New to electronics with a project idea

[Bluedreamer]

Hi All, first post.

I have an idea for a hobby type project that I wish to build, but since I have little knowledge of electronics, I am lost on how to start - what I need etc.

The project idea is simple. I want to build a portable handheld device that shows direction and distance of a small transmitter.

The idea comes from me an my gf getting sick of trying to find each other in those big super stores when we go.

So each would have a little "tracking bug" type item and a little receiver with an lcd screen that points at the other tracking bug and gives distance. Maybe also the tracker could be built into the display unit.

I would guess the maximum distance it would need to work would be about 600-700ft (200-250m). ie The furtherest you could be away from each other in one of those huge Wal-mart/Target type places.

I have seen lots of FM transmitters and receivers but don’t know if these would work or even be able to transmit / receive at that distance.

1. So is this a reasonable possibility for me to build something like this?
2. How much would it cost?
3. Is there a better way to do this?
4. Is it legal to transmit radio like this in the USA

Thanks for your time


Adrian

 

[Brevor]

Building something like you describe would be very difficult for a beginner, or even a professional for that matter. If something like this would be inexpensive to make I am sure they would already be on the market.

 

[jbeng]

Instead of trying to track using radio signal strength, etc., design a device that can determine it's own position (like a sort of GPS). Then, it could transmit it's location data to the other unit(s) digitally. GPS itself may have the accuracy/resolution you need. You might have problems with the GPS receiver being shielded from the satellites' signals by the metal structure of the building, though. I don't really know much about the current generation of GPS, however.
Jeff

 

[Papabravo]

You could just pass a simple multiple choice test, get an amateur radio license, and use a 2M handheld to exchange much more than position. A set of FRS walkie talkies might also work for you. No license or test is required.

 

[mneary]

You could use one of those 120db emergency screamers (audio) and let your friend locate you (once your hearing recovers...)

oh, probably not legal. Definitely inconsiderate.

 

[Andy1845c]

The idea comes from me an my gf getting sick of trying to find each other in those big super stores when we go.

Your supposed to stick with the g/f.... even when they spend forever looking at pants and shoes...... Trust me..... I know these things

 

[audioguru]

Your supposed to stick with the g/f

Don't get too close to your g/f in a big store or she will catch you looking at all the other girls.

 

[bananasiong]

Don't get too close to your g/f in a big store or she will catch you looking at all the other girls.

You can still do it if you are skillful , walk behind her

 

[HarveyH42]

How about holding the purse while they go try something on...

 

[TrevorP]

You can still do it if you are skillful , walk behind her

Sunglasses.

 

[stevez]

You may find what you need in amateur radio publications. A bit of detail -

A. Foxhunting is one of numerous Radio Direction Finding activities that are part of amateur radio. The amateur license helps you deal with the licensing of the transmitter.

B. APRS - Automatic Position Reporting System is part of amateur radio. In one arrangement a base station with a computer transmits a query to a station - which is another transceiver equipped with some intelligence as well as a GPS. The remote, presumably mobile/portable station responds with the GPS position and possibly other information.

 

[Leftyretro]

That is not a trival application as others have already stated. Direction detection is somewhat simpler but distance is a real challenge. GPS is the only pratical way I can think of and this would not be a cheap or easy project for either the sending unit or receiving unit.

Lefty

 

[audioguru]

Sunglasses.

Then the other girls can't see you winking at them.

 

[jbeng]

Here's a GPS module from Parallax, about $70US. The text says that it's good for outdoors, so it may not work too well inside. Also, Navsync seems to have some interesting products.
Jeff