Tutorial: How to Flash OpenTX Firmware to Radio Transmitter

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This tutorial explains how to flash OpenTX firmware to your radio. To stay up-to-date with the latest version for bug fixes and new features, it’s recommended to keep OpenTX software updated on your transmitter regularly.

The same procedure should work on most if not all the OpenTX compatible radios, including Frsky Taranis X9D, X9 Lite, QX7, X-Lite, Horus X10/X12, Jumper T12/T16/T18 and Radiomaster TX16S.

You don’t have to update OpenTX if you don’t want to. But do check firmware release note and see if there is any particular bug fixes or new features that might interest you.

Download OpenTX Companion

OpenTX Companion is the software we will be using to flash OpenTX to our radio, and to manage settings and models.

Download OpenTX companion here: http://www.open-tx.org/downloads

I am not sure what the best practice is, but I always download and install the latest version whenever I want to update OpenTX on my radios just in case.

Find the version you want (preferably the latest one).

Scroll down to the Download Links section to download and install “OpenTX Companion” to your operating system (Windows, Mac or Linux).

Make Backup First

After flashing OpenTX firmware, your model profiles should still be there, that includes their settings. You shouldn’t need to to re-bind receivers, everything should work as they were before. With that said, you should still make backup of the models, existing firmware and SD card content before flashing OpenTX, just in case something goes wrong.

To do that, first put your radio in Bootloader Mode.

For Jumper T16, T18 and Radiomaster TX16S, you need to press both horizontal trim buttons inwards while powering on the TX:

For the Frsky Taranis X9D it’s the same:

For the Taranis Q X7:

For the Frsky X-Lite, you need to hold down the trim button at the center (make sure all 4 trim buttons are pressed), then power on the TX.

 This is how bootloader mode screen looks like:

Once the radio is in bootloader mode, you can plug in a USB cable to the radio and connect it to your computer. The screen will inform you about the USB connection.

Start OpenTX Companion you just installed on your computer.

There are 3 things to backup:

• Models
• EEPROM
• Existing OpenTX firmware

To backup Models, find the icon on the left hand sidebar, that says “Read Models and Settings from the radio“. It will display your models in a new window. You can then save it as a “.otx” file on your computer. (Click on File => Save as)

To make a backup of EEPROM , find the icon on the left sidebar that says “Backup Radio to file“. It will create a “.bin” file that you can save somewhere on your computer.

Finally, to back up the existing firmware, find the icon that says “Read Firmware from Radio” in the same sidebar, and save the “.bin” file.

Alternative Way of Backing Up EEPROM and Firmware

Not officially recommended, but you could also try this if you have trouble using Companion.

When connecting the radio to computer in Bootloader mode, it will mount a new external drive and there are two files inside the drive: FIRMWARE.bin and EEPROM.bin, these are the two files we want to make a backup of.

To backup EEPROM, you can also go to Radio Settings, scroll to Hardware (V2.3) or Version (V2.2 or older), long press the Enter button, it will create a backup file of EEPROM in the EEPROM folder on your SD Card.

Compile OpenTX Firmware

We have to “compile” the firmware first by selecting the features we want to have, then we can save the firmware file and write it to the radio.

Click on the SETTINGS button on the top row (the gear icon).

Edit Settings, Radio Profile

In the Edit Settings / Radio Profile tab you need to choose the radio type you are about to flash from the list.

Select your radio from the “Radio Type” drop-down list.

Select the following build options:

• lua / luac– to be able to use LUA scripts (must have)
• noheli – to exclude helicopter config as I only fly quadcopters and wings

Optional:

• If you want to use the EU version of OpenTX, select eu. For International version, just leave it unchecked
• sqt5font – slightly better font on Taranis X9D screen (looks good on telemetry screen)
• flexr9m – if you use Frsky R9M module with Flex firmware, you have to select this option
• internalmulti – select this if you have internal mutiprotocol module (for Jumper T12 / T16 / T18 and Radiomaster TX16S)

SD Structure Path: You have backed up your SD card in the radio already right? Then just select the copy of your SD card here. This allows OpenTX companion to populate the model image selector with the images that are on the card, and do the same for audio files.

