Rosetta + Anker battery + on/off switch + eliminate microUSB

[exfirepro]

Hi bladeslapper,

In that case, the easiest option to improve GPS fix would simply be to put the existing GPS dongle on a short USB extender and mount it on the top end of the case between the two antennas (it fits - I have just checked). If you are worried about insulation, cover it with a bit of heat shrink or make up a 'cover' out of a bit of plastic from some scrap packaging.

Best Regards

Peter

[bladeslapper]

Yes I completely agree but no that's pretty much the best we can do. It's the same in most helis.

Actually this isn't completely true, as discussed previously on this thread, mounting the unit upside down will result in the aerials being much more vertical but may add some visual obstruction issues. I thought I would try the simple and likely worst case scenario first but I will invert it next time and see how that is.

In that case, the easiest option to improve GPS fix would simply be to put the existing GPS dongle on a short USB extender and mount it on the top end of the case between the two antennas

That would be a nice solution, and in fact if it was inverted then it could go on the other end which could be much neater if I design and print a new end cap to slide on and contain the dongle.

I'm actually surprised at how well the dongle worked with the aerial facing completely the wrong way and insulated by a battery!
I've flown again for 2 hours since and these additional logs show that it could see an average of 10 sats and no loss of GPS data for both flights.

I still might move the dongle as I'm just curious to tinker!

[bladeslapper]

An update to this mod:

As was inevitable during another lock-down, I decided I might as well move the GNSS receiver even though there seemed to be surprisingly no problem with the antennae facing completely the wrong way!
I soldered an old USB lead onto the module headers and secured it under the Pi with some carefully placed high temp UHB tape and added kapton to protect from short against the Pi (just in case it managed to work loose). It actually wedges in the space where the square of small holes is without the UHB tape but better to be safe than sorry.

It's now facing completely up to the sky in the position as normally mounted in most of the helicopter I fly.

I've done a comparative analysis between the antennae facing the back of the battery and the inside of the helicopter vs where it is now and the number of visible satellites seems to be unaffected (around 9-12) but the acquisition time is now quicker and also the number of momentary "GPS data lost" incidents seems to have gone from 1 per flight to 0.

...therefore this is a worthwhile improvement (how could it not be?!?)

[exfirepro]

Hi bladeslapper,

Thanks for the update. That looks like a much better arrangement for the GPS. Although you’re not seeing massive improvements at the moment, the fact that you are seeing zero dropouts bodes well for if/when you have to operate at low level in mountainous terrain (like up here in Scotland) or in bad weather. You should see a definite improvement (or at least minimal deterioration) in those type of circumstances.

Excellent effort.

Best Regards

Peter

[bladeslapper]

...if/when you have to operate at low level in mountainous terrain (like up here in Scotland) or in bad weather. You should see a definite improvement (or at least minimal deterioration) in those type of circumstances.

Most of my recent flights have been grovelling around in the Pennines with the cloud sitting across the summits so I guess it's had a pretty fair test and it's performed fine - there was 1 "network error" on the radar screen only which I couldn't explain but GNSS has been fine.