So, I wanted to get a tracking device. As soon as I looked into the market, I realized the prices for one of those things begins at an arm, and goes up to a leg or more! The madness must be stopped! Surely the principles of knowing where something is could be used without paying out the nose for it. After some hair pulling, this idea was born. This took a lot of trial and error before I was able to hammer out what it has become for me today, and for all that, it is just workable enough for my purposes. Therefore, if you can think of a way this concept could be made better, please share! I've built on the shoulders of giants, and I expect you to do the same. This idea belongs to the people! Information is free! Insert an inspiring slogan here!
The nature of this tracking device is extremely limited and technical, but if you can hack it, this really works -- and that in itself is really exciting. The limitations are at times frustrating:
To quote, with a slight change, someone who inspired me to think this way: "If you can't modify it, you don't own it!"
Building on that, the lesson I have learned and hope to teach others is that something's label should not limit the way we use it.
The nature of this tracking device is extremely limited and technical, but if you can hack it, this really works -- and that in itself is really exciting. The limitations are at times frustrating:
- The 2-way radios necessitate a linear or nearly linear sight on your tracking device (which in many cases may spoil the whole point anyway).
- You must be closer to the transmitter than the nominal range of your radios.
- The tracker can get bulky (think about it -- you're basically lashing together two electronic devices that were originally meant to work separately).
- This one is the worst limitation: you will need to be able to manually sift through the static garbage that radios usually emit to find the data your GPS is trying to send. If you are a total 1337 h4ck3r, you may be able to write a program that pulls it out automatically and feeds it into Google Earth. (If, incidentally, you do accomplish this, tell me what to do to gain your favor when you take over the world.) Beware! Radio static can get really random, and will even imitate the data you are after, often giving you misleading results.
To quote, with a slight change, someone who inspired me to think this way: "If you can't modify it, you don't own it!"
Building on that, the lesson I have learned and hope to teach others is that something's label should not limit the way we use it.
Remove these ads by
Signing UpStep 1: Gather Supplies, Tools, and Materials
Get a GPS that you can plug into a computer. I used a Garmin GPS 72. I am of the opinion that Garmins are the best and most reliable, as well as the easiest to hack. If you insist on using a different kind, be prepared to figure out the I/O stuff yourself. At any rate, I suppose this project is possible with any sort of GPS unit, provided it can send info at a low baud rate.
Get a cable that connects the GPS to a computer. For my project, I used a COM port plug, since I already had it lying around, but I suspect using a USB connector would have been slightly easier.
Get a pair of walkie-talkies (Americanese for 2-way radios) that have an impressive range. For this example, I am using a pair that boasts a 12-mile range.
Other materials included in this project: Wire, solder, batteries, a computer, and glue or epoxy. Optional: something to track.
Tools you will use include: wire cutters, wire strippers, screwdrivers, pliers, a soldering iron, a DMM (Digital Multi-Meter), scissors, an undefiled radio, and the user manual of your GPS.
Find a quiet, peaceful place to fine-tune this. Several of the steps are bound to be frustrating for a first-timer, as they were to me.
Get a cable that connects the GPS to a computer. For my project, I used a COM port plug, since I already had it lying around, but I suspect using a USB connector would have been slightly easier.
Get a pair of walkie-talkies (Americanese for 2-way radios) that have an impressive range. For this example, I am using a pair that boasts a 12-mile range.
Other materials included in this project: Wire, solder, batteries, a computer, and glue or epoxy. Optional: something to track.
Tools you will use include: wire cutters, wire strippers, screwdrivers, pliers, a soldering iron, a DMM (Digital Multi-Meter), scissors, an undefiled radio, and the user manual of your GPS.
Find a quiet, peaceful place to fine-tune this. Several of the steps are bound to be frustrating for a first-timer, as they were to me.
Visit Our Store »
Go Pro Today »
You could improve your transmission rate immensely by placing a couple simple intermediary devices in the circuit. Your radio's are meant to transmit audio not pulses like come out of the GPS and go into the computer. It is shear luck that the computer interprets the spikes/clicks coming from the receiver to the computer. There are a couple of replies that point to the Automatic Packet reporting system which would work and solve a lot of your problems.
This is best way to implement your solution, not using cell phones. Use Dual Tone Multiple Frequency transmission (DTMF) it marries the Serial Digital Data from the GPS to the analog audio transmitted and received and converts it back to Digital to interface to the computer. Follow the links to a device, one of many, that perform this task.
http://www.cmlmicro.com/Products/index.asp?/Products/WTelecom/CMX865A.htm&searchvalue=wlt&setindex=1&gclid=CMa965GWqKkCFcsZQgodvCDpLg
God bless Yankee ingenuity !!!
thanks>
As for broadcasting, especially AM band, it shouldn't be illegal if you're using a blank channel and a friend who has a license. Most truck drivers have a CB radio license, which is sufficient for AM broadcasting. I'm not sure how that would improve the signal, but if you try it and the signal is improved, definitely please let me know.
If there was a cheaper and easier way to make a tracking device, I would love to hear about it. But as far as I know, this is the epitome of cheap and easy in the world of tracking devices. As such (cheap and easy), the reliability could use a little work, in my opinion. I hope someone improves on it to where the data can be automatically interpreted by the laptop instead of having to cull over the raw data with your own eyes. That would make this easier!
It is called the Automatic Packet Reporting System
http://aprs.org/
"Hey Bubblegummer, where am I?"
"Uh... At your house."
"That's right! Wow, this system actually works!"
"Heh."
"Okay, now where am I?"
"Uh... At your house."
"This is SO AWESOME!!!!!!!1"
<http://en.wikipedia.org/wiki/Automatic_Packet_Reporting_System#Technical_Information>
In its most widely used form, APRS is transported over the AX.25 protocol using 1200 baud Bell 202 audio frequency-shift keying(AFSK) on frequencies located within the amateur 2-meter band.
David