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Recommendation for GPS Receiver for a complete noob

Hi, first post here, though I have lurked for a bit.
I must confess that I'm a complete noob at this, I've had an XDA IIi for over 6 months and done absolutely nothing to it, it's as virgin as the day it came out of the box. Also, I've never had a GPS Receiver before, nor SatNav.
Anyway, I've ordered TomTom software and need a GPS Receiver, but I have no idea on what basis to compare the miriad of different GPS Receivers out there, so am humbly asking for your recommendation. If you could also point me at a noobie guide on all terms regarding GPS, or explain what they mean, that would be great.
99% of usage will be in the car with my XDA in a cradle, though I'm guessing I will have to swap over the 2 charger cables, however occassionally I'd like to roam on foot with Sat Nav (usually in London). So I'm guessing I would like a BlueTooth GPS Receiver that comes with a car charger and main charger.
I have no idea what Cold Start, Warm Start, or Hot Start mean, nor what Update time is for or what's good or bad for these values. Why is Baud rate or NMEA output protocol important? What are the pro's / cons of internal or external Antenna's and wtf does an external Antenna look like and how does it work, hang out the window?? How many "channels" should I have, and what difference does it make anyway?
Sorry for all the questions, but none of the purchase sites seem to do a noobie guide aimed at my level, they all assume you know what they're talking about! :roll:
Thanks in advance.

Can no one even point me at a decent online guide that explains what all these things mean?

GuiltyCol said:
Hi, first post here, though I have lurked for a bit.
I must confess that I'm a complete noob at this, I've had an XDA IIi for over 6 months and done absolutely nothing to it, it's as virgin as the day it came out of the box. Also, I've never had a GPS Receiver before, nor SatNav.
Anyway, I've ordered TomTom software and need a GPS Receiver, but I have no idea on what basis to compare the miriad of different GPS Receivers out there, so am humbly asking for your recommendation. If you could also point me at a noobie guide on all terms regarding GPS, or explain what they mean, that would be great.
99% of usage will be in the car with my XDA in a cradle, though I'm guessing I will have to swap over the 2 charger cables, however occassionally I'd like to roam on foot with Sat Nav (usually in London). So I'm guessing I would like a BlueTooth GPS Receiver that comes with a car charger and main charger.
I have no idea what Cold Start, Warm Start, or Hot Start mean, nor what Update time is for or what's good or bad for these values. Why is Baud rate or NMEA output protocol important? What are the pro's / cons of internal or external Antenna's and wtf does an external Antenna look like and how does it work, hang out the window?? How many "channels" should I have, and what difference does it make anyway?
Sorry for all the questions, but none of the purchase sites seem to do a noobie guide aimed at my level, they all assume you know what they're talking about! :roll:
Thanks in advance.
Click to expand...
Click to collapse
OK basic reccomendation. Get a Globalsat BT-338. A popular and well liked high performing device at a reasonable cost.
What you need to look for in a receiver is the chipset. You want one with a SIRF III chipset because it will provide the best reception in heavily built up areas. You want to avoid X-TRAC because it's laggy.
With regards to charging, you probably won't need to be continuously charging, (look for battery life on the device specs. You want around 20 hours per charge). However you could get a cradle which charges both, or a Y-Cable which will also charge both the xda and the receiver if need be.
Cold start refers to how long the receiver takes to get a fix from the very first time it is used, or after it has had no battery, it needs to work out where you are on the planet and can take up to 5 mins. After this you will be more likely to just do warm starts, by which the receiver uses your last known location to get a rough guide of where you are, this should take less than a minute. A Hot start means you havent moved from your last know location, theis should take 30 seconds to get a fix. These times are measured as TTF- Time to Fix, ands should also be on the device specs.
The Protocol is the format that the data is passed onto the xda software. Most software expects NMEA data, as this is the most commonly used. The baud rate is just how fast the device can communicate with the xda and dosn't make a lot of difference the BT-338 has a baud rate of 38400, but I've used a device with a baud rate of 9600 and can't say I noticed a difference. A SIRF III device is unlikely to need an external arial, unless you have heat reflective windows all round your car, and even then unlikely. A good SIRF III receiver will work from inside a closed glove box. An older SIRF II chipset may need an external antenna. These are usually little magnetic squares that you stick to the roof of the car, with a cable that connects to the receiver inside. Buy a SIRF III and forget about those.
Channels, most SIRF III receivers are 16- 20 channels, this is how many simultaneous satellites the device can track at once. Anything over 16 is pure bonus as you are probably unlikely to get more than 12 satellites in your line of sight anyway.
That seems to cover everything except cost. Expect to pay between £50 and £80.
and check out www.pocketgps.co.uk

Thanks Gajet, that was everything I wanted in an answer. Much obliged.

