Compass Errors & Drifting

[Busa]

I've been a member of this forum since December. Mostly learning from others. I just purchased my second H with RealSense. It flys perfectly for about 2-3 minutes then starts to drift and occasionally does the circles. I believe the compass module is defective as I get the orange flash and sometimes the magnetic interference message. I've done the compass calibration according to the directions many times, taken off all metal stuff, no cell, etc. Makes no difference where I perform the calibration. Any ideas?

Thanks

 

[Steve Carr]

I've been a member of this forum since December. Mostly learning from others. I just purchased my second H with RealSense. It flys perfectly for about 2-3 minutes then starts to drift and occasionally does the circles. I believe the compass module is defective as I get the orange flash and sometimes the magnetic interference message. I've done the compass calibration according to the directions many times, taken off all metal stuff, no cell, etc. Makes no difference where I perform the calibration. Any ideas?

Thanks

Couple of questions.
Does it always drift in the same direction?
What altitude do you see circling and is it at the same altitude as drifting?
Is this a complete system or did you bind a new H to your other ST16?
What firmware is on the H?
Have you done an accelerometer calibration?

 

[Busa]

@ Steve
When it does the circles, they are always counterclockwise - it will not hold altitude, in fact it seems to lose altitude.
Altitude is roughly 15 feet as I was in the test flight mode. When it drifts there doesn't seem to be any correlation with altitude.
This is a completely new system.
Firmware is the latest from Yuneec. ST16:v01.00.45, AutoPilot:V1.35, Gimbal V1.25, Camera V3.2.34(A)
Yep, I perform an accelerometer calibration right after the compass calibration.

I've never seen the compass warning message before. "Keep away from magnetic interference, or do compass calibration"
Additionally, I am in angle mode with OBS Avoid disabled. I've also calibrated the ST16. Hardware monitor shows nothing abnormal.

Busa

 

[Busa]

Here is a video of the circles. I was trying to induce them by making rapid changes.

 

[Steve Carr]

Here is a video of the circles. I was trying to induce them by making rapid changes.

So it's doing a mini orbit kind of thing. Before throwing in the towel I'd try a couple of things.
Delete the flight data and create a new model, bind and then do the calibrations again. When you turn it on the first time to fly, let it sit with the motors off for about 10-13 minutes. Then take off and go up to 25-35' and let it hover. Do a slow yaw and watch for drift. Then take it for a flight but stay high. Bring it back and land without stopping on the way down. If all seems to go well try another flight.
In your video I didn't see any drift. If it does, you can try the right trim pad to see if that will stabilize it.
Let us know what you find.

 

[Mojoe35]

I had a drifting problem a day or so ago. My H would drift backwards and also from side to side, just very slowly fortunately. I think I figured it out. I went into the hidden calibration setup and when I got to the 2nd part of the tests where you move every lever, button and control stick on the ST16, I had never paid attention to the numbers for the trim pads. All I had done in the past was to just see that the RED FAIL turned to GREEN PASS. Today, I noticed the numbers were NOT at zero for the trim pads. I pressed the buttons until they all read ZERO. Now all seems very correct, though I haven't taken it out for a test flight yet. And tomorrow is supposed to be rain! My point is, remember to check what the numbers show and reset them if they are not in neutral or zero.

Happy Landings...

 

[Steve Carr]

I had a drifting problem a day or so ago. My H would drift backwards and also from side to side, just very slowly fortunately. I think I figured it out. I went into the hidden calibration setup and when I got to the 2nd part of the tests where you move every lever, button and control stick on the ST16, I had never paid attention to the numbers for the trim pads. All I had done in the past was to just see that the RED FAIL turned to GREEN PASS. Today, I noticed the numbers were NOT at zero for the trim pads. I pressed the buttons until they all read ZERO. Now all seems very correct, though I haven't taken it out for a test flight yet. And tomorrow is supposed to be rain! My point is, remember to check what the numbers show and reset them if they are not in neutral or zero....

Good find. Hope this corrects everything. Let us know how the flight goes.

 

[Mojoe35]

Good find. Hope this corrects everything. Let us know how the flight goes.

Well, the rain held off this morning for a while. I rechecked everything in the system and didn't see any problems. No constant chiming except when I push on the right hand joystick. That is normal.
I took it outside and fired up the ST16, then the H and waited till it was all fully booted. I started the motors first without props, and then shut down the motors to see if there was any chiming sound. There was none. I restarted the motors with props installed and waited a few seconds. All seemed quite normal. I increased the throttle and it rose up in the air to about 15 feet. I let it sit there and then flipped the gear switch. The gear moved slightly, but didn't retract. I flipped the switch again and then the gear went up OK. I went up higher and paused to see if there was any drifting. Nothing more than about six inches. I continued the flight making slow turns and moving forward and aft, then left and right. All appears to be in good shape. I made a soft landing and shut everything down. So apparently the calibration test were correct when I made the trim buttons all read ZERO. Then it started to RAIN AGAIN!! Have a great weekend!

