Magnetic Interference AND won't level calibrate

jsouth · Jan 1, 2018

I received a used Solo 3DR from a relative. When last flown, it worked flawlessly. When we unboxed it, it showed the Magnetic Interference message at pairing, no matter where we tried it. I'm using stock everything and the Solo app. It does have the 2.4.2 update.

After reading that this could sometimes be cured by recalibrating the compass, I have tried that several times today. Twice, I was able to get the lights below the motor pods to all turn green, but it failed on finding the GPS and reverted to the Magnetic Interference message. It's about 18 degrees here, so those attempts are fairly painful outside. I resolved myself to probably having to purchase a replacement compass and came inside.

After seeing the Level Calibration in settings, I tried that on my dining table. I waited to a slow count of ten in between each step. Every time, it fails after tilting on the right side. It never even gets to the step to turn it on its nose or butt.

Does anyone have suggestions? I can easily order a compass replacement, but will that fix the Level Calibration issue? Should I try smacking the bottom of the drone and re-try the level calibration?

Any help is welcomed.

Pedals2Paddles · Jan 1, 2018

Do you have the solex or SidePilot app? Or are you familiar with using Mission Planner on a PC?

jsouth · Jan 1, 2018

I have only the Solo app and that's all I have tried. I do have a PC. What do I do when I have these apps?

jimloss · Jan 1, 2018

jsouth said:
I have only the Solo app and that's all I have tried. I do have a PC. What do I do when I have these apps?

The 3DR Solo app is no longer supported and does not display all errors that may occur on Solo.

Solex for Android devices and Sidepilot for Apple device are apps that are frequently updated and display error messages from Solo. They each cost a small amount but work much better than the original Solo app.

Mission Planner is a free application that can run on a PC. It does much more than report errors from Solo, but this is your immediate need. Available here: Installing Mission Planner — Copter documentation

Here's a quick Youtube video that shows how to connect to Solo with Mission Planner:
If you have an accelerometer problem, level calibration won't complete and/or Solo won't arm. Smacking Solo on its belly or backside might get it working, but is not likely a permanent fix. You may have to replace the Solo's PixHawk cube for a permanent fix.

jsouth · Jan 2, 2018

Thank you sincerely for the detailed help, jimloss. I'll see what I can do with Mission Planner this evening. I may have more questions later, but if I'm understanding correctly MP will help me to determine the source of the problem by reading the error codes from the Solo?

jimloss · Jan 2, 2018

jsouth said:
Thank you sincerely for the detailed help, jimloss. I'll see what I can do with Mission Planner this evening. I may have more questions later, but if I'm understanding correctly MP will help me to determine the source of the problem by reading the error codes from the Solo?

Yes
Power on controller, power on Solo with propellers off, connect laptop to the Sololink network, start Mission Planner and connect to Solo as the video showed, then try to arm Solo. MP should show the error.

jsouth · Jan 2, 2018

jimloss said:
Yes
Power on controller, power on Solo with propellers off, connect laptop to the Sololink network, start Mission Planner and connect to Solo as the video showed, then try to arm Solo. MP should show the error.

Will do! Thank you so much.

jsouth · Jan 3, 2018

I have been able to connect with Mission Planner. However, I don't know where to get the error message.

I found this under messages in the lower left:
PreArm: Check mag field
PreArm: Check mag field
(about 80 more lines of this...)
PreArm: Check mag field
PreArm: Check mag field
PX4v2 0024001D 31355113 35333436
Frame: QUAD
PX4: 5e693274 NuttX: d48fa307
APM:Copter solo-1.3.1 (7e9206cc)
PreArm: Check mag field
PreArm: Check mag field

XevetS · Jan 4, 2018

try to do a compass calibration first, then a level cal, also the led's should be white in front and red in rear

jsouth · Jan 4, 2018

Thank you for the response. I have tried compass calibration several times. It failed each time. After the LEDs turned green during the calibration, the controller briefly said Looking for GPS and then went to Magnetic Interference.

When I boot up, LEDs are white and red but the controller shows Magnetic Interference.

Pedals2Paddles · Jan 4, 2018

If you've got mission planner up and running, please do a parameter reset first following option #1 in these instructions. Note that the first screenshot is old. It's not a checkbox anymore. It's a dropdown called layout. Change it to advanced. After you hit the reset to defaults button and confirm, you'll hear some beeping as the pixhawk reboots. Once it comes back on, the controller will reconnect on it's own. This will clear out any of the old calibrations you may or may not have done.

Now, you will need to redo all your calibrations. You can follow these instructions on this matter from the Open Solo instructions, since the process is the same even for the a bone stock solo. Please follow these directions completely and specifically to ensure you're doing it correctly. Forget what anyone else has told you do to or what you read somewhere on the internet. Do it as described here.

Once you've done the calibrations as instructed, the magnetic and level issues should be gone. Please remember to do all the other things like setting your preferences and such in the apps. Test fly. Etc.

If you still get mag and level errors after this, then you almost certainly have a hardware defect.

jsouth · Jan 4, 2018

Thank you. I'll try that. I do have a new compass coming Saturday. But I'll have time to do all the other instructions before that.

yt lee · Jan 6, 2018

Just in case, remove any metal objects away from solo, including coins and cell phone in your pockets and belt buck if it is metal. Don't put your solo on concrete floor when you do the calibration.

jsouth · Jan 13, 2018

Here's the latest. First, THANK YOU to all who have offered assistance.

The new (used) compass leg arrived and I replaced it. The Magnetic Interference error is gone.

I successfully did a parameter reset using Mission Planner and the excellent instructions from Pedals2Paddles. Then the Solo completed a level calibration for the first time since I acquired it. So far, so good.

However, after probably 12 attempts, it will not successfully complete the compass calibration. The LEDs on the drone do turn green, but it never locks to the GPS. We tried two different open areas, and rotated the drone through every axis. When it fails, a Compass Calibration error is showing on the controller.

Based on previous comments, it seems there may well be a hardware error. Is a replacement Pixhawk likely the answer? I don't want to randomly replace parts, especially if there is a way to narrow down the wonky part.

The drone is now on its way to California with my stepson, who will likely chime in after this. I had hoped to get it working while he was here.