My Globalsat BT-338 arrived yesterday. Had a few problems working out which serial port it was using but got there in the end. Also the middle LED seems to flash or hold solid with a mind of it's own. But apart from that, works like a treat, and as the review said, works fine in my glovebox too, which is nice.
Thanks again.

The middle LED just tells you if you are getting a good satellite lock. If it stays steady then you are not getting enough satellite signal for a lock. There is a program on the CD that can tell you the satellite signal strength. Most nav programs have that feature as well.
I've been playing with mine for a few days and I am amazed by how fast it can lock onto satellite signal. If you compare with other non-SirfIII chipped GPS the difference is almost night and day.
I did have some BT/COM port issue if I run an alternate nav program. It wouldn't connect BT anymore until I rediscover it. But staying with one program (iGuidance) it works perfectly.

> I did have some BT/COM port issue if I run an alternate nav program.
I had this problem too. If I ran up the GPSInfo program, then TomTom would fail to find the GPS Receiver.

Who brought a 2006 thread back to life...Thread closed, Thank you.

External antenna possible to boost reception?

So I was playing with my g2 and noticed it had a fm radio installed so I opened it and low and behold it worked after inserting a headset. This is where my question comes from. It said I had to put in the headset in order to have an antennae... I then remembered a few years back when phones had a little port for an external antenna to boost cell phone reception that worked amazingly. In some cases I could get great reception in places I previously had no bars at all. Are there any accessories that could hook into my phone headset jack and do that now?
Sent from my HTC Vision using XDA App

The FM radio antenna works through the headphone jack, yes. But the phone antenna doesn't, it's inside the phone and I suspect you'd have to do some hardware modding to be able to do anything like this, sorry.

A standalone cell repeater / booster would work in a fixed location (or even in a car/boat/RV). They are not exactly pocketable though.

Anyone remember those little strips that you'd place behind the battery door, or under the battery? I suppose those never worked... Worth a try maybe?

xdviper said:
Anyone remember those little strips that you'd place behind the battery door, or under the battery? I suppose those never worked... Worth a try maybe?
Click to expand...
Click to collapse
Did some research on those and found them to be bogus, especially for smart phones of today.

http://m.youtube.com/#/watch?deskto...e.com/watch?v=zwNZGuKzGWY&v=zwNZGuKzGWY&gl=US
This is what I was referring to actually
Sent from my HTC Vision using XDA App

Bloody crap gps.

Anybody else's gps connectivity generally crap? Seems to take for ever to connect then struggles to keep a connection.
Any known software conflicts? Running stock 2.35 rom.
No trees, walls, flying saucers in the way and Tried various gps info and fixer appear but to no avail.
Starting to really p*ss me off now.
Ta!
Sent from my HTC Desire S using XDA App

Yes, happens to me too. expecially when i go for walks. It takes reaally long time to load. Use Gpsfix ( Google it, Not able to post link because of post count) . It makes to process a lot faster.

khamoshpathak said:
Yes, happens to me too. expecially when i go for walks. It takes reaally long time to load. Use Gpsfix ( Google it, Not able to post link because of post count) . It makes to process a lot faster.
Click to expand...
Click to collapse
Be warned that gpsfix adds air push adverts to your phone. You may want to also instal add-on detector to find and remove them.
OP: Are you using a case? You may find that without root, you can't change the agps server location (mine was set to Asia by default) so it takes a while to lock pulling satellite info via 3g from the other side of the planet!
GPS Status and toolbox (which doesn't need root) forces an AGPS data download on startup and might help. Make sure 3g is on.
https://play.google.com/store/apps/details?id=com.eclipsim.gpsstatus2
Sent from my HTC Desire S using xda premium

Have observed that the GPS fix times are ROM dependent during my journey through many many excellent ROM's available for Desire S. I have even tried the AGPS fix which is recommended in the Dev section which was indeed helping to get a faster fix but the fix wasnt stable afterwards, especially while using apps like endomondo sports tracker..
The first ROM I saw that the GPS was excellent was in MIUI (GB) - without any AGPS or any other market apps or hacks I began to see a fix within 20 secs. Now, I'm presently on Reaper 2.2 (without AGPS fix) and the GPS continues to be excellent (<20 sec fixes).

