OpenTX 2.1.9 is the final and most stable release of the 2.1 branch, released in late 2016. While it is considered "legacy" compared to the current 2.3.x or EdgeTX versions, it remains essential for users of older hardware or those who prefer the specific telemetry handling of the 2.1 series. 📥 Official Download Links To install OpenTX 2.1.9, you need the OpenTX Companion software. The radio firmware itself is downloaded this application based on your specific radio settings. Windows Installer OpenTX Companion 2.1.9 OpenTX Companion 2.1.9 DMG : Available via PPA or self-compile from GitHub Source 🛠️ How to Install Install Companion : Download and run the installer for your OS. Configure Profile Open Companion. Select your Radio Profile (e.g., FrSky Taranis X9D+). Check your desired Build Options (e.g., lua, sqt5font, noheli). Download Firmware button (down arrow icon). Download firmware . This fetches the file specific to your radio. Flash Radio Connect your radio to your PC in Bootloader Mode (trim switches held inward while powering on). In Companion, click Write Firmware to Radio ⚠️ Critical Compatibility Notes SD Card Content
: 2.1.9 requires a specific SD card folder structure. If you are upgrading from 2.0 or downgrading from 2.2, your sounds and telemetry screens will break. You must download the 2.1 SD card contents Telemetry Change
: 2.1 introduced a major "Telemetry Rewrite." Sensors are no longer hardcoded; you must use the "Discover New Sensors" function on the radio's telemetry page. EEPROM Conversion
: When moving from 2.0 to 2.1.9, Companion will convert your models. Always back up your models before clicking "Write" to avoid permanent data loss. 💡 Why stay on 2.1.9?
: It is a "finished" version with virtually no remaining bugs for supported hardware. Old Hardware : Ideal for the original FrSky Taranis (non-plus) Simplicity
: It lacks the complexity of the newer color-screen logic found in 2.3+. : If you are using a modern radio like the Radiomaster TX16S FrSky Taranis X9D Plus 2019
OpenTX 2.1.9 was a significant stable release in the lifecycle of the OpenTX open-source firmware for RC radio transmitters. Released on September 15, 2016, it served as the final minor update to the 2.1 branch before the community transitioned toward the 2.2 series. Overview of OpenTX 2.1.9
This version was primarily a maintenance and bug-fix release designed to improve stability and refine the telemetry system, which underwent a major overhaul in the 2.1 branch. It is still used today by hobbyists with legacy hardware who prefer the stability of this specific version over the more resource-heavy 2.2 or 2.3 releases. Key Features and Fixes
Enhanced Telemetry: Improved stability for FrSky sensors and refined data logging.
Hardware Support: Provided robust support for the FrSky Taranis X9D, X9D Plus, and X9E.
Logic Switch Refinement: Fixed minor bugs in how logical switches interacted with telemetry values.
UI Tweaks: Minor adjustments to the user interface on the transmitter for better readability. How to Download OpenTX 2.1.9
To download and install OpenTX 2.1.9, you must use the OpenTX Companion 2.1.9 software. This is the central hub for managing your radio's firmware.
Download OpenTX Companion: Visit the official OpenTX 2.1.9 release page to find the installation files for Windows, macOS, or Linux.
Configure Radio Profile: Open Companion, go to Settings > Settings..., and select your specific radio model (e.g., FrSky Taranis X9D+).
Download Firmware: Click the "Download" button (downward arrow icon) in the side menu. Companion will check the servers and download the correct .bin file specifically compiled for your radio's hardware and your selected options (like "lua" or "noheli").
Flash to Radio: Connect your transmitter via USB in bootloader mode and use Companion to write the firmware to the device. Critical Considerations
Compatibility: OpenTX 2.1.9 is not compatible with newer radios like the FrSky Taranis X9 Lite, Q X7 (some versions), or any Express (ACCESS) hardware. These require OpenTX 2.3.0 or higher.
Telemetry Conversion: If you are upgrading from 2.0.x, your telemetry settings will need to be reconfigured, as 2.1 introduced a new "discovery" method for sensors.
End of Life: This version is no longer receiving active updates. For most modern use cases, it is recommended to use the latest version available (OpenTX 2.3.15) unless your specific hardware or workflow requires 2.1.9.
