Straightened it out and now the FC sees it! Thanks for all your help…it was quite the lesson in connectivity.
Nice you found the problem! To reiterate, the default parameters will find a connected compass if all else is good.
Well, I had changed the Compass and GPS parameters so many times I had forgotten what was default, thus the question. Seems I must have them back to normal.
Sorry to be back again, but after all that time connecting the compass, now I can’t get it to calibrate no matter what I do. I selected open area, established 15 satellites, and did the six position dance with the USB attached, and it would not complete, just kept restarting.
Then I tried the Large Vehicle calibration, rebooted, and now I get AHRS: EKF3 Yaw Inconsistent by 175 degrees. Cannot arm.
I’m also getting a message “Failed to create log directory /APM/LOGS
The calibration dance can be frustrating. If possible, I try to do mine with the quad powered from the battery and using telemetry links (same configuration as it would be when it’s flying).
On the odd occasion I’ve had quads that Mission Planner would never calibrate, but I was able to get them calibrated using QGC. I can’t explain the difference but it’s worked more than once.
I only worry about getting the compass calibration “good enough” to fly it initially, and then I use MagFit from a flight log later to get really good one.
Allister, how do you calibrate with telemetry? I read the wiki and watched the video on using a switch on my radio to calibrate, but I couldn’t tell if it was working, as my FC didn’t beep as it was shown to in the video.
Do you have telemetry on your craft back to the ground station? Nothing to do with switches its a wireless connection rather than a USB cable. Sik radios, Wifi, Bluetooth…
I have Wifi from the Speedybee FC, which sometimes works (not very reliable IMO), and I have a Sik telemetry radio that I could install.
For my personal builds my current go-to is Mavlink over ELRS. But if you’ve got good SiK radios those will work well.
I use ELRS, but I have not ventured into using it for telemetry yet. Maybe worthwhile in the long run. For the Sik, I’ll need to make a new cable to fit the Speedybee FC.
So, I’m assuming what you and Dave are describing is using telemetry to connect the FC with MP so that you can calibrate the compass without the USB tether?
I think tomorrow I’ll take your idea to calibrate using QGroundControl, and see if I have better luck.
Any idea why I’m getting the logging error? Bad SD card?
Have a look at the suggestions here:
It might help with the compass calibration as well.
Thank you for pointing this out. I was able to set up wireless communication between the FC and MP (as well as QGC), and I tried compass cal again, but no luck. I’ll look into the board memory next.
Update: I think I’m getting closer. I made some parameter changes regarding flash memory and logging, I ensured my FC orientation was set with AHRS Orientation, I redid the Accelerometer calibration, and finally moved my compass from the fuselage out onto the wing.
After all this, and using wireless telemetry, the MP Compass calibration worked! Yeah! I rebooted as required, and now the only Pre-arm message I get is the “EKF3 Yaw Inconsistent by X degrees”, and it persists for at least 15 min (when I gave up).
I understand this likely represents inconsistency between the gyro and the compass, but I don’t know how to solve it. I re-did the compass calibration, but that did not help.
I’m assuming the compass and the FC are mounted and aren’t moving relative to one another. ie: you did the calibration with everything installed as it would be for flight. I will sometimes get those errors when connected by USB, or on the work bench with all the electrical noise from all the other gadgets that are about.
Share when you’re seeing the pre-arm message? Is it outside in a flight ready condition, or on the bench? Or somewhere in between.
Outside, in open area, flight ready (battery connected), viewing messages wirelessly on MP and on radio (Yaapu telemetry).
Also tried a different GPS/Compass, with same result.
So it’s the end of the third day trying to get this compass working on this FC, and I’m thinking it’s taken up too much of your time and mine. For a plane that I’ll fly mostly in Stabilized mode and LOS, it’s just not worth beating my head against a wall.
So if I turn Compass_Enable = 0, the EKF3 should fall back to using GPS, correct? Should I set it up to use GSF? Is that better? Will I get any PreArm warning that prevent me from arming?
Fly it using GPS only and do some figure 8s. Compass data will still be logged, and you can calibrate it using MagFit and enable as desired thereafter.
Excellent idea. Thanks! So to be clear, even if I disable the compass, the compass data will still be in the log file?