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Using RFID Tags Around the House?
Attacked-by-gremlins writes "I have a larger family and various items in the house (some tools, some pieces of clothing) 'travel' unexpectedly. We joke about gremlins doing that, but it's tiring never to be sure that I'll find an object where I left it two days ago. For the sheer hacking fun of it, I'm thinking of sticking RFID tags on some and trying to triangulate a position with several tranceivers placed in the house. Has anyone have any suggestions for this amateur 'Google Home'? Thanks."
Beats the heck out of everyone learning to be considerate of each others' property. What benefit would that have in real life? ~
Invenio via vel creo
There's some equipment out there with decent range, but it's usually quite expensive. My $50 do-it-all tranciever has a range of about 6 inches. With the lower frequency tags you get better range, but still I don't think I've seen trancievers with anywhere-in-the-house type range.
FreeBSD.org - The power to serve
Really. Most sub $100 readers have a range that can be measured in millimeters. To get something with about 3' or 4' of range for a single reader will cost four figures. I've done some fairly extensive testing with these readers, and it is possible to boost the range by adding external antennas (for more money). So I guess what I am saying is that what you are planning on doing is technically possible, but is not feasible for most peoples' "tinkering" budgets.
I don't know what your budget is like, but the readers can be pricey. The ones we use that are able to triangulate (2-D with two readers, 3-D with 3 readers) ran about $4k apiece. But, they would easily cover a standard sized home.
Of course, we had different needs than you, so there are probably considerably cheaper alternatives.
He's getting rather old, but he's a good mouse.
Now, where dd I put that RFID scanner?
I've had the same thought. From TV remotes to your spectacles, there are lot of things that bear some tracking. No reason why it can't be a commercial product.
Buy two hammers separately. Make sure they are identical. Make sure you also have two receipts.
Next time someone misplaces your stuff, use one hammer to break their hand. If the skin breaks and blood gets on the hammer, throw it in your neighbor's yard and find a way to plant the receipt over there.
When the police come to find you, explain that you found your spouse, kid, dog, whatever in a crazed state with broken fingers. They must be hallucinating because they are blaming you. Hey, look at that! Maybe your neighbor just went inside, and, oh my god, there's a bloody hammer right next to his birdbath! Well, case closed, officer.
You'll never have anything misplaced again.
.
Maybe they (or their competitors) have a smaller unit that would work.
___ I don't respond to Anonymous Cowards, and I Never Mod them UP.
I've not studied up on the technology in a while, however, won't the distance of any given object be really far from the RFID sensors in a standard sized room?
Also, what are your size constrictions?
http://www.loc8tor.com/
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Have a lot of money available. Tranceivers that can detect small tags in a house-sized area are very large and expensive. Further, you would need at least two, and probably three depending on the house.
It would be less cost and trouble to just buy triplicates (or more) of everything you commonly misplace.
Why fix it if it ain't borken? I have attached one of these puppies to the remote, dog food bowl, fish tank and the Roomba (just in case). In fact, the only thing I don't use it for is my keys.
He was selling some device that could tag and find things in the home. It was more like car-key radios than RFID with a longer range.
I haven't looked yet, but I'm pretty sure there's got to be some products out there that you attach the speaker/receiver to and then a remote that makes it beep. I know that some cordless house phones have that ability in case you misplace the phone. I've often wanted to put something similar on my remotes/keys/wallet/shoes/etc. Then you can have fun running around the house trying to find the sound.
many readers stashed around the house and go by lats read locations.
Getting a reader that can do a whole room will be many hundreds, if not thousands, of dollars.
The Kruger Dunning explains most post on
Well kids, I've just come back from the store. Had to buy a hammer for the 7th time this week. I'm afraid it medical experiments for the lot of you..
/. in regard to RFID.
Seriously, if they can't learn, I understand that chloroform does wonders. Probably reduce your food bill too..... just kidding... kind of
Your problem is a human problem that CANNOT be solved by technology. This has been discussed elsewhere on
Technology will never solve this problem for you unless you invest in the new Acme AC1000 Spanking Machine.
Support NYCountryLawyer RIAA vs People
Install a security camera in the friggin' hall. Then you'll see the "ghosts" moving your clothes and stuff around :)
Then, install cheap notebooks (or perhaps mini-audio recorders) next to the doors, so the next time anyone needs something, at least they'll give you a message. "Hey Frank, I need to borrow your ipod".
If that doesn't work, hire a family counselor to force you guys to START COMMUNICATING!!
Based on everything I have read (many Slashdot posts, rarely articles), the only person in your household who would implement a RFID tracking system for various objects would be your eldest son, granted that he has siblings. Also, there is a chance that your in-home child care provider would take interest in this. Why not ask them, and report back?
Have a garage sale, and get rid of everything you don't need.
If you're losing items in messy closets or bedrooms, then you probably need to clean up the clutter. That or you own way too many valuable possessions that may be stolen or permanently lost. Live simple.
I live in a small, energy-efficient home. I own exactly what I need and no more. I have a computer, a desk, a chair, books, an acoustic guitar, a bike, and a couch. And that's about it.
