets of settings – When in use and when not in use.
  • Ability to set different screen brightness
  • Ability to set screen backlight-mode (Backlight timeout)
  • Ability to set total volume
  • Ability to set voice-file volume
  • Ability to set beep-code volume

After initial settings this is a true “set and forget”-application. No need to adjust between flights or anything. If you have configured your screen to be darker and temporary increase brightness application will allow that and reset it to application-set values next time you use your model and un-power it.

RCT-Comfortable is part of RC-Thoughts Jeti Tools and is available for free download from my GitHub here.

Requirements and compatibility

RCT-Comfortable is compatible with DC/DS-14/16/24 with firmware 4.20 and up. No other requirements.


In short: Copy the .lc (or .lua, the .lc is memory-optimized) file from github here to your transmitters Apps-folder, if there is a translation file copy the .jsn file to Apps/Lang-folder on your transmitter. Head on to “Applications” -> “User applications” and add the app. Guide on installation of Lua-apps available here if you need some more in-depth guide.

After that go to transmitters menu Applications -> User Applications and add the RCT-Comf to your running applications. Comfortable can be accessed from menu Applications -> RCT-Comfortable.

Configuration of Comfortable

Configuration is self-explanatory when you see the main screen. Screen is divided in sections, on top you have the switch-selection, under that settings when transmitter is in use and below that same setting for when not in use.

All values seen are read from transmitter. Define the switch and set your values how you like them. No further setup or actions are required. Here’s one example:


Well. What can I say, it’s fully automatic. So no user-input required. If you have for example a knob for your volume that still works as before. So basically so simple it can be.

Version History

  • 1.0 Initial release
  • 1.1 Added Italian translation from Fabrizio Zaini
  • 1.2 Bug fixes
  • 1.3 Added German translation by Christoph Ziegler
  • 1.4 Reading of translations changed to more efficient way


Some rules do of course apply!

  • Never use Lua to control a function that would take the model down if misbehaving!
  • Always, always test the function thoroughly!
  • If you do not know, then don’t!
  • RC-Thoughts or myself is NOT responsible for anything this application does
  • Applications are free to use (MIT-license) and linking to this page is encouraged!