How to update the FrSky EthOS firmware on the X20 and X20S
FrSky's EthOS system offers most of the power and flexibility of OpenTX in a more straightforward graphical user interface. But EthOS also goes through constant upgrades as additional features are added and bugs removed. Updating EthOS on your FrSky X20 and X20S radios is relatively easy, and you can see how to do so below.
Check to see which EthOS firmware you are running. Go into Systems > Info, and it'll be the second line. You can also see your Internal Module version on this page; that is the 5th line. The Internal Module is for the RF link between the transmitter and receiver.
Download the newest EthOS firmware here: https://github.com/FrSkyRC/ETHOS-Feedback-Community/releases
Please follow this video if you don't know how to flash the newest firmware. Don't worry. It's a pretty simple process of downloading a few files and then dragging them into the correct spot on the SD cards: https://www.youtube.com/watch?v=XkVOgo5UUt4&t=384s
To update the latest Internal Module firmware, visit https://www.frsky-rc.com/tandem-x20s/ and click RF Firmware – TD Module, and download the newest version.
Drag the Internal Module firmware into the Firmware folder on the SD card, then turn your radio on. Go to Systems > File Manager > Firmware, long-press file, then choose Flash Internal Module.