Ethos Manual

Ethos is the operating system that runs on FrSky's Ethos-family radios (X20S, X20 Pro, X20 Pro AW, X18S, and others). This manual covers setting up a model from scratch, configuring the radio's system-level settings, building custom telemetry displays, and the Lua scripting environment that sits on top of all of it.

Work in progress

This manual is being rebuilt from scratch. Many sections are placeholders for now — see Contributing if you'd like to help fill them in.

Where to start

• New to Ethos? Start with Getting Started — the main screen layout and how navigation works before touching any settings.
• Setting up a new radio? See System Setup for the one-time, radio-wide settings (hardware calibration, alerts, battery).
• Programming a model? Model Setup covers mixes, outputs, flight modes, and everything else that lives per-model, and the Tutorials walk through building fixed-wing, flying wing, and helicopter models end to end.
• Building a telemetry screen? See Displays.
• Want a specific task solved quickly? Check the How-To Guides.
• Writing or installing Lua scripts/widgets? See Lua Scripts.

Radios covered

This manual is written primarily against the X20S, with radio-specific differences (X20 Pro, X20 Pro AW, X18S) called out in Radio Notes where the UI diverges.