Gps connection

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Hello everyone I have a minor or major problem and could use all advice.i have a p4p not a scratch or bump,never been crashed but for some reason it will only detect 3-4 satellites.ive tried compass/imu calibration,different USB plugs,different phones/tablets,I've tried launching from several different locations around the city.skies are very clear not a cloud in site.when the bird is launched it's in vision mode and will only climb about 24 ft before max altitude is reached unless I put it in attic mode then I can climb approximately 100ft.any help will be gladly appreciated
 
There is a P4 category where this post should belong, not in "general".

Anyway it matters less whether the sky is blue, and more whether a portion of it is blocked. ie. by buildings, which usually are common in the city.

The GNSS module within the drone is independent from the rest (well, kind of - it gets configured by the FC on power on, then it just works without further instructions). So most of the actions you've taken are irrelevant. Except changing location, that one might have helped.

Anyway looking here, seem like Ph4 uses the same GPS board as Ph3:
Meaning it's at top of the drone, behind an adhesive shielding.

What you should do in carefully investigate the GPS board. Especially whether the ceramic antenna isn't broken, the copper patch is whole, and soldering holds.

Most people have trouble visualizing propagation of microwave EM fields; but I can tell you even a small etching in the copper of the patch antenna causes large changes in the ability to receive signals.
 
Yes I'm aware of the gps board location,I've torn down and repaired several p4's,but I wanted to make sure I wasn't over looking something before I dismantle the bird.i seen in another thread someone said something about redownloading firmware.do you think that could be an issue? Just kinda weird it's grabbing 3-4 satellites sometimes 5.would a defective gps board do that? I would assume a defective gps board or components wouldn't allow it to connect to any satellites
 
Yes I'm aware of the gps board location,I've torn down and repaired several p4's,but I wanted to make sure I wasn't over looking something before I dismantle the bird.i seen in another thread someone said something about redownloading firmware.do you think that could be an issue? Just kinda weird it's grabbing 3-4 satellites sometimes 5.would a defective gps board do that? I would assume a defective gps board or components wouldn't allow it to connect to any satellites
And I'm not around any buildings,I go to different locations that are open fields,only a few trees are in the areas
 
i seen in another thread someone said something about redownloading firmware
No. If there was an issue with specific firmware, it would be already well known.


Just kinda weird it's grabbing 3-4 satellites sometimes 5.would a defective gps board do that?
If the u-blox receiver didn't worked, or the issue would be in FC-GPS board connection, then there would be no satellites at all. Small number of satellites means just poor reception.

Note that the u-blox chip does all the positioning-related computations. The FC receives only what you see on the screen - coordinates and # of satellites (well, there are few more minor statistics, like expected error and # of sats under each GNSS system).
 
No. If there was an issue with specific firmware, it would be already well known.



If the u-blox receiver didn't worked, or the issue would be in FC-GPS board connection, then there would be no satellites at all. Small number of satellites means just poor reception.

Note that the u-blox chip does all the positioning-related computations. The FC receives only what you see on the screen - coordinates and # of satellites (well, there are few more minor statistics, like expected error and # of sats under each GNSS system).
I just took it up as far as it will go as it reached 5 satellites.still not enough for gps flight.im stumped!
 
Screenshot_20230212-122348.png
 
This occurred on a totally different system, but still with a Ublox GPS receiver chip. It was with the GPS in the handheld controller for a Yuneec H+ drone. The cure was replacing the patch antenna to the GPS receiver. I never could determine what internal issue caused the antenna to go bad, but replacing it cured the low satellite count that was occurring.

I am not familiar with the GPS board on the P4, but most drone aircraft have the Patch Antenna as part of the GPS board assembly. You may need to get a new GPS board to cure the issue.
 
Thanks for all the advice,greatly appreciated.i just ordered the replacement,will do the swap when it comes in.will let you guys know the outcome
 
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You fellas are genius! Changed the gps module couple hours ago and instantly got 14 satellites then upwards of 20.good gps connection,home point recorded and can fly high and far.you guys are awesome thanks for the advice
 

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So glad you are once again airworthy!

My guess is an issue inside the patch antenna (flat square ceramic or fiberglass block) on the side facing the sky. I am still wary of quality control from many manufacturers. It just doesn’t seem to exist. In cases like this it all comes down to the solder, flux, and workmanship. An inconsistency in any one of them can cause failure after months of operation in the field.
 

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