GPS vehicle tracking, any advise ? - Page 3

Danceheaven · 07-04-2004, 08:03 AM

Quote: Originally Posted by Confused

Nope, the GPS software doesn't initialise the hardware, it just blindly reads (how it reads if it's blind I don't know, but it does for the purpose of this hilarious post

) the NMEA stream that's being sent to the serial port by the GPS.

So yes, in theory, you should be able to see in (almost) real-time where the car is, it depends on how quickly you can send the stream through the phone

Garry

Aha so garry u say ur name is you must be one of those smart arse type of people

TommieG · 07-04-2004, 10:36 AM

have you guys seen this?

http://www.directions.ltd.uk/products.php?cat=2

Tom

Ricky327 · 07-04-2004, 11:30 AM

Quote: Originally Posted by Danceheaven

I was thinking last night, (Careful i here you say), ricky if your using fsk to encode the nmea data and transmit it via gsm then decode it with a pic then feed this is to the com port on your local machine or tracking laptop if this comm port was set up as the comm for the gps reciever and you run say a mappoint or destinator wouldnt this show live tracking as in a exact duplication of the gps screen in the vehicle if it was running? or will the gps app need to initialsie the gps mouse first somehow?

Yup thats correct, "confused" did answer for me already

I have been testing it with mappoint and mapsonic all seems working well. I can only transmit a sentence once every 1-3 seconds depending on how long a sentence is...this is due to the fact the baud rate is reduced to 300 when transmitting over the phone. Of course some info is discarded so its not an exact duplication of the sentences...but it is more than enough for following the thief. I know some tracker can only update once evey 30sec or so.

At the moment Im working on filtering the incomming sentences from the GPS so only the important one is processed such as :

$GPRMC,$GPGGA,$GPCSA,$PGGSV

The location update is once every 3 seconds (maximum rate for $GPRMC at 300 baud). Ill like to insert some other sentence from time to time such as the number of locked on satellite, speed and some other info.

Im still not happy with 3secs location update though, so I may try to push the FSK baudrate to 1200 if the mobile can still handle it. Ultimately Ill like a once every sec location update. If I can find a sentence compression/decompression or implement a routine for the PIC I may do so...we will see.
.
.
.
When you say you can communicate both ways through dtmf, how you planning to decode the tone at your end? I know a PIC can do it but it can be calculation intensive and wont have much processing power left to do other things. I have seen those dedicated dtmf decoder though

Ricky327 · 07-04-2004, 11:39 AM

have you guys seen this?

http://www.directions.ltd.uk/products.php?cat=2

Yup, theres plenty out there but its the fun of making one that keep us going. They do normally cost around £300-£600. But for a £5-£10 add on to an existing phone/gps thats as good you cant really go wrong.

trdcpu · 09-05-2004, 03:44 PM

http://www.sacbee.com/state_wire/sto...11542277c.html

if we have any future questions on this subject, we should email this guy.

Ricky327 · 09-05-2004, 04:02 PM

Quote: Originally Posted by trdcpu

http://www.sacbee.com/state_wire/sto...11542277c.html

if we have any future questions on this subject, we should email this guy.

Another GPS tracking application

FishCook · 09-05-2004, 04:15 PM

Quote: Originally Posted by TrdCpu

:if we have any future questions on this subject, we should email this guy.

Damn!! You beat me to that post! It sounds like the guy had it set up pretty good, web site and all. Now if the guy was real hardcore, he would have figured out a way to hardwire the power for the phone

"The woman learned how Gabrielyan was following her when she discovered him under her car trying to change the cell phone's battery, police said"

minghi · 03-11-2005, 12:47 AM

i cant believe that this thread died five months back after all the advances made and brilliant ideas shared. anyway. this seems to be a pretty decent deall, especially answer no 17.

its free. you only need to buy a nextel phone with some data plan. check answer 5.

http://www.accutracking.com/faqs.html

saxgod · 03-11-2005, 06:01 AM

I use Ham radio to track my car. I'll post some pics of the setup later..
You can track my car here:

http://aprs.saxgod.be/track.php?call=on4sax-9

For more info, google for APRS

minghi · 03-11-2005, 03:31 PM

Quote: Originally Posted by saxgod

I use Ham radio to track my car. I'll post some pics of the setup later..
You can track my car here:

http://aprs.saxgod.be/track.php?call=on4sax-9

For more info, google for APRS

awesome, i did 'google' it and got some extensive information. pictures of your setup would be awesome.

thank you

ddn · 03-11-2005, 03:50 PM

No offense, but you're all going about this the WRONG way.

APRS is the solution. All these other solutions are going to be complicated, unreliable, maybe expensive. APRS costs you $14 for a Technician amateur license and $90 for a Byonics PocketTracker.

No monthly fees like a cell service. There absolutely IS NOT a better way to do vehicle tracking than APRS.

dexy · 03-11-2005, 03:51 PM

Quote: Originally Posted by minghi

i anyway. this seems to be a pretty decent deall, especially answer no 17.
its free. you only need to buy a nextel phone with some data plan. check answer 5.
http://www.accutracking.com/faqs.html

Thats true, accutracking concept is good, if you have nextel phone/service. One can take advantage of the fact that nextel phones already have a gps receiver built in, that is accessible from the java software, as simple as getLongitude(), getLatitude() e.t.c You dont even parse through the raw data. Next, the phone(some of them) allows call initiation via software, it allows audio channeling/redirecting e.t.c, and lastly it has a serial port you can do other stuff with. so u pretty much have a full package, software platform, a cellular modem, a gps unit all in one. The problem, is that it has to be nextel.
The other features also include full sms, and http access too via software.

I played around with it a bit. pretty good costwise, the phones cost as low as $25 bucks for an i730 used on ebay.

dexy · 03-11-2005, 03:54 PM

For hardware GPS/data module combinations, here are some good companies with cheap cost, I bought a few from.

http://uk.azzurri.com/ (reseller)
http://www.falcom.de/ (really good variety)

Most of these are GSM, so to use them, you will need a gsm provider, I guess internationally, everything is really gsm. Oh also, you need the US spec GSM frequency, pretty much a tri-band modem to operate worldwide.