Ultimate GPS cannot get fix

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turbulence21
 
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Joined: Mon May 06, 2013 1:58 pm

Ultimate GPS cannot get fix

Post by turbulence21 »

Hi,
I recently bought one of your Ultimate GPS units but I cannot get a GPS fix with it. I installed the coin cell battery and the GPS unit keeps the right time and date, but never gets a GPS fix.

I have tested it in my window with a clear view of the sky and in my car, also in the open for over an hour. I have tried connecting the GPS unit to 2 different arduino's powered with a wall wart and the other from a battery and still no luck. Do you have any other suggestions as to why I cannot get a GPS fix? I've copy and pasted some of the NMEA output from the unit below.

$PGGTOOPP,,111,,22**66E
$GGPPGGGA,,11881188499..008877,,,,,,,,,00,,0,,,,,MM,,,,MM,,,**44A
$GGPGGLLLL,,,,,,,,11811884499..08877,,VV,NN**778
$$GGPGGSAA,,A,,1,,,,,,,,,,,,,,,,,,,,,,,*11E
$$GPPGSSV,,1,,1,,000*779
$$GPPRMMC,,188188499.00877,VV,,,,,,,00.000,,0..000,006005113,,,,,N**4EE
$GGPVVTGG,00.000,,T,,,MM,00.000,,N,,0..000,KK,NN*332
$$PGGTTOPP,,1111,22*66EE
$$GGPPGGGA,,1881188550.0087,,,,,,,,,0,,00,,,,,MM,,,MM,,,*4422
$$GPPGLLLL,,,,,,,,1188188550..08877,,VV,,N*7700
$GGPPGSSA,,AA,,11,,,,,,,,,,,,,,,,,,,,,,,*11E
$$GPPGSSV,,1,,1,,000*779
$$GPPRMMC,,188188500.00877,VV,,,,,,,00.000,,0..000,006005113,,,,,N**466
$GGPVVTGG,00.000,,T,,,MM,00.000,,N,,0..000,KK,NN*332

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adafruit_support_bill
 
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Joined: Sat Feb 07, 2009 10:11 am

Re: Ultimate GPS cannot get fix

Post by adafruit_support_bill »

I have tested it in my window with a clear view of the sky and in my car, also in the open for over an hour.
A first-time fix can take a while, but in the open for an hour should be plenty of time. Contact [email protected] with a link to this thread.

trimotor_fan
 
Posts: 5
Joined: Thu May 16, 2013 11:53 am

Re: Ultimate GPS cannot get fix

Post by trimotor_fan »

Hello again - now that we're getting my battery holder problem resolved I've encountered another problem. I received the USB to TTL serial cable and was finally able to power up my Ultimate GPS breakout board on my Raspberry Pi. Everything appeared to be going well - the light on the Ultimate GPS began flashing about once a second BUT as Raspbian was "Waiting for /dev to be fully populated" the light on my U-GPS stopped flashing at all.

ttyUSB0 is present in /dev but doing sudo cat /dev/ttyUSB0 shows nothing. (These are steps detailed in the Adafruit Learning System tutorial "Adafruit Ultimate GPS on the Raspberry PI".) Starting gpsd displays no errors but nothing ever shows on the output from "cgps -s". I tried moving the U-GPS closer to the window, then put it outside the window as far as the USB to TTY serial cable would allow. I then added a 12' USB cable to allow getting further from the house, all to no avail.

I did discover that the light on the U-GPS will again flash at once a second if Raspbian on the R-Pi is halted or if Raspbian is restarted the ligh will flash from the completion of the halt until the "Waiting for /dev . . . ." message is again displayed, it then goes out again.

Am I correct in understanding that the U-GPS should either be flashing at about once a second or one every 15 seconds?

Is this the proper place to post this situation?

Would appreciate any thoughts on this issue.

trimotor_fan
 
Posts: 5
Joined: Thu May 16, 2013 11:53 am

Re: Ultimate GPS cannot get fix

Post by trimotor_fan »

An update to my previous post re: Ultimate GPS on R-Pi. I tried to run the U-GPSon a Windows PC with the S/W packages listed in the U-GPS tutorial (MT3339 GPS PC Tool (windows only) and Mini GPS tool (windows only)) with Essentially the same results. EXCEPT that now after a few minutes the on-board LED switches to blink every 15 sec. (Maybe I wasn't patient enough when I originally tried the R-Pi instead of the PC.)

Anyway, the PC was not able to receive anything from the U-GPS. I reinstalled the Ultimate GPS on the Raspberry PI and did eventually get the 15 sec blink of the on-board LED but still nothing transmitted from the Ultimate GPS.

Help, I'm at a loss here.

walterpw
 
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Joined: Mon May 19, 2014 5:27 am

Re: Ultimate GPS cannot get fix

Post by walterpw »

Hi Adafruit,

I had a question about the Ultimate GPS unit, I am following the tutorial (https://learn.adafruit.com/adafruit-ult ... ter-wiring), I have deployed the blank Arduino Sketch, have the connections wired correctly, opened the Serial Monitor and am noting two unfortunate things: the module's leds aren't flashing (indicating satellite searches), nor can I get any readout via Rx Tx connections.

It's a version 3 GPS unit. Just curious if there were any suggestions if I may be incorrectly using it?

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adafruit_support_mike
 
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Re: Ultimate GPS cannot get fix

Post by adafruit_support_mike »

Post a photo of your hardware and connections and we'll see if we can find anything.

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