Re: [Paparazzi-devel] Interference in flight Umarim lite 2.0

[Joseph Muhlhausen]

Thanks martin,

I have tried running the motor with propeller on a bench. After a good run, when close to my metal door, the servos don't respond instantly to the radio and have glitches. i also noticed that when this happens, the OK radio indicator  in the GCS is half green half orange .

I connected the servos to the umarim ground but didn't notice any change in my bench test (no flight). i then grounded the motor mount and added aluminium connected to the ground around the RX - Umarim cable section touching the battery wires. This improved my bench test, I do not see any glitches and the OK button is now 90% green.

I went to fly and it went much better. In MANUAL I don't seem to have issues but I didn't go full throttle after take off, however in AUTO1, I still have glitches as the HOME mode kicks in and the plane goes down in a spiral.

Joseph

Hi Joseph,

> My plane flies great and is properly set up for AUTO1. However, during
> the last two flights I could only control the plane intermittently.  As
> soon as I would start throttle again I would lose control of the plane.
>
> On the ground everything works fine including range test.
>
> All wires are twisted but none are shielded.
>
> Grounding:
> -ESC and Umarim share the same ground from the battery supply
> -ESC's BEC seem to have common ground (measures 0 V between Umarim
> ground and BEC ground)
> -RX and Xbee get the ground from Umarim
> -Servos get +5V and ground from ESC's BEC
> -No ground on motor or motor plate
>
> I am not sure where to start, if anyone has had a similar issue and
> found a fix that would help me a lot.

sounds like a ground issue. Between the Umarim and the servos ground
line is the battery -> ESC path. If you run the engine you will have a
current in that path that creates a voltage that disturbs the servo
signals. Try connecting the servos ground directly to the Umarim.

If that helps maybe the "Large Aircraft Connection Diagram" picture in
the Wiki needs an update.

Martin