Are you looking to install this on a specific radio model, or are you troubleshooting a telemetry issue? opentx 2.1.9 download
The story of the OpenTX 2.1.9 download is one of legacy, technical "ghosts," and the enduring spirit of the RC community. While it was once the pinnacle of radio firmware for enthusiasts, its download process has become a legendary puzzle for those still rocking older hardware. The Peak of the 2.1 Era
Released in September 2016, version 2.1.9 was the final, "polished" stable release of the 2.1 branch. For pilots using the FrSky Taranis or the classic Turnigy 9X, this version was the gold standard—it brought stability and essential telemetry improvements that made older radios feel modern. The "Ghost" in the Installer
An interesting quirk that became a rite of passage for users was the version reporting bug. When users went to download or flash the firmware, the download dialog would often mistakenly report v2.0.9, even though the radio version page would correctly show v2.1.9 after the flash. This led to countless forum panics where pilots thought they had accidentally "downgraded" their expensive transmitters. The 9X Struggle
For the Turnigy 9X community, 2.1.9 was particularly special because it was the last "safe" version before OpenTX moved toward more resource-heavy features. However, it wasn't without drama:
The EEPROM "Error": Many users found that uploading from the OpenTX Companion would seemingly "corrupt" the EEPROM, throwing a scary warning message.
The Fix: In a classic display of community problem-solving, users discovered that while the Companion triggered the error, the radio was actually fine—it just required a manual calibration after the flash. Where to Find It Today
If you are looking to revive a classic radio, the original OpenTX 2.1.9 download page still hosts the installers for Windows, Mac, and Linux.
Windows Users: You may need the Microsoft Visual C++ 2008 Redistributable to get the Simulator to run on modern versions of Windows.
Alternative Path: Many users on older hardware eventually migrated to er9x, which some claim offers more useful features for the limited memory of original 9X radios.
2.0 / 2.1 firmware download: build specifications not working properly #7821
OpenTX 2.1.9 remains a critical stable release for many RC enthusiasts, particularly those using older hardware. This version is notable as the final stable release in the 2.1 branch and the last to support AVR-based radios like the Turnigy 9X and 9XR. Downloading OpenTX 2.1.9 Companion
To install OpenTX 2.1.9, you first need the OpenTX Companion software, which acts as the interface between your computer and your radio transmitter.
Official Downloads: You can find the installation files on the official OpenTX 2.1.9 page.
Direct Windows Link: If the website link is broken, use this verified direct download for Windows.
Other Platforms: The official page also provides installers for: Mac OS X Linux (RPM and DEB packages)
Windows XP Users: You may need the Microsoft Visual C++ 2008 Redistributable to run the simulator. Key Features and Changes
Version 2.1.9 introduced several refinements following the major shift in telemetry handling that occurred in the 2.1 branch.
New Telemetry System: Telemetry is no longer "always on." Users must now use the “Discover new sensors” command on the telemetry setup page to detect active sensors.
Legacy Support: It is the definitive version for older 8-bit radios using the ATmega128 or stock boards.
Sound Packs: This version requires a specific 2.1 sound pack structure that is different from earlier 2.0 versions. OpenTX 2
Bug Fixes: It resolved issues such as rotary encoder freezes in the companion and added support for various DSM protocols. How to Install and Flash companion 2.1.9 link not working · Issue #9029 - GitHub
pfeerick commented. pfeerick. on Dec 20, 2023. Contributor. Looks like the link is wrong on the website. The proper link is https: OpenTX 2.1 released! - Page 6 - openrcforums
As of now, OpenTX 2.1.9 is a legacy version (released around 2016). The OpenTX project has since moved to EdgeTX (the modern successor) or much newer OpenTX 2.3.x.
However, if you specifically need OpenTX 2.1.9 for an older radio (e.g., Taranis X9D, X9D+, X9E) or to maintain compatibility with old setups, direct downloads are no longer available on the official OpenTX website (they only host the latest 2.3.x).
Here is the best way to obtain OpenTX 2.1.9 safely:
You might be asking: "Why would I download 2.1.9 when 2.3 is out?"
It’s a fair question. However, OpenTX 2.1.9 remains popular for a few key reasons:
Because this is an older legacy version, you won't find it on the main "Downloads" slider on the OpenTX website. You have to dig into the archives.
1. Find the Correct Version: You can find the files directly on the official OpenTX releases page or trusted repositories.
opentx-x9d-2.1.9 (or similar depending on your radio model)..bin file.2. Download Companion 2.1: You need the specific software tool to load the firmware onto your radio.
To actually flash 2.1.9 to your radio, you need Companion 2.1.9, not the modern Companion 2.3.
Download Companion 2.1.9:
companion-windows-2.1.9.exe on GitHub Releases.companion-macosx-2.1.9.dmg (Intel only; no Apple Silicon support)..deb or .rpm packages for Ubuntu 14.04/16.04 era systems.Installation tip: Companion 2.1.9 can run alongside modern OpenTX Companion on the same computer if you install them in different directories. Use the legacy version only for flashing 2.1.9 firmware.
If you are an RC hobbyist, you know that the software running your transmitter is just as important as the hardware itself. For years, OpenTX has been the undisputed king of radio firmware, offering unparalleled flexibility.
