The plane is waiting for its receiver
What ArduPilot says:
- PreArm: Waiting for RC
The throttle failsafe is on (THR_FAILSAFE is 1) and no valid frame has come from a receiver, nor an RC override from a ground station, since power-on. The plane will not arm until it has heard its radio once.
What to do, most likely first
The transmitter is off, or the receiver is not bound to it.
CheckThe receiver's LED: solid means linked, blinking means searching.
FixSwitch the transmitter on and choose the right model; bind again if needed.
The serial port the receiver is wired to is not set up for RC input.
CheckA serial receiver (CRSF/ELRS, SBUS on a UART) needs
SERIALn_PROTOCOL23 on its port.FixSet it to 23 and reboot the flight controller.
The receiver is wired wrongly or has no power.
FixCheck TX to RX and RX to TX, and that the receiver is powered with the battery connected.
Parameters to look at
| Parameter | What it is |
|---|---|
THR_FAILSAFE | Throttle and RC Failsafe Enable |
RC_PROTOCOLS | RC protocols enabled |
SERIAL1_PROTOCOL | Telem1 protocol selection |
SERIAL2_PROTOCOL | Telemetry 2 protocol selection |
Where to do it:Board & Wiring Planner
The code that sends it
PreArm: Waiting for RC
ArduPlane/AP_Arming.cpp AP_Arming_Plane::rc_received_if_enabled_check() · Open in ArduPilot Plane-4.6.3
ArduPlane/AP_Arming_Plane.cpp AP_Arming_Plane::rc_received_if_enabled_check() · Open in ArduPilot Plane-4.7.1