A second serial port is set to RC input and is ignored
What ArduPilot says:
- SERIALN_PROTOCOL: duplicate RCIN not permitted
At start-up ArduPilot found more than one serial port with SERIALn_PROTOCOL 23 (RCIN). A serial receiver is read on one port only, the first with 23; the line names the port that is being ignored. The pre-arm checks say the same thing as “Multiple SERIAL ports configured for RC input”.
What to do, most likely first
A port was set to 23 while looking for the right one, and the earlier one was left.
CheckIf the receiver is wired to the port named in the message, it is the other port that has to change.
FixKeep 23 only on the port the receiver is wired to; set the other to what is really connected there, or to -1. Reboot.
Parameters to look at
| Parameter | What it is |
|---|---|
SERIAL1_PROTOCOL | Telem1 protocol selection |
SERIAL2_PROTOCOL | Telemetry 2 protocol selection |
SERIAL3_PROTOCOL | Serial 3 (GPS) protocol selection |
SERIAL4_PROTOCOL | Serial4 protocol selection |
SERIAL5_PROTOCOL | Serial5 protocol selection |
SERIAL6_PROTOCOL | Serial6 protocol selection |
Where to do it:Board & Wiring Planner
The code that sends it
SERIALN_PROTOCOL: duplicate RCIN not permitted
libraries/AP_SerialManager/AP_SerialManager.cpp AP_SerialManager::init() · Open in ArduPilot Copter-4.7.1