paiprashanth / ardupilot-mega

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No GPS fix from APM2 #624

Closed GoogleCodeExporter closed 8 years ago

GoogleCodeExporter commented 8 years ago
What steps will reproduce the problem?
Waiting for gps fix from 1 to 60min 

What is the expected output? What do you see instead?

everytime i had an excelend 3dfix and perfect flights both manual and auto. Now 
i cant get a 3dfix even if i wait for hours, and i read at mission planner Via 
telemetry. i tried reseting my apm2 board,  
but problem persists.

-GPS status = 1
-GPSHDOP = 9999
-SAT COUNT = 0 

I also connected my old GPS, from my APM1, to the external GPS. Blue led on 
external GPS went solid, but mission planner reported no fix

What version of the product are you using? On what operating system?
Arduplane 2.33, latest 1.1.80 64bit MSI mission planner. Windows 7 64bit

Please provide any additional information below.
Everything else, including leds, manual control, stabilize control work as per 
wiki. 

-can i upload my logs here from my recent flights with out gps fix and my old 
ones with perfect 3dfix?
-can i just use my old GPS,in order to finish  my job, in time?

Original issue reported on code.google.com by jamesma...@gmail.com on 6 May 2012 at 7:45

GoogleCodeExporter commented 8 years ago
sounds likea  gps issue to me. the only reason you would have such a low sat 
count is if there was a problem with the gps antenna

Original comment by Meee...@gmail.com on 9 May 2012 at 12:40

GoogleCodeExporter commented 8 years ago
either that or power.

Original comment by Meee...@gmail.com on 9 May 2012 at 12:40

GoogleCodeExporter commented 8 years ago
THANKS YOU!!!

I've done all the test mentioned on wiki and forum, all logs, tlogs, cli  dont 
report lang long, so it must be a GPS issue. as you said, probably with the 
antenna. I use an external BEC capable for 7A with 5,23v constant from outputs 
using the jumber, so i believe power its not an issue.

plz verify: Can i just solder something, like Chris Anderson mentioned back on 
the APM2 presentation Blog, in order to use my external GPS?? iam really on a 
rush finishing my thesis!! 

Thanks again
james

Original comment by jamesma...@gmail.com on 9 May 2012 at 9:26

GoogleCodeExporter commented 8 years ago
I also had the problem today. I have an APM 2 V2.4.1 and a UDB4 both using 
Media TEK GPS units. I was not getting a 3D fix with the APM 2 so I swapped out 
the GPS with no fix, then the GPS cable with no fix, then checked the GPS on 
the UDB 4 and it got a 3D fix within about 80 seconds. Switched the unit I had 
connected to the APM 2 still no lock. Installed the pre-compiled ArduPlane V 
2.33 binary and got lock on the APM 2 in about 3 minutes. Downloaded my edited 
and compiled binary and repeated the test and got lock again .. so thought 
problem is solved. I then reconnected my lipo, ESC and board into the plane and 
then could not get a 3D fix again. One thing though it was very hot (around 40 
degC) and the Media TEK GPS units were hot to the touch. I wonder if its not a 
temperature related issue? Any ideas??

Original comment by granto...@mweb.co.za on 9 May 2012 at 1:26

GoogleCodeExporter commented 8 years ago
I measured Gnd and Vcc traces just to make sure,again with an accurate voltage 
meter. Showing 3,31v.  Another question: can i order a new daughter board?? Iam 
really really hurry!!

Original comment by jamesma...@gmail.com on 10 May 2012 at 8:08

GoogleCodeExporter commented 8 years ago
How long does it take to get satellites, because I think I have the same 
problem, blue led is still blinking and I don't manage to get a GPS Fix with 
APM2 (fw is 2.5.5 beta)

Original comment by airma...@gmail.com on 11 May 2012 at 5:51

GoogleCodeExporter commented 8 years ago
Prob solved (in a way).  went out on clear sky again, but this time with my usb 
cable and nothing connected to APM 2.0,  In 1 minute it had 7 sats with 
excelent reception. 
i disconnected, and connected all my gear. this time i connected via 3dr 
radios.. like a miracle it started finding sats (slower this time) until 7 sats 
again...  So i suppose problem some how solved with the usb conection.  Its a 
bug? usb voltage and no gear helped??   Any suggetions?

Original comment by jamesma...@gmail.com on 12 May 2012 at 8:37

GoogleCodeExporter commented 8 years ago
A solution that worked for me, that may also help diagnose the overall problem. 
Replace the power jumper regardless of having two power feeds to front and back 
of APM2. When presented with symptoms described above, It solved this problem 
for me. CAUTION! may produce other issues, not flight tested yet.

Original comment by g...@exchangeplaza.com.au on 15 May 2012 at 1:39

GoogleCodeExporter commented 8 years ago
Problem indicated solved. Not software related

Original comment by andreas@antonopoulos.com on 5 Jun 2012 at 5:57

GoogleCodeExporter commented 8 years ago
"Problem indicated solved. Not software related". 
Sorry, how do I find the resolution? I'm also suffering the same issue.
cheers, Owen

Original comment by stickite...@yahoo.com on 7 Jul 2012 at 7:32

GoogleCodeExporter commented 8 years ago
Why solved? So many people still have the same GPS-Lock problem. An autopilot 
is absolutly useless for me without GPS.

Original comment by mueller...@gmail.com on 13 Jul 2012 at 11:33

GoogleCodeExporter commented 8 years ago
I have found a solution that works for me so far, dedicated 5v ubec to feed 
apm. I now get lock in under a minute. Not code, not noise, not rf blocking. 
I'll do a full rebuild to test properly, but it's looking very promising!

Original comment by stickite...@yahoo.com on 13 Jul 2012 at 12:17

GoogleCodeExporter commented 8 years ago
[deleted comment]
GoogleCodeExporter commented 8 years ago
same problem,    no gps 3d fix.  I tried an external dedicated bec,  the 
problem continues, put a gps back up batery, and the problem  stil tehere... 

then i conect to the USB and got lock in a few minutes...

any solution?    
yeah I know,   put my notebook in the plane...

Original comment by fer.luis...@gmail.com on 20 Oct 2012 at 8:32

GoogleCodeExporter commented 8 years ago
Some ppl here might freak a little :) but I solved it my jumping JP1, powering 
the input rail from UBEC + bridging pos & neg to output rail + using APM 
module. It's the only way I could get it to work reliably.

The cause of the issue - I think we've (on this thread) blown something on the 
APM, hence the additional power sources.

Original comment by Taq...@gmail.com on 12 Jun 2013 at 8:42

GoogleCodeExporter commented 8 years ago
all look good on apm and we dont have a gps fix. red light is on and blue light 
is flashing no lock . 
apm planner say no gps

it was working before we do a code update an now nothing . 

Original comment by ssard...@gmail.com on 27 Mar 2015 at 9:33