Issues connecting via SERIAL

MAVSDK
1

Hello,

I’m trying to use the example takeoff and land from core SDK, connecting via serial with ardupilot but i’m getting some inicial errors and can only see telemetry data and i can’t arm.
I’ve tried to print telemetry health and it shows that gyro and accelerometer calibration aren’t ok, that’s why i can’t get it armed and fly.
But when i connect to QGroundControl i can arm and fly with no problems. :confused:

I’ve done the integration of ardupilot with Marvelmind’s beacons to get fake GPS position.
I think that I’ll need to migrate to PX4. Has anyone done this integration with PX4 flight stack?

Thanks in advance,
Vinha

2

Unfortunately the Dronecode SDK is not tested against ArduPilot, so it’s probably not fully compatible. Pull requests for potential fixes would be welcome.

3

Well, i changed the flight stack to PX4 to avoid this errors.
But the first thing I noticed is that PX4 don’t acept NMEA GPS type so that i can’t use that with marvelmind.
Am i right?

4

I don’t know. You could try. There is an ashtech driver that might be similar: https://github.com/PX4/GpsDrivers/blob/2a4865adc3808687d6c6f550f497a02eb920c382/src/ashtech.cpp

@bkueng any chance we have NMEA?

5

Yes the ashtech driver is NMEA with some proprietary flavor. So it should not be too hard to get it to work.

6

As a note, marvelmind has two serial protocols: native and nmea (limited message set though). The ArduPilot driver uses the native protocol and fuses into the ekf as a beacon, not a fake gps. If the OP has set this up for ArduPilot he’ll need to reconfigure to nmea for px4, and turn off some gps checks (num satellites for instance).

7

Well, i managed to get it working with marvelmind as @auturgy said. I disabled num of satellites and now I’ve got 3D lock and in QGroundControl it shows where it is supposed to be.
The only issue I got is the altitude. I changed the EKF2_HGT_MODE to 1 to use GPS, but the altitude is very unstable. Checking in the marvelmind’s dashboard it looks stable and I have really good 3D position (very stable).
Will the drone be capable of fly with marvelmind’s information?

8

UPDATE
I got 3d lock and in QGroundControl the drone was in the position that I defined in Marvelmind. But then I noticed that when I move the drone around, the position was the same… :confused:
With this, I decided to include the driver that @JulianOes and @bkueng mencioned earlier in PX4 build, flashed, and now I can’t get any fix gps.
Am I doing something wrong?
Thanks in advance