Ublox Dead Reckoning GPS

jcdillin · 01-09-2006, 07:27 AM

Well finally after way too long i've finished my dead reckoning set up.

The old thread that laidback did with his module is here. But I figured it was time for me to get my own thread.

But the project in a nutshell is that Ublox makes a dead reckoning module, but the problem is that it needs a carrier board to hold the TTL to RS-232 converter, backup battery and gyro. So I created one.

Also for those of you that want to know what dead reckoning is, basically by using speed pulses from your car and the onboard gyro, the GPS module can guess where you are going, so if you are driving around in a big city with lots of tall buildings, even if you lose GPS signal the module will still output your current speed and position. Yes it may not be as accurate, but will be much better than your position just stopping on the map where you lost signal.

I still need to install the module into a case and get it wired into the car. But so far as is good with it.

On to the pictures!

As you can see the carrier board is not much bigger than the module itself.

Also if anyone wants schematics and PCB layouts for the daughterboard they are more than welcome to them, just shoot me a PM.

meddler · 01-09-2006, 07:32 AM

very cool. how much did it cost all up?

jcdillin · 01-09-2006, 08:39 AM

$330 roughly.

Scouse Monkey · 01-09-2006, 08:46 AM

does it work?

jcdillin · 01-09-2006, 10:30 AM

nope it's just for looks.

it works as far as navigation goes, gonna test the DR portion of it tomorrow.

Scouse Monkey · 01-09-2006, 10:46 AM

cool. i expect detailled maps like uBlox and Tyco produce!

Scouse Monkey · 01-09-2006, 10:49 AM

nah seriously, what about using a GPS logger and run a normal GPS reciever and the ublox. Do the journey a couple of times with the antenna on the ublox out in the open and then under something and then compare the coordinates at various points. Might be a bit too much work so maybe put some ASCII or delimited files on here for people to do the post processing for you. Can also use that software, forgotten what it was called, yo play back the log file into the GPS software for visual comparison.

jcdillin · 01-09-2006, 01:02 PM

actually with the U-center software that ublox makes I can load a image into it and it will trace my route into that image, so then I can just compare the two routes. For the most part I just need to drive and then disconnect the antenna, I should continue on the same path I was on regardless of a turn or not.

Scouse Monkey · 01-09-2006, 01:08 PM

coolage

0l33l · 01-09-2006, 06:46 PM

Why does it have two serial ports

cherrybomb · 01-09-2006, 06:52 PM

Convenience.

You only need one, just like a standard GPS unit. But a second is provided, just in case you want to feed it into two apps, without using.. Er.. Whatever that port replicator software is called.

jc, correct me if I'm wrong.

jcdillin · 01-09-2006, 07:05 PM

exactly.

Quattro · 01-09-2006, 11:53 PM

$300???

You gonna give me a deal on it?

Naamanf · 01-10-2006, 12:40 AM

I would wait till the new more sensitive GPS receivers become available.

0l33l · 01-10-2006, 12:41 AM

How does the Ublox compare to the SirfIII besides the DR?