We are happy to release the third release candidate of OpenTX 2.2.0, with support for the production version of the FrSky Horus radio!

PLEASE NOTE the following important information before hastily jumping on it:

  • This is pre-release software. We’ve done our best to ensure its quality with main focus on the new Horus platform, with second priority on all Taranis versions (few changes from 2.1), then the other supported platforms but we still expect there will be issues, as is the purpose of a release candidate we need your feedback to report things we may have missed.
  • There is currently no documentation other than this page, so get yourself a good coffee to wake up, and refer to the the great communities for help e.g. openrcforums here, RCGroups and threads like this one. You can pop in our chat room where other users and/or devs may be available.
  • Check during companion install that it installs itself in the correct directory, usually you want “Companion 2.2”. A bug that will still show up on this update may cause it to install itself in “Companion 2.1”, potentially overwriting your 2.1 install.
  • Companion does not support Horus model editing, conversion or importing from another radio at this point, when radio type is set to Horus all file operations will be disabled. All models and settings need to be entered on the radio itself. HINT: open your existing models in your previous companion version and copy the settings manually, it’s not that long.
  • Companion supports reading and writing Horus firmware when the radio is powered off then connected to USB, using dfu-util and the libusb drivers installed by Zadig, exactly like for the Taranis. See the “Flashing your Taranis Radio” section in this manual. Companion can back up existing firmware (see note below in known issues) including the stock FrSky one (save as .bin), and can flash the FrSky DFU bootloader so that no other tool and/or driver swapping is needed. You might need to disable the “Check hardware compatibility” checkbox in the flashing dialog.
  • SD card contents can be found here. Download the correct archive for your radio type, extract it to the root of an empty SD card and you’ll have all needed files. Please note that all existing OpenTX sound packs won’t work due to changes in the naming strategy, so you’ll likely want to use those that are included in this archive until popular 3rd-party packs are adapted.
  • OpenTX does not touch the internal flash of production Horus radios. Its contents do not need to be backed up and are not accessible in any way when OpenTX firmware is loaded.
  • Given that companion cannot manipulate files when Horus is selected it is not possible to simulate a Horus from within companion. You can however use the “Firmware simulator 2.2” for which you will find a shortcut in your favorite app launcher. Prior to using it make sure to launch companion, select a Horus profile and configure an SD folder with the contents of the card archive found above. The Horus profile needs to be the active one for the simulator to use that SD location.
  • There is no bootloader on Horus at this point. The SD card can be accessed while the radio is powered on, providing you selected the “massstorage” firmware option.
  • If you are using a beta Horus and are not starting fresh (i.e. you keep your models and settings from a previous OpenTX nightly) you will need to reconfigure pot types on the Radio->Hardware page and recalibrate your sticks and pots.

Known issues:

  • Companion installer may try to install itself in the wrong directory, see above.
  • The progress bar in companion when reading firmware from a Horus is broken and will reach 100% at only 25% progress. Just wait, the window will close when the process is finished.
  • Companion will warn that “the file may not be a valid firmware file” when you choose a Horus firmware to flash. Just ignore it.

A rough view of the changes in OpenTX 2.2 can be found here.

Download and install Companion and use it to retrieve and transfer the latest OpenTX firmware to your radio after configuring the proper radio type.
You need to check “Use OpenTX firmware nightly builds” in companion settings to be able to download firmware, and “Use companion nightly builds” to be notified of further companion release candidate updates.

Horus production version and beta version use different hardware. Companion defaults to production hardware, for beta radios check the “pcbdev” firmware option in the profile settings.

Changes since 2.2.0 RC2

  • Fix mixer edit page on Taranis
  • Speed up Horus model selection screen
  • Calibrating the 6-position switch on Horus does not require waiting as long between positions

Download links:

OpenTX Companion 2.2.0 RC3 (N353) - Windows Installer

OpenTX Companion 2.2.0 RC3 (N353) - Linux DEB Package 64-bit


03 September 2016