GPS Ublox7 Dongle connection problems

[Chris-TT]

Received my unit this morning as promised! The unit seems to work except for the dongle. I actually have this exact same dongle for another unit I'm building, and was having problems getting a fix with that one too.

With CollisionAware the unit is working fine if I unplug the dongle, however with the GPS dongle inserted it won't find more than 3 satellites, and its been sat in the garden for 2 hours now. Any advice on how to get a fix, or have I been really unlucky and received 2 faulty dongles?

[Admin]

Hi Chris,

The dongle which shipped with the unit would definitely have been working when it was dispatched.
There are a lengthy set of automated installation checks which run checking on all of the interfaces.
If the GPS had not managed to get a good lock, then many other tests would have failed in addition
to the GPS failure

I am not an _expert_ on these matters but if the GPS needs to reload its ephemeris data this can take a while, how long has it been running, and I presume it has a good view of the sky

https://en.wikipedia.org/wiki/Time_to_first_fix

Thx
Lee

[rcalvert]

I've been trying it out today with an iPad.. Definitely not as good as the internal iPad GPS. Shame because SD seems to only use PAW for traffic if you 'go flying' with the Flarm source selected, so that means the navigation is now reliant on the PAW GPS receiver, not just traffic. I know that's an SD problem. Would be nice if traffic was separated from Location Services.

I'll try on Android tomorrow.

[PaulB]

I haven't tried with the unit I got today, but with the unit I built about 3/12 ago, the GPS dongle was better than the iPad's own.  How can you tell how many satellites it's picked up?

[Admin]

Hi

Definitely not as good as the internal iPad GPS

Thanks for the feedback, could you explain a bit more regarding what is different ?

Thx
Lee

[gvpsj]

I can only get the 'searching for satellites' on my SkyDemon with Nexus 7. I put it down to me as anything to do with computers goes wrong and I cannot get in touch with the grandchildren.

[Admin]

I can only get the 'searching for satellites' on my SkyDemon with Nexus 7. I put it down to me as anything to do with computers goes wrong and I cannot get in touch with the grandchildren.

Hi
Is this related to the ublox on PilotAware, I am confused

[exfirepro]

Received my unit this morning as promised! The unit seems to work except for the dongle. I actually have this exact same dongle for another unit I'm building, and was having problems getting a fix with that one too.

With CollisionAware the unit is working fine if I unplug the dongle, however with the GPS dongle inserted it won't find more than 3 satellites, and its been sat in the garden for 2 hours now. Any advice on how to get a fix, or have I been really unlucky and received 2 faulty dongles?

Lee,

I thought the reason it was decided to drop CollisionAware in favour of use of the GPS dongle (or mouse) was that the CollisionAware App was proving unreliable. Surely trying to use both will cause a conflict.

Is it not more likely that new users are simply not waiting long enough for the dongle to load initial Ephemeris data. IIRC my early attempts, the dongle needed to be set up with a clear view of the sky to the south and left in some cases for up to an hour before it started reporting useable data.

Regards

Peter

[Admin]

Peter

You are absolutely correct, using two GPS sources is not a good idea.
I was also concerned about the ephemeris data, but have not yet heard a follow up from Chris

Thx
Lee

[exfirepro]

I can only get the 'searching for satellites' on my SkyDemon with Nexus 7. I put it down to me as anything to do with computers goes wrong and I cannot get in touch with the grandchildren.

Lee,

Assuming Nexus is correctly connected to the PAW WiFi, sounds like Sky Demon is not properly set up to connect to 'FLARM' (i.e. the  6000 code in connectivity settings). Or am I missing something else.

Peter

[drvale]

I have exactly the same problem. The GPS dongle has been sitting in view of the sky for nearly 5 hours. As I understand the dongle should flash green when it has a fix, it doesn't. Log on via a browser 192...... and the home screen gives a status of 'satellites = 0'. If you then use the old fashioned CollisionAware on an iPad and SkyDemon then there is an error displayed of Multiple GPS sources. The CollisionAware is however linked to the iPad Location Services and then using SkyDemon and GO Flying and FLARM services does give traffic information clearly. HOWEVER frequently SkDemon flashes up searching for satellites, this is not very good as at that point your location is lost. As stated before if you Select Location Services from the Go Flying option then there is no traffic data displayed. I hasten to add Connectivity is set up correctly on the SkyDemon (latest version).
This is somewhat concerning as the previous system I built which I will present to the Flying club for ATC worked pretty damn well. Something has failed somewhere.
I have also tried under settings of changing Port 3 to GPS instead of Auto, however baud rate is still 4800.
I don't actually need the GPS fix for ADS-B output sourced from my GPS but of course I do for the Bridge unit.

[Admin]

Hi drvale

Can you please post a screenshot of the home page, you have posted under ublox7, I want to see it is correctly recognized

Thx
Lee

[DaveStyles]

I am wondering if these are power problems causing a brown out.

Can you both confirm you have them connected to supplies that can deliver 2A and you are using the cable supplied?

They were all tested here on the test rack, each was tested with the actual parts that went in the box with it. So each has actually been run up and tested by a hardware test program we have that verifies all the components.

The only thing I can think would be different would be the power supply.

David Styles
PilotAware Hardware.

[JCurtis]

Hi Chris,

The dongle which shipped with the unit would definitely have been working when it was dispatched.
There are a lengthy set of automated installation checks which run checking on all of the interfaces.
If the GPS had not managed to get a good lock, then many other tests would have failed in addition
to the GPS failure

I am not an _expert_ on these matters but if the GPS needs to reload its ephemeris data this can take a while, how long has it been running, and I presume it has a good view of the sky

https://en.wikipedia.org/wiki/Time_to_first_fix

Thx
Lee

Assuming the u-blox engine in the dongle is the EVA range they should acquire from a cold start in under 60 seconds. I have dev kit with the NEO8 series and performing a cold start on that today, with an antenna in the window of my office that faces NW, it acquired in 45 seconds.

The ident string from the USB enumeration is the same as that for the EVA, so providing here is a half decent signal they should acquire quite quickly.

They are very sensitive to power, and the dongle itself will have a converter to drop the 5v USB to 3.3v, the EVA can peak at 100ma.  Depending on the spec of that regulator if the power at the USB is too low it will not operate effectively at all.

[drvale]

I left the unit on all night, but not outside and there was no difference this morning. However when I plug in a USB extension lead I get 7 satellites and a 3D fix without any problems and all works. Remove the extension lead and plug the GPS dongle directly into the Pi and I momentarily may get 4 satellites but mostly 0. So I guess I am getting some shielding effect. When installed for real use then the GPS dongle will be on a USB extension lead so the Pi can be positioned protected from the sun.
Power supply is currently a mains iPad transformer (not an iPhone charger).