Project: Multi GPS Tracker

Could be fun for those high tech larps :slight_smile:

This project started some time ago, (early 2008?) but is finally here.

As the name implies it can track multiple GPS units.

The tricky bit was the software.
There are some off the shelf products aimed at fleet management.
I tried to get some going but gave up.
The best candidate ran on linux but my kungfu is not strong there.

So after learning VB6, I wrote my own.
It’s pretty no frills at the moment.

-The test site
http://maps.google.co.nz/maps?ll=-36.815914,174.643008&spn=0.002358,0.003954&t=k&z=18

Data

View from point D > C

View from point C > B

View from point B > A

A from the clear

At the base station

-Review
You can see me driving into the park.
I walk all 3 with me until IO loose the signal and then place the Red unti there.
I then walk around the bush to check signal, no loss.
Down the hill until I loose it near the bottom.
Place the yellow unit.
Down a path, don’t get far until I loose it.
Understandable once you see the picture.

The Red unit drifts quite a bit after placement as you can see by the clump of red around it.
Looks like about ±5m.
I forgot to take a pic of placement, it was in a tree, sideways.
So the gps antenna was not pointing up.

The Yellow not so much but probably more due to the fact it was not there long.
5 mins at most.
The Red was there for 13 mins?

-Hardware

A MediaTek MT3329 based module
http://www.quadroufo.com/product_info.php?products_id=68&osCsid=30f5671f821443f0877ab545feea6c3f

PAN4561 wireless module, loaded with Synapse Meshing firmware.
Each radio can repeat the signal until it gets to the destination.
The test from A to D would be 3 hops.
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=P14236CT-ND
http://www.synapse-wireless.com/

How small could it be made?

Comes down to how long you want it to run.
It draws about 3.3v 180mA.
The battery pictured will run it for 6 hrs.
It is a 2s lipo pack which would be reconfigured to 1s2p

Cost?
The gps can be had as cheap as nz$40 per unit
$35 radio
$5 battery
$5? suitable case.

$85

On the base station side,
$35 radio
$10 USB > RS232 converter
$5? suitable case.

$50

-To do
Adjustable trail length
Smart updating, eg no extra markers if unit is not moving

Since the Radios are 2 way, we could add a screen and send each unit text messages.

Wicked! So you have GPS units plugged into hand held radios, that are sending position information back to the base station, which plots them on google maps in real time?

If you need a hand tidying up your VB6 code, I’ve done a lot of work in it. It wouldn’t be hard to plot some lines between those points for example…

Not handheld radios, radio modem modules.
A lot smaller :slight_smile:

Google maps would have been nice, maybe next version.
Just a plain image with scaling done by the program.

Might call on your VB skills there :wink:

A feature that could be geo fencing.
ie, if you get near an area the device could start beeping.
Or if another device comes near you.

Ready for field use. :slight_smile:

Changed radio modems.
Made hardware and app for android phones.

There is some cheaper gps’s on ebay at the moment.
$20 shipped :astonished:
And better modems out that what I am using, so for the same power, better range.

-

A few little bugs to work out but definitely usable now.
Field tested Saturday.

Happy to loan out to a GM so you can keep track of those crew everywhere. :slight_smile:

You are amazing. You probably knew that already, I was just offering a second opinion.

Wow, those are seriously cool. I wish I knew electronics sigh

Thanks guys.
It is always to get a second opinion, one thing to think you are crack, reassuring to know other people think it too :slight_smile:

This is seriously cool gear. There is some real potential for sim groups and larpers… any recreational activity with teams of people that need tracking really. Sports such as cycling and mountainbiking could benefit as well. It could add a dimension to orienteering and treasure hunt type activities. Awesome.

Awesome. Masses of potential for tracking location of NPCs, PCs, largish items, etc.

If you were doing a big trek game where the player are in a party that travels a long distance and encounters stuff along the way, could you give them a transmitter and track their location so that the NPCs could get ahead of them accurately? I suppose range would be an issue, but you’d at least know when you were getting close to them. For long distance tracking you’d maybe need a GM with the players, calling the NPC GM on cell phone and giving the GPS location?

In thick bush they are good for 200m.
Strategically placed repeaters can greatly extend the range.
With a good view of the sky, GPS is accurate down to 1m.

That scenario could work.
Give the PC + NPC a tracker.
If you have spare android phones let the npc have one even, so they can see themselves the progress of the PCs.
Less GM management :slight_smile:

Note it is a full fledge data network so messages could be send on it no problem if cell phone coverage is a problem.
Which is is in most of the places we play.
Yet to be implemented.

Awsome Project :slight_smile:

I am currently working on a system that uses a prepaid cellphone interface to SMS a base unit with the location and once I have this sorted will swap out the cellphone unit for a sat modem as the project will be part of an autopilot system in an automated boat.

The core system is an Atmega processor and there are pleanty og code snipets out there to allow it to communitate with all sotrs of devices. One issue i ahve found is that if the GPS is not moving more than 8 knots the direction adn fix indicators start bouncing around and make a mess on the map.

Theer are also other short range communications devices about that I have looked at motly running on the 400 to 900Mhz mark as the lower the freqyuencey the further it goes however the more power required to drive it.

TO resove the direction issues i have been working on a compass module that has tilt compensation so as to be able to filter the pitch and roll of the vessle. I suspect the device could also be used to deal with the running of a person. what is really cool is these devices also have the ability to output inertia.

Regards
Andrew

Interesting project there Andrew :slight_smile:

Low cost IMUs are surprisingly accurate thanks to mass production in phones etc.

Do you have a project page or something?

My last fling into auto pilots started with the ArduPilot and ended with… lots of spare parts :stuck_out_tongue:
Learned a bit on the way so not all lost.

I dont have a project page as yet but am working on it.
I have the arduinopilot megga and it seems prety stable. tried the standard arduinopilot and found that there were not enough I/O’s for me unless i added a sheild.

I really cant wait to get this in to the water…

Andrew

I saw these in use at Teonn. Is there a chance that we can get a set for Wellington for the inevitable increase in the number of campaign games that will happen over the next few years?

Sure, how many were you after?

Or I could loan them when required.

[quote=“mr_westie”]Sure, how many were you after?

Or I could loan them when required.[/quote]

I wouldn’t want to compete with Auckland campaigns for their use. I’m not sure how many I’d need at this stage. How many have you made and successfully used at Teonn?

The largest deployment I have had is 14 trackers, 3 team leader units, 5 repeaters.

How large was the area that you used that largest deployment in?

1.5x1.5km

Although at Moto moana due to terrain and bush density, 5 repeaters was just enough to cover the bush area.