 

[Steve Carr]

Well, the rain held off this morning for a while. I rechecked everything in the system and didn't see any problems. No constant chiming except when I push on the right hand joystick. That is normal.
I took it outside and fired up the ST16, then the H and waited till it was all fully booted. I started the motors first without props, and then shut down the motors to see if there was any chiming sound. There was none. I restarted the motors with props installed and waited a few seconds. All seemed quite normal. I increased the throttle and it rose up in the air to about 15 feet. I let it sit there and then flipped the gear switch. The gear moved slightly, but didn't retract. I flipped the switch again and then the gear went up OK. I went up higher and paused to see if there was any drifting. Nothing more than about six inches. I continued the flight making slow turns and moving forward and aft, then left and right. All appears to be in good shape. I made a soft landing and shut everything down. So apparently the calibration test were correct when I made the trim buttons all read ZERO. Then it started to RAIN AGAIN!! Have a great weekend!

Excellent. Sounds like you may have it back in shape.

 

[NorWiscPilot]

Looks like Mojoe35 figured it out and reminded us of some good pointers.

Question is, how is Busa doing?

Jeff

 

[Busa]

@ NorWiscPilot: Opened up a case with Yuneec and sent them my Telemetry file. They are now requesting a copy my flightlog folder.

@ Steve Carr: I'll delete the flight data and create a new model once the rain stops.

@ MoJoe35: all the trimpad numbers currently read "0"

 

[Steve Carr]

@ NorWiscPilot: Opened up a case with Yuneec and sent them my Telemetry file. They are now requesting a copy my flightlog folder.
@ Steve Carr: I'll delete the flight data and create a new model once the rain stops.
@ MoJoe35: all the trimpad numbers currently read "0"

New nature rule.........only rain at night........
Hope you see improvement. If not, Yuneec will take care of you.

 

[mcbutler]

I have started calibrating my accelorometer very precisely using a spirit level. I place coins under each corner of the landing gear to get a precise level.
It has improved position holding to an amazing degree, not even the tiniest drit..

 

[NorWiscPilot]

I have started calibrating my accelorometer very precisely using a spirit level. I place coins under each corner of the landing gear to get a precise level.
It has improved position holding to an amazing degree, not even the tiniest drit..

MC,

Interesting!

What is your measurement point or points? Top of the shell or across the gear pads/struts?

Thanks!

Jeff

 

[PatR]

I don't know if the following might be in any way applicable or helpful for the OP's issue, but here's what I experienced today and the resolution.

After letting my first H sit after coming back from Yuneec for repairs after a fly away earlier this year I finally broke it out to set up the system again and perform all the calibrations, including the transmitter calibrations in the "secret menu". Since I just moved back to California from Oregon it got to do a long power on sit to acquire the GPS almanac. So the first flight was doing pretty well but I noticed the H was drifting to the right when placed in a hover. No circle, just a constant straight line drift at about 1mph or so. This was in Angle mode, I never flew Smart and GPS was on for the flight. Correcting the drift was pretty easy by using the D pad to input a couple pad bumps of left "cruise".

After landing I checked all the channels and all indicated they were centered, leading me to believe I may have inadvertently pressed the D pad for right "cruise" at some point during the previous flight. Just in case I performed the secret menu transmitter calibrations again and launched a second flight for another systems check. This flight provided no indications of drift when the H was placed in a hover at any altitude.

In addition, something else that may be of interest, for both flights I had the boom LED's turned off since it was broad daylight. Flight times for battery level ran about 2 minutes longer for the voltage level achieved under some pretty aggressive flying. Wind was fairly light at ~5-7mph.

 

[Busa]

@ PatR: No issue with inadvertently pressing the D-pad. Both directions are centered.

@Steve Carr: I deleted all the flight data and created a new model. Then calibrated everything from scratch. Had a few issues with the camera constantly pointing off to the right and making a buzzing sound. Removed and reinstalled the camera then rebooting everything - that seems to have resolved the issue. I let the H sit for approx 10 mins. Then hovered at about 75 feet for 4 mins. No drifting or compass errors. I changed batteries and flew out over the field behind my house then returned for a low hover. Again, no issues. I will admit that it was about 30 degrees cooler than when I first posted. I've attached two pics. The first the telemetry when the H was circling. I was getting 50 compass calibration warnings that started 4 mins into the flight. The second is after I created a new model. No errors however, I have no idea why the rest of the data is reading zero.

