Spektrum SRXL2 receiver. No Radio calibration (resolved). No servo response after radio calibration

ArduPlane VTOL Plane
1

Hello
Problem: unable to perform radio calibration
Plane: Heewing T1 Ranger vtol
FC: Matek F405 vtol
Receiver: Spektrum SRXL2 DSMX Receiver with Connector Installed, SPM4650C
Radio: Spektrum DX7
Confirmed receiver wiring to the FC is good.
Flashed latest ardupilot build multiple times with INAV
Calibrated Accel multiple times
Calibrated compass multiple times
Binded receiver and radio multiple times

Still no green bars during radio calibration.

Has this happened with anyone else?

2

SRXL2 is a half-duplex protocol and thus the signal wire needs to be connected to TX on the UART - have you done this?

3

Hello
Heewing_Ranger_rev0.param (19.1 KB)

Yes I have it connected to TX2 per the Matek documentation. I’ve also set all of the SERIAL6 parameters per Matek and Ardupilot documentation. I’ve attached my parameter file.

This is the schematic I’m using for the FC
http://www.mateksys.com/?portfolio=f405-vtol#tab-id-4

Thank you for helping.

4

Set SERIAL5_PROTOCOL to 0

5

Hello. I tried setting SERIAL5_PROTOCOL to 0, but that did not resolve the situation. I then set it to -1. Subsequently I was able to calibrate the radio. Thank you.

However, now the issue I’m having is that even with radio input, the servo motors are not responding. I had some issues with arming/disarming, but even after arming it, there’s still no movement of the servos.

Has anyone experienced that?

Attached is my current parameters file.

Thank you

Heewing_Ranger_rev1.param (22.2 KB)

6

Posting here for posterity - The Ardupilot docs for the FX405 board are technically correct, however confusing.

tldr; The Port labeled “UART 2” on the FC is not actually UART 2, it’s something else. To have the Heewing Ranger T1 VTOL work with an SRXL2 you must enter all the parameters that are listed in the docs, BUT:
1 - Use the Satellite SRXL2 4 pin port on the receiver (not the one next to the channel out put pins)
2 - Plug the TX pin in the port labeld RC-IN on the FC.

Literally had to hook everything up to the ocilloscope to realize that the port labeled UART2 is NOT serial6. Serial6 is the RC-IN port.

Hope this helps!