Wednesday, 8 July 2015

OpenTx 2.1 - preview

Development of OpenTx continues, and over the last couple of days I've been checking out some pre-release builds of version 2.1.0. This is the version which will ship with the forthcoming FrSky X9E.

Version 2.1 contains new features and enhancements including a major rework of telemetry. It also uses a new EEPROM format.

In this post, I'll do a quick preview concentrating on items of interest to sailplane pilots. Note that the official change log has not been published, but a combination of digging around on Github and my own testing is sure to cover most of the new features.

Interface improvements

Faster loading/saving

One of the few really annoying quirks of version 2.0 was the delay in displaying the model selection list. The delay varied depending on the complexity of the current model, and with my F3F setup it could take up to around 5 seconds for the model list to show. Well I'm glad to say that this is much improved in 2.1.0 - in fact the display is almost instantaneous. A small tweak, but it finally makes navigation a fluid experience.

Category picklists

Another niggle with previous versions was the amount of button pressing needed to select mixer sources etc. The good news is that it's much easier in 2.1.

You can still do it like before, by pressing [ENTER], and cycling through a long list of options. However a much quicker way is to press [ENTER long] - up pops a new 'category picker'. Choose a category and voila, it puts you straight into the first item in that category. This can save lots of clicks, in fact I manually inputted an entire F3F setup containing 50 mixers, something which I would never have contemplated with previous versions.

Source category picklist

Weight/offset bar 

If you have difficulty grappling with mixer weights and offsets, then you'll love this - a dynamically updated graphic showing the output range:

Output range shown graphically

Named switches

Switches can be identified by meaningful 3-character names instead of the default SA, SB etc. This is useful if you consistently use a particular switch or knob for a specific purpose. The names are global, i.e. apply to all models in your EEPROM.

Switches can be assigned names

Print screen

Pressing [ENTER] + [EXIT] will create a screen shot which is saved to the BMP folder on the SD card. Useful for recording telemetry screens etc.


There are a couple of useful enhancements here:
  • The failsafe mode ('preset' or 'hold') can be defined individually per channel.
  • A warning popup is displayed if you select a model which does not have failsafe set. A great little detail.

Global Functions

You can now define 'global' functions, which are available to all the models in your EEPROM. This can be useful if you find yourself creating the same functions repeatedly in different models. For example you may wish all your models to have a switch to operate the backlight.

Global functions can be disabled via the Model Setup menu.

Global functions work across all models in the active EEPROM

Companion enhancements

  • GVARs are displayed in simulator mode
  • Curves have a copy/paste facility

Copy/Paste curve


Telemetry has undergone a major rework. Unfortunately I'm not the one to ask since I use just the built in voltage and RSSI telemetry provided with the X-series receivers. Suffice to say that sensors can be added in a generic way, either by typing in the sensor ID manually or using a 'discovery' mode whereby the transmitter detects sensors connected and powered up through the receiver.

One change affecting users of X- series receivers is that in order to display the rx voltage telemetry, you have to go through the 'discovery' process with the rx powered up (though this only needs to be done once). On the plus side, you no longer have to enter any special settings for the A1 output.

Migrating EEPROM data

Companion 2.1 had no problem translating eepe's from OpenTx v. 2.0.x.

However it had some difficulties with .eepe files created in the original version of OpenTx (some channel numbers were translated incorrectly). I was able to get round this by doing the translation in two stages: first from 215 to 216 format by open/saving in Companion 2.0.x, then from 216 to 217 using Companion 2.1.

If you're upgrading from an early Taranis, I'd recommend this two-step conversion as the devs clearly and quite reasonably spent more time testing the incremental translations.

For a fuller discussion, see later blog post.


For the record, my beta testing consisted of the following:
  1. Convert old-format EEPROM
  2. Check that my F3F setup (format 216, 1388 bytes) translated correctly, and that channel outputs were correct
  3. Program F3F setup from scratch, directly on the transmitter
Although I have not test flown 2.1 yet, the latest builds appear stable.


Version 2.1 has several useful enhancements which gives the world's most flexible RC operating system a more polished feel. Those who tend to program their transmitter in the field will enjoy a more fluid experience, and telemetry users will benefit from a unified interface for registering sensors and configuring the display.

The developers have been burning the midnight oil to iron out the last remaining reported issues, and the latest builds appear to be pretty stable. As for backwards compatibility, I can confirm that my F3F setup performs on the bench just as it did with 2.0

All in all, version 2.1 represents a most worthwhile upgrade - the developers have done another excellent job and it'll be fascinating to see how they continue to develop OpenTx in the coming months.


OpenTx Clinic for pro setups, tips and tricks


Tilman Baumann said...

Thanks for this great summary. Those are some really worth while improvements.

Andrew Duncan said...

Thanks for your efforts Mike. Now I know how to set failsafe on individual channels, been scratching my head over that one. The list picker was also unknown to me, that will save lots of scrolling.

Andre said...

"The original proposal allowed global functions to be selectively disabled on a per-model basis but this was not implemented in the builds that I tested."

It's there! :)

RC Soar said...

Doh! Will amend the text - and thanks for the great work, OpenTx rocks :)

Igor Pongrac said...

I am completely new in the world of Taranis.
I bought X9E, and I'm flying F5J models.
I use Open TX 2.1.9, because he supports X9E.
Is it possible to use Esoar or Esoar plus?

Is there a better solution for F5J models with X9E?

Thank you very much


RC Soar said...

Yes, E-Soar and E-Soar Plus both support the X9E. The key difference is the motor control - on/off with E-Soar and fully variable with the Plus. Please see the specs to see which one is more suitable for your competition requirements.