No GPS lock

[SuperSharpShooter]

I've just done the maiden flight of my Autoquad powered Y6, and it went well after a bit of a sketchy start. First time up it seemed quite unstable, and when I let go of the sticks it took off forwards, but after putting it down and taking off again it flew stable. I could engage alt hold which bumped up and down a little.. I will need to tune the PIDs to get it perfect.

At the moment I am unable to get a GPS lock. The blue light just flickers faintly with the occasional bright flash. The GPS is mounted above the FC with plenty of clearance, and it's been sitting out under clear sky for over 10 minutes now. I see some other people had faulty GPS antennas, so I'm wondering how to check whether mine is or not.

The connection where the GPS plugs into the board seems to be clipped in properly.

Cheers
Glenn

[LPR]

Glenn

The first time you have the GPS get a lock can take quite awhile. Just leave the Y6 outside for up to an hour and then after that you'll get a lock very quick.

Larry

[SuperSharpShooter]

Alright I'll keep trying. Thanks.

[SuperSharpShooter]

One other thing I've just noticed while it's sitting still on the lawn at the moment, is that in QGroundControl, I see the artificial horizon bumping up and down quite a bit. The magnitude isn't huge, but it's pretty much constantly bumping around. Is this a problem?

So I've just been looking around in QGC, and in the mavlink messages from the GPS, it looks like it's getting the correct lat and lon. Fix_type is 2, and satellites visible is 255. Still no blue light after ~45 mins. I do have some tall trees on one side of my place here. I wonder how much that is affecting it.

[SuperSharpShooter]

Tried giving it over an hour sitting at another location that doesn't have tall trees nearby, and still no gps lock light. I think something is not right.

[JussiH]

Pls post a photo of how the antenna is mounted. EMI from the board can cause this behavior. A groundplane between the FC and antenna is a good idea to improve reception quality.

Normally a lock should be aquired inside 30-45 seconds from cold start.

[SuperSharpShooter]

Here's how it is placed




I can make a ground plane for it tomorrow to see if that fixes it

[cm01]

I've used the autoquad shield for GPS antenna and connected the shield to ground.
After that I had a much better gps Signal.

Chris

ImageUploadedByTapatalk1363799207.370390.jpg (78.53 KiB) Viewed 8815 times

[SuperSharpShooter]

I've just taken the GPS off, and found that the outer sheath doesn't appear to be attached where it is soldered onto the antenna. The inner looks like it passes through OK. I guess that's why it wouldn't lock... Now to try and solder it up. Is this a warranty issue?

[GoFaster]

I believe the outer sheath is only connected at the U.FL connector end (AQ side). Only the center feed is connected to the GPS patch antenna. Make sure the center pin at the connector isn't mashed and that it mates securely with the socket on the AQ.

Edit: the shield SHOULD be soldered to the antenna's PCB ground.