Stick Mode and Default Channel Order: I recommend using Mode 2 and AETR because this is the default in Betaflight. See this post if you don’t understand what channel map is.

For Taranis users, you can also upload your custom splash screen image on this screen. This is the logo that appears at power up, and it can only be uploaded when you flash OpenTX firmware. The required image format and size for the QX7 is monochrome BMP 128×64 pixels. For the X9D it should be 212×64 pixels.

Edit Settings, Application Settings

In Application Settings tab, you don’t really have to change anything normally.

The only setting you should know about is “Release Channel“. If you wish to flash a release candidate (RC) or unstable nightly build, you enable it there. However, I recommend flashing only stable releases, if you decide to flash unstable releases, do so at your own risk.

Download OpenTX Firmware

Press OK to close the “Edit Settings” Window, and press the Download icon from the toolbar:

In the Downloads pop up window, press “Check for updates” and you should be prompted to save the firmware file (with .bin file extension). If not, Press Download Firmware to download it.

Update SD Card Contents

Press Download SD contents button (or visit this link: https://downloads.open-tx.org/2.3/release/sdcard/) will take you to a webpage, where you can download the SD card content you need to copy to the SD card inside your radio.

You want to get the one with the same release date as the firmware you just release. If you just flashed the latest firmware, then get the latest SD Card Contents.

Back up the files currently on the SD card first to your computer, then delete everything on the SD card, and copy the new SD Card Content to it. Then copy any custom files you had previously, I usually just overwrite those folders from the backup like

• IMAGES
• SOUNDS
• MODELS

It is important to delete the old content on the SD Card before copying the new files there. Otherwise you might get a warning message on the startup screen, complaining about “the SD card content being incompatible with current OpenTX version”.

Flash OpenTX Firmware to Radio

Once you’ve complied and downloaded the firmware file, click Write Firmware To Radio button on the left side menu. Load the firmware file you saved previously, and click “Write to TX”.

Once the flashing is done, you can unplug USB cable. That’s it, you have successfully updated OpenTX on your radio.

Restoring Backup

For whatever reason you want to roll back to previous state, you can always restore the radio firmware, EEPROM and models that you backed up before flashing.

Simply use the buttons on the left hand side menu in OpenTX Companion to write those backup to the radio:

• For models: “Write Models and Settings to Radio”
• For EEPROM: “Write Backup to Radio”
• For firmware: “Write Firmware to Radio”

For EEPROM you can also do this:

• copy the backup file to the SD card
• enter to bootloader mode and choose Restore EEPROM

Flash OpenTX in DFU Mode

If for some reason you can’t turn on the radio, you can still flash it under DFU mode.

Connect the radio to computer via USB cable, your computer should detect a new device connected. Then run the ImpulseRC Driver Fixer (download) if you haven’t done it before just in case, it installs/fixes the DFU driver on your computer. Make sure you don’t have other DFU devices (such as flight controllers) connected so your computer doesn’t get confused.

Now go to the Companion menu, “Read/Write”, and select “Write Firmware to Radio”.

In the pop up window, select the firmware file, and click “flash”.

The flashing screen is a bit different than what we described previously, but the result is the same. You will get a warning saying “File has no DFU suffix”. It’s normally just ignore it.

By the way, flashing via DFU mode also updates the radio’s bootloader firmware. So if you also want to update the bootloader you can flash OpenTX this way :)

Updating OpenTX Bootloader

Your radio might work without ever updating the bootloader, and you probably won’t notice any difference. But for some radios with really old bootloader, it might cause issues in new version of OpenTX and you might have to update it, for example you could run into errors when flashing your receivers from the radio.

To update Bootloader, just flash your radio’s OpenTX firmware via DFU mode as described above. Alternatively, this is how to update OpenTX Bootloader manually.

Edit History

• April 2017 – guide created for Frsky Taranis X9D
• July 2018 – updated for OpenTX 2.2.2; added instructions for X-Lite
• Jun 2020 – updated instructions for T16, T18 and TX16S
• Jun 2021 – updated for OpenTX 2.3, added instructions on how to flash in DFU mode