I'm having a problem getting a GPS 3d fix. Sometimes it will take a few minutes before it even gets one satellite, and I can sometimes wait another 10 minutes and it doesn't get any more in that time, and no 3d fix. I had 3 10 minute flights today with no lock.
It has been working previously, but was still slow to get enough satellites to get a 3d fix, sometimes 4 or 5 minutes.
I'm using a 3dr quad frame, and the gps is on the tier above the APM, and there's nothing too close to it that I can see that would be causing interference. Has anyone come across this before and have any idea how to fix it?
I am doing this outside under clear sky btw...
Do you have a picture to share? That might help..
Yep here you go.
Thanks for sharing. It looks good to me, but I'm courious if your rx is too close.
Something to try.
I don't think the RX would provide interference. It's only receiving, not transmitting.
I have had this issue in the past Glenn, but in the end it sort of went away. No idea if I did anything that fixed it, sorry! Though with mine I noticed on clear days it was hard to get a lock, whereas on overcast days I could get one almost right away.
I wonder if cutting a few of the bars in the top fibreglass plate would help... I'll do some testing with the top plate off completely and see if there's much difference.
>I don't think the RX would provide interference. It's only receiving, not transmitting.
OMG They surely do! Any receiver more advanced than a 1925 era crystal detector type receiver radiates.
I have the same issue sometimes getting the initial fix, however I'm using a APM 2.0 Purple and mine is on the lower deck. Sometimes hitting the reset button on the APM after you powered up and set on the ground where you plan on taking off from seems to help.
OK cheers, I'll give it a go. Last few flights I have had 1, maybe 2 satellites max for the duration of the whole flight, so no lock. What exactly does hitting the reset button reset? Does it just soft reboot the board?
If I remember correctly there was a problem with some Mediatek GPS were the current was lower than the 3.3 volts required.
Check the blue led, if it blinks slower than 1 per second then check the 3.3v that gets to the GPS.
if it's lower than 3.0v you could have a defective board.
Is that slotted cover fiberglass or carbon fiber? If it is carbon fiber, then that is absolutely your problem. If it is glass, it could be a contributing factor.
Simple rule, always works: do NOT cover your GPS antenna.
It's fibreglass. I tried it without the cover on at all the other day for 10 minutes and it still only managed 2 sats and no lock.
Blue light on the gps flashes once a second. Just tried cli erase/reset, and reuploaded firmware but no help.
OK, so right now there are a number of external forces against us using GPS these days. One of them being the largest amount of solar activity in years which seriously affects the GPS signal. The next is that there is an experimental wireless WAN trial going on in the US and one of it's biggest problems is that it too is interfering with the GPS signals. This means that more than ever, you must have a clear line of site to the sky with nothing on top of a gps module in order to ensure the best GPS access. So yes, any fiberglass, plastic, and especially carbon fiber will degrade the signal to the point your GPS may not lock. It's not a problem with our modules, they are very good, but all GPS receivers are experiencing this. I used to be able a couple of months ago get a lock inside my house, now it takes some time even outside. DIfferent areas and different days are being affected by the combinations of radio interference and solar flares.
Apparently, the one source was shut down by the FCC
Also, I curious to see what happens with the new telemetry modules released today.433MHz and 915MHz might have harmonics that could interefere with an already weak GPS signal.