ExpressLRS guides

These guides cover ExpressLRS (ELRS) binding, versions and firmware. Each one says which line it covers, and they're researched from the ExpressLRS docs and release notes, not our own bench tests.

Start here

• Receiver won't bind, or you're binding a new one: How to bind an ELRS receiver. Version check first, then a binding phrase or bind mode, plus an LED troubleshooting table.
• Wondering whether to update to 4.1: ExpressLRS 4 vs 3. Who should update, why STM32 hardware (R9M, ExpressLRS PP, Ghost) stays on 3.x, and what changes (arm flag on CH14 in 8ch/12ch Full Res, settings lost in the LittleFS switch).
• RadioMaster Pocket owner: the radio side is in our Pocket ELRS setup guide.

Next in this section: ELRS receivers explained, ELRS packet rates and how to update ExpressLRS firmware.

Which TX and receiver connect

Scroll the table sideways for more columns.

Sources: ExpressLRS 4.0.0 notes github.com; Betaflight 2026.6 notes betaflight.com; ExpressLRS SPI receiver docs expresslrs.org.

SPI receivers are the ones built into the flight controller on many whoops; their ELRS version comes from the Betaflight build, not from ExpressLRS Configurator.

Safety

Flashing the wrong target can leave a receiver or module unusable, so use your device's exact target. Before going from 3.x to 4.x, download hardware.json from each device's web UI and save a Betaflight diff all. After any update, check the arm switch and failsafe with the props off. Run the regulatory domain that's legal where you fly. Our how we research page explains our sources.