I'm using ice cold sandwich with GPS+agps fix and find satellites in 3 seconds
Sent by my fingers to your head.

GPS fix issues can be as simple and HW-related as bad contact between the phone cover that includes GPS antenna (I guess it's the lower cover, but it might be an upper cover too), and the golden connector pin on the board. If you test all possible SW workarounds and they don't help - try to locate the antenna and make sure the connection is firm. Look for Vibrant GPS problems, they had such problem in the early batches.

For me the thread AGPS Patch Desire S 3.1 & 2.2 | GET BACK TO RAPID GPS LOCK, CAN LOCK ONTO MORE SATS helped a lot to get rapid GPS lock. Though, I'm not sure if root is needed for all installation methods. Good luck!
P.S.: The described patch is allready included in some custom roms like Endymion.

Jack_R1 said:
GPS fix issues can be as simple and HW-related as bad contact between the phone cover that includes GPS antenna (I guess it's the lower cover, but it might be an upper cover too), and the golden connector pin on the board. If you test all possible SW workarounds and they don't help - try to locate the antenna and make sure the connection is firm. Look for Vibrant GPS problems, they had such problem in the early batches.
Click to expand...
Click to collapse
The GPS and WiFi antennas are in the upper (camera lens) plastic cover, and, yes they use sprung pins to (hopefully) make connection. The phone antennas are in the lower (battery) cover.
I have found that many types of case massively deteriorate GPS reception of my phone. What puzzles me is why some users seem to be entirely unaffected; it's almost as if individual phones vary; even as an experienced engineer I cannot expalin it.

Since cases create mechanical pressure on the phone body and the contacts are very sensitive to their cover bending (they usually have a very light touch), it might be one of the reasons for reception deterioration. Sometimes even a hit of a falling phone can either destroy reception or improve it - saw it happening live on friend's Desire HD, it was very funny to see how the GPS that wouldn't lock properly for weeks, after the phone fell, started locking in 5 sec all of a sudden. Pure plastic cases shouldn't matter for reception otherwise, or at least I can't think of how can they possibly interfere.
By the way, Desire S' GPS is a bit on a weaker side - I compared it side-by-side to my MT4G, and it's always several lock seconds and a couple of locked satellites below. It should be plenty powerful for a good fast lock, though, and that's why I suspect disturbance on the HW side, rather than SW misconfiguration.

now that you guys are talking about cases, I was using a case mate barely there case before... long time ago gps fix was on the slow side (around a min).. but somewhere down the line of moving across ROM's I moved to MIUI GB (with the case still present) and the fix improved (without any AGPS patches or GPS fix apps).. now I dont use the case and have moved to Reaper CM7 based ROM and the GPS fixes are brilliant... looking at the build of Desire S I dont think that the contacts for GPS, wifi or phone antennas are at fault or can change with just a fall.. I can't pin the problem but I definitely feel removing the case has helped the gps fixes.

Jack_R1 said:
GPS fix issues can be as simple and HW-related as bad contact between the phone cover that includes GPS antenna (I guess it's the lower cover, but it might be an upper cover too), and the golden connector pin on the board. If you test all possible SW workarounds and they don't help - try to locate the antenna and make sure the connection is firm. Look for Vibrant GPS problems, they had such problem in the early batches.
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Click to collapse
Seems legit. By so far I am experiencing also constant GPS problem. It really might be the problem. I will make a try and let here know how it goes.

