I damaged my APM 2.0 in a crash. The unit appears to operate fine but the GPS antenna came off. 3D Robotics does not do repair's and recommended removing or cutting the trace on it. I do not know how to do ether of toughs. I am looking to the community for help in how to do the repair's or finding someone to do it for me.
Where are you located?
It might be more feasible to add an external GPS instead of repairing that one
The same happened to me after an heavy impact.
I managed to fix so that it was able to function again, but the rest of the card was so smashed that I didn't dare fly with it again.
Anywho, here is how i fixed mine:
1. Put som soldering tin on, the center connector (the antenna connector)
2. HInge the GPS antenna on the two horizontal holes (bottom of gps in the picture, in the gold part) on the GPS-base.
3. Have a friend help you to hold the GPS antenna in a 45 degree angle
4. Heat up the soldering tin, count down so that the moment you pull the iron out your buddy lowers the gps-antenna onto the melted tin. And hence reconnecting the whole thing.
5. The thing is now very fragile so i used a gluegun to fix and support the antenna by gluing all the way around.
(I have also done this with my current board as it serves as a good support structure in case of a new crash)
6. Voila, you now have your GPS back :)
Thank you I will have a go at that. I am not a big fan at trying to take the GPS off or removing the trace wiring but if worse case i will use external GPS. The APM function just fine but no GPS. Thanks for all your help
I've experienced this too.
For APM 1 there was wooden box "Ardupilot Mega Case" designed by Peter Koppendorfer that was great at protecting the APM from crash impact.
When testing hardware I use a KK board ($20) and then when the most of the kinks are worked out I switch over to an APM ($200). Surprises still do come up and the detachment of GPS antenna on the APM2 shield was my first (surprise for APM 2).
The solder repair proposed by Anders Hansen looks promising. External GPS is another work around.
The fix you are doing there is very suboptimal as the long wires will mess up the characteristics of the antenna. This is espescially important on high frequency applications such as GPS.
One thing I was thinking about if I hadn't been able to fix it my way was to buy some conductive ink (like the putty you fix the heating threads in the rear window of your car). Dab that in the middle and again fix with glue around the edges..
(Btw: Try to test the APM2 just by powering it from usb, and have it outside for a GPS fix Wait for at least 10 minutes. Kinda strange since you get lock on 4 satellites)
When has 3DR stop doing repairs. They fix a few of my stuff that was not working really cheap. However, wait time was long.
you are right about the messing with characteristics I get a 3D GPS lock and 8 sats but looks like about 50m off location accuracy is off. I will look into the conductive ink do you think it would help if i used shielded wiring that may help or is the wiring acting like a db gain on antenna. I know nothing about GPS antenna only VHF antenna systems.
Thanks for all your help
It is the same theory which implies to the GPS antenna as for VHF. The only difference is the frequency, GPS is ~1,5 GHz, compared to 30-300 MHz in VHF systems. And when one enters the realm of GHz communication things realy start to get tricky, as the margins is much smaller. So I think the shielded cables wont do you that much good anyway.
But it is strange since you get a lock the antenna should be ok enough really. Have you checked the LAT LON against another GPS (ie your smartphone). It might be that the maps are 50m off, not your GPS ;)
Good info I will check with hand held gps did not think of that.
Sorry for the extremely late answer. Didn't notice that you had posted again.
To put it simple the closer you are to the original design the better the GPS performance;)
One thing you can do to check for noise and other performance issues is to analyze a know path, ie fly in a straight line or a square. Dump the log into your computer and look at the path recorded by the gps. As long as there is no large discrepancies you are good to go.