Help newbie: Issue with expresslrs and ardupilot

Hi all,
I am new to this ardupilot situation and i have run into some issues.
Firstly, i am using mission planner 1.3.79 and i am not able to calibrate the compass. I am using a ‘Matek F405-WTE’ flight controller (the one with the expresslrs receiver built in) and a matek ‘GNSS & compass M10-5883’. Each time i try, i move the compass around as instructed but once i get to 100%, the green bar resumes to 0% and i have to start over again and this happens continuously.
Secondly, when i try to calibrate the radio in mission planner, nothing is happening when i move the sticks on my radio. I have also noticed that in the ‘Data’ tab of mission planner, it says it has failsafed but the LED on both the Tx and Rx are solid indicating that they are bound so i’m really lost. For the radio setup, I am using an axisflying Thor TX pro with the latest version of ELRS (3.1.2) and on the receiver side, i am using the built in ELRS receiver which i have also flashed with the latest version of ELRS (3.1.2).
Any help would be much appreciated. This is the first time i am playing around with ardupilot.
Thanks again for any help :slight_smile:

Try to calibrate the compass outside with a good GPS lock. Also, is the GPS/Compass module installed into the plane with the flight controller? Because both the FC and GPS/Compass need to be moving together when you do the calibration.

Sorry, can’t offer any advice on the ELRS. But I’m sure somebody else can.

Thank you for the suggestion!!! i have not installed the FC and GPS into the aircraft yet and i had not realised that i had to move both of them together. i tried callibrating it again whilst moving them both together and it WORKED!!! thank you so much!

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I haven’t used the built in ELRS RX on the WTE, but I did hear about some issues with some ELRS receivers from Matek having temperature related issues, which you might want to look into before you fly the aircraft. I use a lot a Matek gear, so don’t get me wrong, I like their stuff, but I’m being careful with their ELRS RXs. See here (

More likely if you’re just doing bench setup though, you won’t be running into the other issues. I really like how Matek posts the “Ardupilot Mapping” tab on their products that support Ardupilot, and for this board they specifically have an extra tab for the built in ELRS RX

Hopefully the instructions in the first section of that tab get you sorted out and working. There are a few parameters you have to change from “default”.

I actually have this same flight controller but am not using the built in RX, so it’d be great to hear how it goes for you and if you find out any more helpful info on this RX. You should also look into the “yappu script” for use with ELRS and Ardupilot. I’ve seen some pretty cool things done with it on Crossfire and ELRS but have yet to try it myself.

Please show your jumper settings for Tx1/Rx1, ERx/ETx and Tx2/Rx2. and upload your parameters here.

thank you for the help. I think i may have figured out the issue. Stupidly, i was under the impression that the Matek F405-WTE could do both Mavlink and expresslrs but i now realise you must choose between either mavlink or expresslrs. I was initially confused by the wiring diagrams on matek’s website for the FC but i now understand that you have to choose between the two and i have now wired up my FC to do mavlink.
Thanks for all the help anyways!!!

Have you established a wifi connection?

Yes, sorry, I have worked out all the problems I was having. I thought I had deleted that last query once I had figured it out but it doesn’t seem to have worked. Anyways, thanks for all the help!