So far, creating a new model and recalibrating seems to have resolved the issue. I'll have to wait until it gets warmer to declare it a complete success.

 

[Jester]

I've been a member of this forum since December. Mostly learning from others. I just purchased my second H with RealSense. It flys perfectly for about 2-3 minutes then starts to drift and occasionally does the circles. I believe the compass module is defective as I get the orange flash and sometimes the magnetic interference message. I've done the compass calibration according to the directions many times, taken off all metal stuff, no cell, etc. Makes no difference where I perform the calibration. Any ideas?

Thanks

Hiya Busa,
lol
I had the same thing happen with mine a few months back, after doing everything recommended to no avail. Had to send it in to Yuneec, and as you are suspecting with your, it turned out to be a bad gps/compass card. Sucks that I was without it for a month, but it solved the problem. I'd check everything else that's been said here first to avoid the down time and hopefully it's just a simple fix. Good luck.

 

[Rubik]

After resolving some issues introduced when I messed up in the "secret" menu, I finally figured out what I'd done wrong and got my ST16 back to normal. In the process of struggling, I had rerun the latest ST16 firmware update including deleting the data. Once the ST16 was working properly, I rebound the TH and ST16 and recalibrated the accelerometer and gimbal at home. The weather was cooperating, so I took it to my favorite flying site yesterday morning. I recalibrated the compass (camera/gimbal left on to flop around) facing north.

So, this was a perfect opportunity to see how long it takes the TH to be stable in flight after a major change. When I asked a Yuneec customer service rep back in March about the need to wait 12-15 minutes after update or substantial change of venue, he said that it wasn't necessary on the TH. You can fly as soon as the GPS says READY. So, that's what I did. But the bird tended to drift to the right when flying forward and to the left when flying backwards. Also, drifted fore and aft when slewing right and left. Not uncontrollable, just enough to be annoying. After flying through 1 battery and into the next, I did the same test and noticed that the drifting issue was completely gone. So, apparently, all the comments about waiting for the GPS almanac to update are correct.

 

[Typhoon Charlie]

After resolving some issues introduced when I messed up in the "secret" menu, I finally figured out what I'd done wrong and got my ST16 back to normal. In the process of struggling, I had rerun the latest ST16 firmware update including deleting the data. Once the ST16 was working properly, I rebound the TH and ST16 and recalibrated the accelerometer and gimbal at home. The weather was cooperating, so I took it to my favorite flying site yesterday morning. I recalibrated the compass (camera/gimbal left on to flop around) facing north.

So, this was a perfect opportunity to see how long it takes the TH to be stable in flight after a major change. When I asked a Yuneec customer service rep back in March about the need to wait 12-15 minutes after update or substantial change of venue, he said that it wasn't necessary on the TH. You can fly as soon as the GPS says READY. So, that's what I did. But the bird tended to drift to the right when flying forward and to the left when flying backwards. Also, drifted fore and aft when slewing right and left. Not uncontrollable, just enough to be annoying. After flying through 1 battery and into the next, I did the same test and noticed that the drifting issue was completely gone. So, apparently, all the comments about waiting for the GPS almanac to update are correct.

They have been ever since I got into GPS assisted multi rotors 6 years ago.Designing and building heavy lift crafts for movie production using APM, Pixhawk, DJI and Microcopter flight controllers. Most everything these techs say have to be taken with a grain of salt. Some of the answers I have gotten from techs are either totally wrong or way off. I don't even bother anymore.

 

[Busa]

I flew the H this morning in a 18MPH gusting wind. Temp was around 50F. H held surprisingly steady. When I reviewed the Telemetry, only 2 compass calibration errors. I just got back from flying two batteries and the H starting drifting about 9 minutes into the first flight. No wind and temp was 70F. Eight compass calibration warnings starting 9 minutes in and lasting the remainder of the flight - also got the orange blinking led. I switched batteries and took off away from my back yard and hovered over the field behind my house. Five or so minutes in, the H started to drift in all directions. At that time I observed the orange blinking led. The telemetry log shows that's when the compass calibration warnings started. The H is tough to fly when this happens as it does not want to remain steady. I also fly fixed wing and helicopters so I'm used to having to constantly correct. I immediately landed. I've attached both UAV toolbox telemetry pics.

I suspect my H has a bad compass module that starts reporting errors once it warms up. Still waiting to see what Yuneec has to say.