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no gps lock on typhoon H

Discussed yet. The GPS position should be at least roughly the same as calculated by the accelerometer position.
True, but no one ever said that the problem of the lack of spinning of the motors with GPS deactivated could be caused by accelerometers.
I've always seen the answer that the cause is a malfunctioning FC board.
 
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The better answer is this one. Near way this cause can be a few more malfunctions which can drop the bird.

Masters here do some differentiation between questionable, almost dead, totaly dead and so on FC's.
For the ordinary users classification should be GO and NO GO.

The real problem is that callibration has incremental or decremental behaviour and schifts are quite small. So, your trick will work only if the cause is a long time after the last calibration.
 
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...today I discovered something that I think is important, .......
To me, this is like finding gold others have overlooked.
It will not be the fix for many of the failures, but it will be the fix for those to which it applies. It is also something that is easily performed at no expense. It can be easily used as an early attempt at correcting a GPS acquisition issue, and simply move on to more common errors if it does not help.
It may have been discussed before, but I don't remember it. At least not in a manner that made it stand out as the piece of gold it can be to the right situation.
Good work.
 
I tried this and it didn't make a difference, still stuck in acquiring, it was worth a shot.
I did notice the alt read between -3.8 and 4.0m is there a way to manually add an offset so it doesn't think its below the surface?

On a related note, I believe there is a heater on the FC board and I'm wondering if anyone has checked the failed FC boards to see if the heater was still functioning?, if it is not then this would cause issues, but this sounds too simple of an explanation?
 
Has your drone been unused for long time?
Have you checked on the GUI if yaw value is deviating and/or Z axis of accelerometer value is under 1000?
Are you able to start motors with gps disabled?
I don't think the altitude read is so important, otherwise who lives in areas under the sea level could never fly...and the same if you are over an hill or mountain, the altitude value should be related to the takeoff point, and reset itself to zero when you start the motors, it was so on drones of other brands I had, I think it's the same for Yuneec too.
Last year I replaced the gps battery 'cause it was totally drained, I got faster lock, i suggest you to check the voltage of that battery. Mine had a value under 2 volts, nominal is 3V.
The reality is that many users have had this problems of the acquisition of satellites in all parts of the world, so a construction defect or the use of low quality components in the flight control board is plausible, which seems to be the main cause of the issue and happens normally when circuits are not powered for months~years.
I believe the only solution in your case is to replace the flight control board.
 
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I did notice the alt read between -3.8 and 4.0m is there a way to manually add an offset so it doesn't think its below the surface?
There is no way to add an offset and it would not make sense because the altitude shown here is the result of different sensor values from IMU and baro. Usually with acceleromter calibration this will be corrected but still there is temperaure drift depending on temp compensation at barometer chip and possibly IMU heater.

On a related note, I believe there is a heater on the FC board and I'm wondering if anyone has checked the failed FC boards to see if the heater was still functioning?
With the new GUI that we have now, we can see the IMU temperature. It should increase slowly during initialization. But if the bias of the accelerometer is too high, nothing will help, heater or not and accelerometer calibrated or not. But I still believe that accelerometer calibration can prevent accelerometer problem when done before the bias went out of control.

Just for test I have here an IMU with only ~650mG on Z-axis of the accelerometer. In this case nothing will help. The AHRS subsystem flag (Attitude Heading Reference System) is not set and the FC raises following error message: "WARNING Diagnosis: AHRS Not Ready". Also the EKF status is zero. With other words the drone is unable to determine its attitude in the X-Y-Z orientation. and is not able to fly.

AHRS_EKF_Status.png

New GUI gves deeper insight now.
 
There is no way to add an offset and it would not make sense because the altitude shown here is the result of different sensor values from IMU and baro. Usually with acceleromter calibration this will be corrected but still there is temperaure drift depending on temp compensation at barometer chip and possibly IMU heater.


With the new GUI that we have now, we can see the IMU temperature. It should increase slowly during initialization. But if the bias of the accelerometer is too high, nothing will help, heater or not and accelerometer calibrated or not. But I still believe that accelerometer calibration can prevent accelerometer problem when done before the bias went out of control.

Just for test I have here an IMU with only ~650mG on Z-axis of the accelerometer. In this case nothing will help. The AHRS subsystem flag (Attitude Heading Reference System) is not set and the FC raises following error message: "WARNING Diagnosis: AHRS Not Ready". Also the EKF status is zero. With other words the drone is unable to determine its attitude in the X-Y-Z orientation. and is not able to fly.

View attachment 31632

New GUI gves deeper insight now.
I will have to try the new gui,, I have tried the older version of the gui in the past and the reading was way off and from your previous document pointed to the need to replace the FC. This is a backup drone as I have one that does fly, but getting the backup to be flight ready would be nice, just not really ready to gamble on purchasing another FC.

I mentioned he heater because as I was draining a battery after a flight the good drone felt slightly warm, so I moved the battery over to the bad drone and let it sit powered for a while and it didn't seem as warm, but it could have been my imagination. I will try taking pics with a thermal camera just for curiosity and compare.

@Pier2162

I purchased two used drones both I believe were stored un-powered for some time, not sure the exact duration, but I would guess at least a year (or more), one seems to work fine, the other has the FC issue. As I mention above it would be nice to get it back to flight ready, but not critical, I only fly the good drone once a month or so, so I'm not an avid user.
 
Here is the gui output for reference, yeah I see many of the same things, so the FC is still the issue.
Nice work btw on the gui
 

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Yeah, that seems to be the prognosis. At this point it will be used as spare parts if I ever need them. I'm located in Sanjose. I played with the idea of purchasing another FC, but it didn't seem worth it.
 

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