Problem: PreArm: High GPS HDOP

ArduCopter Copter 3.2
1

This is a new build APM 2.6, Hexacopter, with Arducopter 3.2 software. GPS is a uBlox NEO-M6.

The problem; It is proving very difficult to get past the “PreArm: High GPS HDOP” warning - even though MP displays a solid 3D fix with 7 satellites (HDOP 2.37 or worse).

I am reluctant to change the default GPS_HDOP_GOOD parameter from the default 200 as that is not really fixing the issue, and an HDOP of more than 2 is not generally advised.

Occasionally the problem can be overcome by repeatedly powering the Hex off and then on again. But this is a hit and miss affair, and not reliable.

I have never experienced this before with my APM builds. We had the same issue with a parallel build of a quadcopter. My other GPS equipped multi-rotors are not presenting this problem.

NB: As a temporary work around I have increased GPS_HDOP_GOOD parameter to 300 and am able to arm the hexcopter.

2

Could be a bad GPS unit ? some sort of shielding ,or interferences sensitivity ? - can you swap your GPS unit with prooved one ?

3

Have you you tried raising the GPS on a mast?

[quote=“Hands0n”]This is a new build APM 2.6, Hexacopter, with Arducopter 3.2 software. GPS is a uBlox NEO-M6.

The problem; It is proving very difficult to get past the “PreArm: High GPS HDOP” warning - even though MP displays a solid 3D fix with 7 satellites (HDOP 2.37 or worse).

I am reluctant to change the default GPS_HDOP_GOOD parameter from the default 200 as that is not really fixing the issue, and an HDOP of more than 2 is not generally advised.

Occasionally the problem can be overcome by repeatedly powering the Hex off and then on again. But this is a hit and miss affair, and not reliable.

I have never experienced this before with my APM builds. We had the same issue with a parallel build of a quadcopter. My other GPS equipped multi-rotors are not presenting this problem.

NB: As a temporary work around I have increased GPS_HDOP_GOOD parameter to 300 and am able to arm the hexcopter.[/quote]