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droneprojetsn2 / ardupilot-mega

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MediaTek GPS startup time very long #660

Open GoogleCodeExporter opened 8 years ago

GoogleCodeExporter commented 8 years ago 
What steps will reproduce the problem?
1. Powered up the GPS (out the box), it took about 45 minutes to get first lock 
on position, this is because of a new Almanac was downloaded.
2.Subsequent startups take more than 10 minutes to get a lock, even if it's 
only a few seconds since power down. The blue status LED wass solid, but the 
ground station still says no fix for several minutes after the LED goes solid.
3.

What is the expected output? What do you see instead?
The specification says it will start up in 2 minutes, but is much longer than 
that, up to about 15 minutes. I would expect the GPS to have a warm start or 
hotstart for short power down cycles and get a fix much shorter than the 
current 15 minutes.

What version of the product are you using? On what operating system?
I have the most recent APM2.0, received this week. I am using Windows XP SP3.

Please provide any additional information below.
I am in the southern hemisphere, the GPS was in the window sill while doing the 
test, and saw between 4 and 7 satellites during the test once it had a fix.

Original issue reported on code.google.com by jeffrey....@gmail.com on 15 Jun 2012 at 11:28

GoogleCodeExporter commented 8 years ago 
Almost certainly RF interference with the GPS; have posted in forums soliciting 
the reporting user's attention to work with him to verify this diagnosis.

Original comment by std...@gmail.com on 24 Jun 2012 at 6:57

GoogleCodeExporter commented 8 years ago 
I suspect that there might be an initialization issue. If I do the same test 
using a battery powering the circuit then the GPS locks within a reasonable 
time, about 2-3min, even though I still have the USB cable attached. I have 
exactly the same test setup, but the only difference is I have my receiver, a 
servo and battery pack. It could also be a problem with noisy power coming from 
the USB.

Original comment by jeffrey....@gmail.com on 24 Jun 2012 at 9:50

GoogleCodeExporter commented 8 years ago 
I think we can close this issue. I think there might be some other problem 
here. Maybe there can be an option to install a battery on the APM 2.0 add-on 
board to help speed up the start-up time.

Original comment by jeffrey....@gmail.com on 2 Jul 2012 at 9:12