Forwox said:
Seems legit. By so far I am experiencing also constant GPS problem. It really might be the problem. I will make a try and let here know how it goes.
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Click to collapse
Clining contact did not help..
adding some wires to the antena (made some improvement)..
Than i orderd "new antena" for 8 eur form "Taiwan".
no may fix quick and with 12-18m an i does not lose fix anymore..
(and now i have working gps.. after 1 year of trying roms and waiting for better radio firmwares)
---------- Post added at 08:11 PM ---------- Previous post was at 07:38 PM ----------
fasty said:
What puzzles me is why some users seem to be entirely unaffected; it's almost as if individual phones vary; even as an experienced engineer I cannot expalin it.
Click to expand...
Click to collapse
You have first version of gps antenna which has been silently improved..
I bougt new antena (upper cover) and wifi antena is printed the sesame number, but gps antena has an number increased by 10. (which by my means, mean new version)
And with "new antena" i have reliably working gps now.
(htc service (here in SLO) wanted th have the phone one service for 14 day-s thats teh reason i didnt apply for warranty repair)

on stock rom gps is really slow..i have that experience before,actually one of the reason i rooted mine...now,got gps locked in less than 15 minutes...(my gps always turn off,on when want to use navigation only)

oTeMpLo said:
Clining contact did not help..
adding some wires to the antena (made some improvement)..
Than i orderd "new antena" for 8 eur form "Taiwan".
no may fix quick and with 12-18m an i does not lose fix anymore..
(and now i have working gps.. after 1 year of trying roms and waiting for better radio firmwares)
Click to expand...
Click to collapse
That's awesome! Could you please share a link to that item, please? I am really interested in that. I am still fighting with GPS. Sometimes it works, sometimes it don't...

[q] jiayu g4 gps

Hi everyone pretty new to the Chinese phones and apologies if this has been done before (i cant find it) but i have a JIAYU G4 youth which is running the latest custom rom off needrom.com (JY-G4 Yabe V7.0.2) this is the 3rd rom i have flashed and each one the GPS is very slow or does not work at all and you can not get a fix. The only way i can get it to pick up satalites is to use the engineer mode on mobille uncle tools which is quite long winded.
Ok so to my question "can the gps be improved by some sort of configuration?" I notice in the root of the sd card is a gps config file does this need altering somehow when used in UK?. Any help would be much appreciated as other than this it is a great phone.

The problem is rather the antenna in the back of the device when the device screen up and metallic body, the blocked antenna. GPS works well when the device display down.
But there are some guides on how to improve GPS software (according to me do not work):
http://gizbeat.com/2159/gizbeat-101-gps-not-working-on-mtk6589-mtk6577-mtk6575/
http://www.youtube.com/watch?v=ZnY_425NgB0

This is more than only a hardware (antenna) problem. I've noticed that when I connect an external BT mouse that the mouse itselfs gets a "spot on" fix, but the phone is struggling to keep this fix.
By editing the build.prop and disable JIT the phone has a much better GPS fix.

GPS fix issue in Jiayu G4
Finally the issue is solved by 100%
The problem is rather the antenna in the back of the device .
The PCB has contacts for GPS antenna , the 1st & 3rd are the ground & the middle i.e 2nd is the main antenna.
I just skipped 1 & 3 contact by putting insulating tape between contact & the antenna.
Only 2nd point is touching the antenna .
just that's all.
Now my phone fixes GPS with in a minute in cold start.
I tried with most of the available ROM.
Pls note : If you are not a technical person do not open.
refer to some mobile repair person .
soon release the photos of the same.

Re:Finally the issue is solved by 100%
pankaj459 said:
Finally the issue is solved by 100%
The problem is rather the antenna in the back of the device .
The PCB has contacts for GPS antenna , the 1st & 3rd are the ground & the middle i.e 2nd is the main antenna.
I just skipped 1 & 3 contact by putting insulating tape between contact & the antenna.
Only 2nd point is touching the antenna .
just that's all.
Now my phone fixes GPS with in a minute in cold start.
I tried with most of the available ROM.
Pls note : If you are not a technical person do not open.
refer to some mobile repair person .
soon release the photos of the same.
Click to expand...
Click to collapse
Hi Pankaj459,
I tried the software fixes, which got me a quicker fix. Unfortunately the fix is not very accurate.
Very often the GPS loses its way and I find myself about 100yards beside the road or in a nearby street.
I opened up my G4A and noticed that the 3rd pole had already been isolated with black tape. I did also isolate the left pole. Nevertheless, did not see any difference.
The fix took just as long/ short. Accuracy was just as dismal.
Is there anything else I can do? Would it actually help if I modded some copper wire to the GPS contacts, or would that not solve the issue?
Thanks in advance for your help.
Litening

