How to build a sensor that senses RFIDs?

[Adelle Lin]

Hi,

I'm a bit of a beginner at Arduino - i.e. have just soldered my
Freeduino board and am looking to begin on my first project - "lost
and found"

I'd like to build a device that helps you keep track of your personal
objects (I lost stuff all the time). I haven't worked out the
specifics yet but I'd broadly like to build a central device that
senses objects such as a phone, or hat, or keys (maybe using an RFID
tag?) within a certain distance that will flash a light of make a
buzzer sound if something leaves that perimeter.

If any body has ideas on what specific sensors and RFIDs I require to
get started that would be really really appreciated!

Thanks,
Adelle

[mixi plizik]

Fyi, check out this link you may get some ideas

http://www.engadget.com/2011/12/08/zomm-wireless-leash-plus-speaks-up-for-a
bandoned-iphones-video/

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[Carlos Chiossone]

Hi all, any good recommendation where to fix a Sharp TV? maybe a little off topic but you guys always have good answers.

Thanks,
Carlos

[Foxx D'Gamma]

If you like toss me an e-mail off-list and I can try to help you out. I am not an expert TV repair tech but I know how to diagnose common issues and find faults using basics EE tools.

~ Foxx

[Adelle Lin]

Yes, that's exactly what I want to try to build but being able to tag any number of items using RFIDs, any ideas what sensors and tags I need to get started?

Thanks,

Adelle

[derek enos]

This ZOMM is a powered device that communicates with the phone via a Bluetooth transceiver.  It likely uses signal strength or link status information to determine whether it's within range of the phone.

There are a number of low-cost RF transceivers that you could use to construct a similar system that tracks multiple items but, like the zomm which contains a rechargeable battery, it would require that each sensor be powered.

I have little experience with RFID but suspect that its effective range using passive sensors may be insufficient for your application.

Derek

[Adelle Lin]

Hmm.. thanks Derek, so you think an arduino sensor + RF combo might not be enough for a short distance system?

[Paul Strohmeier]

you can definitivly create you own sensors and just hook them up to an arduino. i remember seeing some kind of tutorial on how to build them. you may want to try google....

- sent from android device -

[derek enos]

I definitely believe that Arduino + RF can work for your application; it's RFID that I'm not certain about.

This powerpoint looks to provide a nice overview of passive RFID.  Since the sensors are powered over-the-air by the reading device, this type of system requires that the sensors be within the reader's operating range.  For example, this USB RFID Reader from Sparkfun apparently requires that the RFID tag be within 5-15cm (though user comments claim closer to 3cm) of the reader to function.  This one claims a range of 4.5".  Here's a Sparkfun video comparing their different RFID options.

[Dallas Taylor]

I am not sure if this is relevant but I came across the OpenBeacon Active RFID Project earlier today

http://www.openbeacon.org/

I heard it mentioned in the "Design of a Wireless EMG" talk at lasts years The Next Hope conference.

http://thenexthope.org/talks-list/

Dallas