How can I build a simple radio-controlled device locator?

[coderlen]

I want to develop a device to locate equipment within my house. This doesn't need to be anything sophisticated, like GPS or GSM. The base station just needs to be able to page the equipment, and sound a beep and/or turn on a light on the equipment. The range does not have to be very far, say, 150 to 200 feet.

Hopefully this can be done relatively inexpensively with existing technologies. I envision using garage door opener technology, but without any motors having to be activated. I think that I would have a base station plugged into a 110-volt A/C outlet, and a battery-operated speaker and light on the equipment to be located.

It would be nice if 2 or more devices could be located, separately, perhaps with different radio frequencies, from the base station. And maybe the frequency could be different for each device, maybe with single side-band or some other way to distinguish between the devices.

Eventually I would like to have the actuator become a thin piece of adhesive tape, with the receiver, speaker, light and battery built into the tape.

I would appreciate links to places which have the microchips and transmitters ready to purchase, which can be assembled as one combined unit. If that is not possible, then I would need help in designing micro circuits for the project. I have a computer background, both hardware and software, so I feel I could handle the programming, but I don't have radio or microcoding experience. So any general help you can provide would be appreciated.

This is a small project, one which I think I would have a lot of fun completing. But I just don't know where to start. Thanks for your help.

 

[Analog]

I want to develop a device to locate equipment within my house. This doesn't need to be anything sophisticated, like GPS or GSM. The base station just needs to be able to page the equipment, and sound a beep and/or turn on a light on the equipment. The range does not have to be very far, say, 150 to 200 feet.

Hopefully this can be done relatively inexpensively with existing technologies. I envision using garage door opener technology, but without any motors having to be activated. I think that I would have a base station plugged into a 110-volt A/C outlet, and a battery-operated speaker and light on the equipment to be located.

It would be nice if 2 or more devices could be located, separately, perhaps with different radio frequencies, from the base station. And maybe the frequency could be different for each device, maybe with single side-band or some other way to distinguish between the devices.

Eventually I would like to have the actuator become a thin piece of adhesive tape, with the receiver, speaker, light and battery built into the tape.

I would appreciate links to places which have the microchips and transmitters ready to purchase, which can be assembled as one combined unit. If that is not possible, then I would need help in designing micro circuits for the project. I have a computer background, both hardware and software, so I feel I could handle the programming, but I don't have radio or microcoding experience. So any general help you can provide would be appreciated.

This is a small project, one which I think I would have a lot of fun completing. But I just don't know where to start. Thanks for your help.

Sounds like several Senior Level Design projects I've seen over the last few years. This has been done before, using RFID technology. The RFID tags are like a piece of tape with a printed antenna and a small microchip embedded in it that has some information on the device etc. The RFID reader sends out a signal to query the devices in range. The tag would then have to either report back, or do something else. There are some specific problems you must address:

1. The RFID tags are inherently powered by the RF field generated by the reader. This is a feeble energy source, and would not be able to power a "beeper". You would need some other energy source like a battery. If this is on your tape, then it will only be good for the time the battery lasts.

2. The RFID reader is generally good within a few feet of the tags, so the 150 to 200 feet thing is out of the question, you would need a fairly large generating source to do that.

Otherwise, it would be pretty straight forward.

 

[Sig239]

My television remote has this feature built in. It is similar to what you (coderlen) describe (Garage door opener). When the feature is enabled, an RF receiver in the remote is always on, listening for the "Where in the f**k is the remote" signal. Always on=lots of dead batteries. I've only used it twice....and if I didn't have the feature, I would've looked a little harder and found it anyways.
Actually, most cordless phones have the ability to be paged from the base, and some can even use multiple handsets...sounds like it is right up your alley...but then again, you said you wanted to develop it.

good luck, and keep us posted

 

[audioguru]

I envision your house is jam-packed full of junk and papers from floor to ceiling in every room.

No wonder you need an electronic device to find things.

 

[coderlen]

Analog, thanks for your post, and the information. I'd like to hear more about these RFID tags. Where can I get them? It would be OK to just have them respond within a few feet. Actually, having them remotely powered by the base station, or a handheld base station, would be OK. When I am searching for the device, I would be looking all over the house for it, going into every room, until I see it. I assume that the RFID tags would light up when I come close, right? Would the tags and reader be inexpensive? Please tell me more.

Sig239, I have used the cordless phone's finder to find a lost handset. I like it, and I want to get my hands on something that can be attached to other pieces of equipment which don't have this technology. I don't necessarily want to develop it myself, why reinvent the wheel? But I don't want to have to buy a new cellphone for each device, you know what I mean? It has to be cost-effective. So I need something which can be lifted out and placed inexpensively on the devices. Tell me more. Thanks.

audioguru, thou cuttest me to the quick! My house is, at times, a mess. But I think we all at times have been frustrated with finding things that are lost. I have even lost the cats, and it would be reassuring to be able to locate them, when they are sleeping in an unusual place, like in a closet.

Anyway, it sounds like a fun project. But I need the specifics on what type of electronics to purchase, and where to get it. Thanks a lot for your help.