for those who can speak german (like me) here's a link to my gps antenna project
h ttp://w ww.android-hilfe.de/jiayu-g4-forum/441446-jiayu-g4-gps-20.html#post7161636

litening said:
Hi Pankaj459,
I tried the software fixes, which got me a quicker fix. Unfortunately the fix is not very accurate.
Very often the GPS loses its way and I find myself about 100yards beside the road or in a nearby street.
I opened up my G4A and noticed that the 3rd pole had already been isolated with black tape. I did also isolate the left pole. Nevertheless, did not see any difference.
The fix took just as long/ short. Accuracy was just as dismal.
Is there anything else I can do? Would it actually help if I modded some copper wire to the GPS contacts, or would that not solve the issue?
Thanks in advance for your help.
Litening
Click to expand...
Click to collapse
So do you think the solution has to do with putting aluminium paper in the antenna? I have seen that fix in THL and it seems to fix the accuracy, maybe it is the solution.
Would anybody share a little tutorial on how to do it?

ertioct said:
So do you think the solution has to do with putting aluminium paper in the antenna? I have seen that fix in THL and it seems to fix the accuracy, maybe it is the solution.
Would anybody share a little tutorial on how to do it?
Click to expand...
Click to collapse
Hi
You should try to follow this step by step tutorial about configuring GPS + antenna mod , it reaches up to two meters accuracy in motion in a Jiayu G4T :victory: :victory:
A version in Spanish is available as well --> Versión en español :highfive:

Need help with bad GPS

I have early batch with bad GPS.
I could improve the signal strength and it's accuracy by slipping a piece of paper underneath the gps sensor as shown by many videos instructions on YouTube.
But after sometime, it would be bad again and need readjustment.
So, I am thinking to replace the back cover to fix this issue permanently.
Would this be the solution?
Anyone has done this before?
Thanks

I am currently having this issue as well. The folded paper underneath the pins did not help so I am wondering as well if changing the back cover will help.
Thanks

gogol said:
I have early batch with bad GPS.
I could improve the signal strength and it's accuracy by slipping a piece of paper underneath the gps sensor as shown by many videos instructions on YouTube.
But after sometime, it would be bad again and need readjustment.
So, I am thinking to replace the back cover to fix this issue permanently.
Would this be the solution?
Anyone has done this before?
Thanks
Click to expand...
Click to collapse
Did you try putting electrical tape like shown in one of the videos?

darkgoon3r96 said:
Did you try putting electrical tape like shown in one of the videos?
Click to expand...
Click to collapse
Electrical tape? No. I have never seen that kind of specific.
I only put a piece of paper underneath the GPS sensor.
By the way, I bought the back cover replacement, it doesn't help. So don't bother.

provider maybe
i have a first day nexus gps (tmobile) is excellent. had 3 phones with sprint gps previously,sprint gps sucked donkey ****.

My N5 had a bad GPS. It was incredibly frustrating tyring to navigate anywhere. I called Google customer service. They went through some trouble shooting formalities and my phone was found to be defective. They had me put my N5 in safe mode and activate 'GPS only'. I wasn't surprised that my phone never found a signal. The replacement phone works perfectly. Signal locks are fast and navigation is spot on. Basically it's how you'd want your GPS to work. So if i were you. I'd get it replaced.

kresk said:
My N5 had a bad GPS. It was incredibly frustrating tyring to navigate anywhere. I called Google customer service. They went through some trouble shooting formalities and my phone was found to be defective. They had me put my N5 in safe mode and activate 'GPS only'. I wasn't surprised that my phone never found a signal. The replacement phone works perfectly. Signal locks are fast and navigation is spot on. Basically it's how you'd want your GPS to work. So if i were you. I'd get it replaced.
Click to expand...
Click to collapse
Yeah that's true. This is only related to first batch. I should exchange it, but it's to late now for warranty. But I am going to buy nexus 6 ?