While newer versions like 2.2 and 2.3 have since been released, version 2.1.9 holds a special place in the history of RC. It is widely considered the final, most stable iteration of the 2.1 series—a true "Gold Standard" for many pilots still flying classic setups.
Whether you are looking to update a backup radio or you are curious about this legendary firmware, here is everything you need to know about the OpenTX 2.1.9 download.
2.1.9./SOUNDS/en, /SCRIPTS, /MODELS). Download the SD Card Content for 2.1.9 from the same GitHub release page.Downloading OpenTX 2.1.9 is a time capsule trip. It is stable for what it is, but I strongly recommend upgrading to EdgeTX (the modern fork) or at least OpenTX 2.3.15 immediately after you retrieve your old data.
Have a legacy radio you are trying to revive? Drop your questions in the comments below.
Disclaimer: Flashing firmware always carries a risk. Ensure you have a backup of your models and SD card before proceeding.
OpenTX 2.1.9 Download: Essential Guide for Legacy Radio Firmware Rock Solid Stability: As the final release of the 2
OpenTX 2.1.9 is a significant milestone in the history of open-source radio firmware. While newer versions like 2.3 or the fork EdgeTX have become modern standards, version 2.1.9 remains the final stable release for several legacy AVR-based radios and is known for introducing a revolutionary telemetry system. Official OpenTX 2.1.9 Download Links
To get OpenTX 2.1.9, you must first download the OpenTX Companion 2.1.9 software for your computer. The Companion is used to configure your radio profile, download the specific firmware for your hardware, and flash it to the device. Windows Installer Mac OS X Installer Linux DEB (32-bit & 64-bit) Linux RPM (32-bit)
Note: Windows XP users may need to install the Microsoft Visual C++ 2008 Redistributable to run the simulator. Why OpenTX 2.1.9 Matters
For many users, 2.1.9 isn't just an "old" version; it is the last version to support AVR-based radios. If you are using any of the following hardware, this is likely the most advanced firmware your radio can officially run: Turnigy 9X Go to product viewer dialog for this item. (with stock board) FlySky TH9X Go to product viewer dialog for this item. Go to product viewer dialog for this item. (standard board) Go to product viewer dialog for this item. and DIY MEGA2560 Go to product viewer dialog for this item. Key Features and Changes
The 2.1 branch introduced a complete overhaul of how your radio handles data:
New Telemetry System: Version 2.1 replaced fixed telemetry with a "Discovery" system. You must now use the "Discover new sensors" menu item on your telemetry page to see active data.
Enhanced Compatibility: Improved support for various protocols, including better DSM handling and rotary encoder fixes.
Sound Pack Requirements: Because the telemetry system changed, 2.1.9 requires a different sound pack than the older 2.0.x versions. Installation Steps
Install Companion: Download and run the OpenTX Companion 2.1.9 for your OS. Configure Radio Profile
: Open Companion, go to Settings, and select your specific radio model (e.g., Taranis X9D+ Go to product viewer dialog for this item. Turnigy 9X Go to product viewer dialog for this item.
Backup Existing Data: Always use the "Backup Radio to File" feature before flashing to ensure you can revert if necessary.
Download Firmware: Click the Download icon in Companion. This sends a request to the OpenTX build servers to generate a custom .bin file for your radio's options.
Flash Radio: Connect your radio via USB (typically in bootloader mode or power-off mode depending on the hardware) and select "Write Firmware to Radio". OpenTX 2.1.9
OpenTX 2.1.9, released in late 2016, remains a pivotal version of the open-source RC transmitter firmware because it is the final stable release to support older AVR-based radios. While newer branches like 2.2 and 2.3 have since taken over for modern hardware, 2.1.9 is still the "gold standard" for legacy equipment like the Turnigy 9X and FlySky TH9X. Why OpenTX 2.1.9 Still Matters
For hobbyists using older hardware, this version is more than just a legacy download; it’s a necessity.
Legacy Support: It is the last version compatible with AVR-based radios (9X/9XR with stock boards, Gruvin9x, and DIY MEGA2560).
Telemetry Overhaul: The 2.1 branch introduced a completely new telemetry handling system compared to the older 2.0 branch, offering a more unified interface for registering sensors.
Stability: As the final release of its branch, it contains all the cumulative bug fixes and refinements developed over the life of OpenTX 2.1. OpenTX 2.1.9
OpenTX 2.1.9 represents a time when the firmware had matured into a perfect tool for the job. It stripped away the bloat and offered a pure, reliable experience for the Taranis generation.
If you are looking to restore an old radio or keep a classic setup running smoothly, the OpenTX 2.1.9 download is the perfect choice. Just remember to use the matching Companion software!
Disclaimer: Always verify you are downloading the correct firmware variant for your specific transmitter hardware. Flashing incorrect firmware can brick your device.