Tracking a Device

Many supermarket trollies are fitted with devices that prevent the passage of the trolley beyond the supermarket's perimeter with a view to preventing these from being an environmental nuisance...

oh .. i didnt think of it ... but do you know what technology are they using for such .... i think its rfid !!

http://www.growthcompany.co.uk/companies/articles/rns/474556/product-launch.thtml

that´s interesting ... more in the lines of what i am looking for ... do you know how much it would cost for a rfid reader and the chip.

Also in my application its going to be at a very small level ie detecting just one device ... so i wonder if there are more cheaper or any other ways also to do it

Prices may be obtained from the supplier and competitors.

I think this is what you're looking for. No idea if it's cheaper than what you can build from scratch with RFIDs. Main function is as a finder but it also has an out-of-range alert function.

http://www.loc8tor.com/

In case I want to build a simple one ... what are the requirements for it ? I have no idea about rfids :(

Nor have I. I was simply pointing out an off-the-shelf device that seems to do what you want: I have no special knowledge of its technology. If you want to build your own device then I'm not your man.

Hellow!!

Here is needed more information.

1. How many devices are you going to monitor?

2. Are they into metal containers?

3. Are they made from Metal?

4. Do you want to locate them with one meter range or just to know when they went out?

As much information I have I can help you better.

For you Information:

1. RF waves do not work properly close to Metals.

2. To locate a device into specific place it is needed more than two antennas for reference.

Saludos!

Delmar

hi,

i am monitoring just one device. and want to locate them just when they went out about maybe about a couple of meter range. And no metal is going to be used.

I was wondering also if there could be cheaper ways of doing it ... but i think rfid could be the only solution i could think of.

Buy an electric dog collar. When the dog gets out of range (adj.) he gets zapped. One of those bad larry's would work quite well in your application.

I am wondering if there are any alternative solutions for this. Because I am thinking an Rfid solution could be expensive and also that the tag is too big. Also I dont want to use different batteries one for the device and the other for the tag. So have to find a way to integrate them together.

RFID is good, as long as the device has to pass through the activator equipment on its way out, you know those panels at the doorways of shops.....

I am just looking at the alert mode of operation. ie when a device like a key, or something else is taken out of a room it should be indicated with an alarm.

Then, as I said before, RFID would appear to be the perfect solution for you - as long as you don't have people who are trying to steal objects and also know about the RFID stickers and who would remove them first!! Thats exactly how store thieves try and work.

If that is the case, then you need to also have full video coverage ( with video tape somewhere else!) of the storage room in question as well to be able to know when and who removed the RFID sticker.....etc etc.

As you have not given us really much detail (squeezing blood out of a stone might be easier than getting full details from you!), I cannot be sure that my answers are going to help you much!

If my latest comments are in any way unhelpfull, then please be so kind as to tell us the complete story in your next reply. Thanks in advance.

This is one of the ideas i am thinking of. There are these last pointers used in the presentations. I want to find a way by which the person doesnt accidentally take it along with him. So when he goes out of the room with the pointer , the alarm should indicate this.

I guess the people concerned are not so depraved as to peel off the RFID sticker (they stick very well onto clean plastic, clean with methylated spirits) in front of the class so to say......

The costs of an RFID activator will have to be investigated first though......it might be much more than the Laser (last??) pointers......so a long cord might be cheaper and better!!

Or put a huge piece of wood (say 1/8" ply of 12" x 12") attached to the pointer with a yard of fine but strong cord and weld the knots with hot glue! Put a message on the wood like : "Please leave me here when you leave, thanks"

Thanks for the suggestions. But I was thinking of integrating some technology where the user doesnt have to go through all the hassles .... I cant think out another technology other than rfid for this case. Do you know if there are any products out there which do similar work.