📡 CRSF (Crossfire)
TBS's fast, low-latency digital RC link protocol, widely used in FPV racing and freestyle for its long range and quick response.
What it actually does
CRSF (Crossfire Serial Protocol) is a digital protocol that carries all channels plus telemetry over a single pair of wires between receiver and flight controller. It replaced the older one-wire-per-channel approach and cut latency significantly, which is why it became standard in FPV.
In practice
It is used by TBS Crossfire and by ExpressLRS. The practical benefits are fewer wires, higher update rates, and telemetry flowing back up the same connection with no extra hardware.
Worth knowing
CRSF needs a real UART on the flight controller and the correct port configured in firmware. Wiring it to the wrong pad is the usual cause of a receiver that powers up but never connects.