PX4, ELRS no sticks, no switch

PX4 Autopilot
1

Hi community,

just got an ARK FPV board. I’d like to use ELRS. But I am stucked and lost.

The PX4 version is:

ver all
HW arch: ARK_FPV
HW type: ARKFPV
HW FMUM ID: 0x000
HW BASE ID: 0x000
PX4 git-hash: 1778692ca29531ee12c4635fd913caa3288d2bfa
PX4 version: 1.16.0 40 (17825856)
OS: NuttX
OS version: Release 11.0.0 (184549631)
OS git-hash: e61fdd019de6ee7685c071760a965961c5ef5227
Build datetime: Dec  4 2024 13:53:17
Build uri: localhost
Build variant: default
Toolchain: GNU GCC, 10.2.1 20201103 (release)
PX4GUID: 0006000000003430363730335109002a001c
MCU: STM32H7[4|5]xxx, rev. V
nsh>

The board configuration seems to include crsf

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RM TX and RX have same ELRS latest FW (3.5.2).
RM TX and RX are bound and COM seems ok.
Qground Control, CRSF is enabled and set to RC (USART6, tty5)

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HW: connected to USART6; RX-TX crossed out (tried it also visa versa)

ERLS TX ARM Switch CH5 set to SA (seems to work)

Tried to diffferent ELRS receiver.

Checked that all set to CRSF protocol

Result

  • RC calibration does not show any stick or switch movement, but doesn’t tell that the RX is not connected, hence, I conclude it detects the RX (because if I disconnect it, I get a “connect RX first…”.

RC Channels:

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CRSF_RC status:

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Used following references:

Interesting In the above post is the rc_input start cmd used; but shouldn’t it be crsf_rc start instead?
and obviously also used:

Has anyone a clue what I might do wrong?

Thanks a lot!

2

Can you share your param file?

3

Sure, attached - oh it seems like that neither .params nor .txt can be uploaded.
ark_default_params_crossfire_enabled.pdf (271.0 KB)

4

Can you try main? Can you also try a param reset? Make sure you save your current param set so that you can restore it later if you need to.

5

Dear Dekejahl, may I ask you what is meant with “main”? I can try a paramter reset.

6

The PX4 main branch

7

Sure. I can compile the latest PX4 for the ARK fpv board if that is meant.

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Reset vehicle parameters: done.

No change.

8

Ok. I used instead of RC (USART6/tty5) TELE1 (in my case UART7/tty6). Same settings, same receiver and it works. It seems like that the RC port USART of the ARK FPV board does not work correctly.

9

I checked your params and it doesn’t look like there is anything else trying to use that port (mavlink for example). Perhaps the port was damaged? Did you ever hook up by accident 5V to one of the 3.3V signals? To help diagnose I would try setting up mavlink on the RC port and seeing if it works at all.

10

Dear Dakejahl, thanks a lot for your support and patience. No, I usually check my wiring 5 times, especially plus and minus and TX and RX :wink: and the lights came on correctly the first time on power up. I even tried to get soldering done neatly. And the same ELRS board worked then without problem on the TELEM 1 port.

I can try to set up mavlink on that port, good idea. I guess I have somewhere a telemetry module.

11

ARK was helpful and sent me a new board. The RC UART with ELRS works now.

There seems to be also a bug in the FW, about causing troubles when DSHOT enabled at the same time.