Struggling with first fixed-wing setup

I’ve installed a Matek F405-WMN flight controller and Matek M10Q-5883 GPS/compass module in a small fixed-wing aircraft I’ve flown previously without FC assistance. I’ve successfully configured 3 helis and one hexacopter with Matek H743 boards and Ardupilot, but I’m really struggling with this one:

At first all seemed normal, I calibrated the accelerometer before installing the FC in the model, then went through the compass calibration with some difficulty but eventually got it right. Then radio calibration, servo output, and flight modes. Servo outputs for the four main controls are shifted by 2 because I’m using S3, S4, S5, and S6 on the Matek board for AETR, and I’ve set S8 as the arming channel. After playing around with RCx and SERVOx reversing I got manual controls and FBWA corrective movements to work in the right directions. But at the moment I can’t get the arming switch to work, and MP display doesn’t show the arming state, though with ARMING_REQUIRE disabled I’m able to run the motor with the arming switch on or off.

Today I tried to do the Calibrate Level, but the command failed to execute, and now the MP display shows that the model is not moving correctly – up is down and right is left and the compass is about 180 degrees off – though FBWA corrective movements are still in the right direction.

The attached param file reflects the situation at the moment. Is there anything obvious in it which might cause my problems, please?

Model B initial setup.param (19.0 KB)

You could take a look at my quick start guide for Arduplane. It’s in German but can be translated quickly. I use this quick guide in workshops for completely new Arduplane users who quickly get lost in the topic at the beginning …

The important thing is to read it carefully and work through it point by point. You are also welcome to ask questions.

For your installation, it would help if you could post the start log under Data / Tab “Messages” here. From this you can usually see what is going wrong.

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Thanks Reinhard. The translated version of your link is a help – at least it goes through things step by step rather than branching off back and forth like the ‘official’ Ardupilot documentation.

I’ve never looked at the MP ‘Messages’ tab. Does it create a start log there every time I power up or try to arm? I’ll look at that next time I’m allowed in the workshop.

The log shows you the processes in Arduplane live. Just look at it and it will become clearer.

Gotcha! Thank you. That looks like it should reduce the number of silly questions I need to ask :grinning:

do you have the gps/compass unit mounted in a different-than-normal orientation? like upside down and backwards? if so, you need to adjust arduplane parameters for the orientation (cant recall what they are). However, i’d recommend mounting the gps in the normal orientation, because i’ve had problems in the past when trying different orientations. YMMV.
GPS/compass problems will prevent arming.

Thanks Andy. Everything seems to be working correctly now, and I’m just waiting for suitable weather for the first test flight. My main problem was I kept losing track of which RC and SERVO channels I needed to reverse in order to get correct movements, because my RC channels are 1, 2, 3, 4 whereas my SERVO channels are 3, 4, 5, 6… That all worked out in the end.

RC Channel 1 has nothing to do with Servo Output 1 … The Servo Output 1 … n are merely the outputs on your FC, which you can assign almost at will.

If you control Aileron with RC Channel 1, for example, you could set Aileron to 1 in the servo output, but also to 5 or 8.

The issue was I am using servo outputs 3, 4, 5, and 6 on the Matek F504 board and, when reversing servos and inputs to get the correct aileron/elevator/rudder directions for manual control and for Arduplane’s corrective stabilising movements, I kept forgetting that RC1 (for example) corresponds to SERVO3, not to SERVO1 (which is unused in my case) :frowning_face:

oh. i thought you said the servo directions were all working correctly.
well, you got it figured out - that’s what counts.
ardupilot is such an ‘acquired knowledge’.