Matek H743 / H743 Slim: ELRS CRSF works in INAV but no RC input in ArduPilot

General
1

Request for help with radio calibration in ArduPilot

I have two drones: one with a Matek H743 flight controller and another with a Matek H743 Slim.

On both drones, the sticks worked correctly in INAV.

I changed one of them to ArduPilot, and since then the flight controller does not detect RC input.

The ArduPilot firmware I flashed was downloaded from the ArduPilot website and flashed using STM32CubeProgrammer, because Mission Planner did not detect the board in DFU mode.

The file I used was:

ArduCopter / with_bl.hex

I tried the usual settings:

SERIALx_PROTOCOL = 23 // CRSF

SERIALx_OPTIONS = 0

RC_PROTOCOLS = 1 and also 512

RC_OPTIONS = 8704 and also 8192

The transmitter is a RadioMaster using ExpressLRS / CRSF.

The transmitter is bound to the receiver, and the receiver LED is solid green after connection.

In Mission Planner, when I open Radio Calibration, the bars briefly flash green, but then become grey/dark and the sticks do not move.

I flashed the controller back to INAV, and the sticks worked correctly again in calibration.

Then I flashed it back to ArduPilot, and again the controller does not see RC input.

So it seems that:

the transmitter is OK,

the receiver is OK,

the transmitter is connected to the receiver,

the wiring likely works because it works in INAV,

but ArduPilot does not receive RC input from the receiver.

I would appreciate any help or suggestions.

2

Try BRD_ALT_CONFIG,1

3

Hi are you 100% sure you set the correct serial port SERIALz_PROTOCOL to 23?

Note ArduPilot nominally doesn’t match Serial ordering to UART numbers. That gets a lot of new comers to ArduPilot from BF or iNav.

Would you post your parameters?

Tell me which UART you have your RC RX plugged into?

Note the common TX6/RX6 for RC RX is SERIAL7 in ArduPilot.

4

Oh and i highly recommend using the “bdshot” firmware for copters which is not needed in iNav or BF.

You are likely expecting that capability in copter.

That means SERIAL7 acts normally without the BRD_ALT_CONFIG 1 required of the normal firmware

5

Sorry for all the info. … Mission Planner cannot flash directly from DFU like iNav or BF.

Currently you must download the developer tool STM32 Cube to first place the bootloader.

6

Solved: On the Matek H743-SLIM V3, the RX6/TX6 pads correspond to Serial7, not Serial6 as the labeling might suggest. If your receiver is wired to those pads, make sure to configure Serial7 (protocol, baud rate, etc.) in Mission Planner — not Serial6 — for it to be recognized correctly.

8

Awesome!

Please post all issues you have as a new comer to ArduPilot from iNav.

It will help inform some current efforts.