SparkFun Forums

[tiagofumo]

I'm having problems using a sr-92 gps... this one:
http://www.cutedigi.com/pub/GPS/SR-92_U ... ual_EN.pdf

I can't get any readings here... I get readings like this:


$GPGGA,145158.057,,,,,0,00,,,M,0.0,M,,0000*58
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,145158.057,V,,,,,,,020407,,,N*42
$GPVTG,,T,,M,,N,,K,N*2C
$GPGGA,145159.057,,,,,0,00,,,M,0.0,M,,0000*59
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,20,00,000,,10,00,000,,31,00,000,,27,00,000,*7C
$GPGSV,3,2,12,19,00,000,,07,00,000,,04,00,000,,24,00,000,*76
$GPGSV,3,3,12,16,00,000,,28,00,000,,26,00,000,,29,00,000,*78
$GPRMC,145159.057,V,,,,,,,020407,,,N*43
$GPVTG,,T,,M,,N,,K,N*2C

you see that I can't see any longitude or latitude in there :S

I don't know what to do =(

I connected it to my xbee pro on transparent mode and I have one at my computer so it sends data to the one in my computer, and the gps is actually outside my house, so It should be capturing data... but it's not :S

the xbee connection is great, but the gps is apparently not returning latitude and longitude data...

and look at the GPGSV, there are 12 satelites around here... but there is no data... ???

if someone can help me please... that would be great =)

thx

[fll-freak]

Interesting, I could not anywhere that Sparkfun sells this unit. Does "cutedigi" have a forum you could ask for help?

Most GPS problems are due to:
1) Bad serial coms (not your issue)
2) Bad/noisy/insufficient power
3) No or obstructed view of the sky (foliage can be a killer)
4) Poor antenna
5) No waiting long enough for a lock
6) Incorrect wiring.

[tiagofumo]

Ok that this gps is not from sparkfun... sorry about that...

but I'm having a problem here... I mean, I have xbee explorer from sparkfun, I have things from sparkfun that I'll be using with it...

I just would like to know if someone had this problem already with any other kind of GPS and what this person did to solve the problem...

just that...

edit: the last time I used my GPS module was some months ago... and it's with a bit of dirt on the top of it (which I believe is the ceramic antenna)

so, is that a problem? if it is... how do I "fix" it?

the antenna has a small steel ball on the top of it (like most of ceramic antenna gps do)... and I have some paste here that I use before soldering...
It's like flux but it needs a bit of heat to work, so when I get it on the pins I'm going to solder, I get the soldering iron in it, and it removes the oxidation...
but I don't know if I'll damage my gps if I get the soldering iron so close to its antenna

any help on all this stuff?

[fll-freak]

1) It is not an issue that you posted here about a product that SFE does not sell. But you might get a better reply from people that might have experience with it.

2) Regarding 'dirt' I am lost with your post. It sounds like at some point the unit was working, but since then the ceramic antenna got covered in flux? And you are wondering how to clean it? Anything that would attenuate the GPS signal would be an issue. GPS signals are tiny as it it. Looking at them with a spectrum analyzer, you can hardly see the signal in the all the noise. If you flux has a resonance frequency of the L1 frequency set, you might have a problem. I know that water is a killer. Coat an antenna in a film of water, and you can pretty much guarantee a loss of lock. Since in my location it rarely rains flux, I do not know if this is your problem. As for cleaning, you might be out of luck. If memory serves me, the ceramics they use are porrous. Once the flux gets in, it is not likely to come out.

[tiagofumo]

1) It is not an issue that you posted here about a product that SFE does not sell. But you might get a better reply from people that might have experience with it.

2) Regarding 'dirt' I am lost with your post. It sounds like at some point the unit was working, but since then the ceramic antenna got covered in flux? And you are wondering how to clean it? Anything that would attenuate the GPS signal would be an issue. GPS signals are tiny as it it. Looking at them with a spectrum analyzer, you can hardly see the signal in the all the noise. If you flux has a resonance frequency of the L1 frequency set, you might have a problem. I know that water is a killer. Coat an antenna in a film of water, and you can pretty much guarantee a loss of lock. Since in my location it rarely rains flux, I do not know if this is your problem. As for cleaning, you might be out of luck. If memory serves me, the ceramics they use are porrous. Once the flux gets in, it is not likely to come out.

I think the word was dust and not dirt... some people went to my home, to perform a maintenance... and it got a lot of dust on the home... including the GPS module which was on my desk...

so, I don't know what to say but... so I asked if I could use flux to take of the oxidation on the antenna... but no problem with it...

I don't know why it's actually getting some stuff now... I'm getting some data... I putted at google maps and looks like I'm at the next home but I believe is just a minimum issue... it's actually working... and that makes me happy...

I don't know if it needs time to find out the how to work but I left it there for like 15 mins, and it's now giving me some data... which is nice =)

I mean, now I know the possible problems in the future that you mentioned, and that I should not use any kind of flux or anything like that on the module to clean it or etc...

thx =)

edit: after I send this reply, it just got bad again lol... I'm gonna try to go around with it to see what I can find out =)

cya

[fll-freak]

I don't know why it's actually getting some stuff now... I'm getting some data... I putted at google maps and looks like I'm at the next home but I believe is just a minimum issue... it's actually working... and that makes me happy...

Are you doing this indoors? It almost sounds like it from your sentence "at the next home". Please tell me your antenna is outdoors? Your roof will lower the signal enough that you will not lock. Even next to a window is not enough for a good lock. The window will only allow you to see a small amount of the sky. If you have 4 satellites in view, you would get a poor position. If less than 3 satellites are in view you will get nothing.

Do this test outdoors away from obstructions.

[tiagofumo]

I don't know why it's actually getting some stuff now... I'm getting some data... I putted at google maps and looks like I'm at the next home but I believe is just a minimum issue... it's actually working... and that makes me happy...

Are you doing this indoors? It almost sounds like it from your sentence "at the next home". Please tell me your antenna is outdoors? Your roof will lower the signal enough that you will not lock. Even next to a window is not enough for a good lock. The window will only allow you to see a small amount of the sky. If you have 4 satellites in view, you would get a poor position. If less than 3 satellites are in view you will get nothing.

Do this test outdoors away from obstructions.

my english is not very good as you might have noticed... things are alright now... don't worry about =)

[fll-freak]

my english is not very good as you might have noticed

Your English is better than my [fill in your native language here]!