All of my cookware and utensils stay in the kitchen and never leave. Cleaning supplies stay in a closet. My toothbrush in the medicine cabinet.
I never lose a thing. Ever.
Instead of trying to triangulate a position, you might be able to put a receivers on doorways, and log to a network each RFID signal received. This way when you look up your hammer, you can tell which doorway it last passed.
You never expect irony, do you?
Want to be a professional wrestler? Visit www.iyfwrestling.com
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OK, what would it take to triangulate location within a 6" on a side cube? To within millimeter accuracy? We are currently using a multi-million dollar x-ray scanner to do this at low doses, and if this can be done for a few thousands of dollars, that would be big deal.
...are a true geek. I salute you.
Try UHF(ISM band 903-928 MHz) RFID Readers; they have better range than HF readers (13 MHz). Intel sells a single chip (R1000) demo kit you can take and hack. You may have difficulty with large metallic objects due to reflection. Also, stuff with high water (H2O) content may absorb too much power to reflect back. With UHF, you may expect 5+ meters (20 feet) under ideal condition. The tags may be expensive in small quantity. Try to "borrow" from a larger lot. Obviously, you have to get UHF tags for UHF readers; I am not aware of multimode readers/tags.
You can get either the $6500.00 each scanners or spend $13000 in the $50.00 scanners and put them all over the place.
simple is a central PC and scanners at every doorway 4 per doorway should do it. to cover both sides and high/low carrying. then simply query the last doorway that tag 4855432 passed by, now you have what room it is in.
This works great until someone get's wise and then carries it in the doorway blind spots or grabs things at random and makes doors detect the items then smuggle them past the sensors and put them back just to screw with you.
What you want is only possible with a HUGE amount of money. If you have a $20,000 budget I think you can do it.
Do not look at laser with remaining good eye.
what about putting low range readers on each doorway?
It seems most people here don't seem to understand active rfid vs. passive rfid.
Passive:
pro - Tags are extremely small, readers are cheap, tags are cheap
con - Range, non-existant
Active:
pro - Range
con - expensive tags, tags are large, tags are battery powered
-- botsex is {grep;touch;strip;unzip;head;mount}
It seems like only one hammer is needed for you scenario.
So, what's the second hammer for? A redundant array of independent hammers?
--
As others have mentioned the range for passive RFID detection is painfully short - to do what OP wants he needs active tags and readers.
A passive RFID tag is powered by the reader - hence its short range. An active tag carries its own power supply - like the toll booth speedpass tags.
Active tags run from about the size of a dime to about the size of a paperback book - in my job I deal with the paperback book-sized tags.
we see things not as as they are, but as we are.
-- anais nin
Looks like the idea has already been patented.
http://www.patentstorm.us/patents/7295132/description.html
Our obsession with making everything small leads directly to this problem. Smaller things get lost more easily.
They sell those giant-sized remote controls at Walgreens or your local random-crap-mart. Buy one, you'll never lose it again. It can't fall between the cushions of the couch because it's friggin huge. If the thing you don't want to lose doesn't come in giant-size, permanently attach it to something which is too large to lose but still portable. Gas stations have learned this lesson, that's why the bathroom key is attached to a huge plank.
To make it even easier, paint it something bright and garish.
It's rare that you're presented with a knob whose only two positions are Make History and Flee Your Glorious Destiny.
Some of the old RFID readers with a 4 foot range have strong warnings on them about RF exposure. It may be cheaper to occasionally replace lost tools instead of having to someday buy medicine to reduce chronic pain of your family.
Why not have a portable reader that you can carry around with you. When you enter the room, you can get a printout of all the stuff in the room. If the printout does not correspond with your organizational directives--that's what kids are for!
Microwave stuff I want to hide?
---- "Logoff! That cookie shit makes me nervous!" - A. Soprano
...because, and I'm serious, when one thinks of Google, one thinks of an amoral to evil enabler of totalitarian Police States.
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For this to be really useful, I think you need an RFID tag on every item in the home. First, construct a new home with a single entry point (you can add emergency exits for fire safety.) The front entry room will contain a computer and an RFID tagging device. Every single object that comes through the door gets tagged, named, photographed, and described in the computer system before it is allowed into the house.
It's a little work upfront, but think of the advantages. No time wasted organizing your possessions. No time wasted "tidying up." Nothing can ever be out of place, because nothing BELONGS anywhere. The mixing bowl might not be in the kitchen, but it's no trouble. Just search for it using any of the dozens of wall terminals installed around the house, and a series of flashing arrows will direct you right to your desired object.
At last we may discover where all the missing socks go after they're put in the dryer!
Forget your house, try scanning your garage to see what RFIDs the feds see when you drive over wires buried in certain roads.
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TOP SECRET FACT:Most modern cars have tracking transponders ALREADY!
Spy transmission chips embedded in tires that can be read REMOTELY while driving.
Yup. My brother works on them (since 2001).
The us gov T.R.E.A.D. act (which passed) made it illegal to sell new passenger cars lacking untamperable RFID in the tires allowing efficient scanning of moving cars.
Your tires have a passive coil with 64 to 128 bit serial number emitter in them! (AIAG B-11 ADC v3.0) . A particular frequency energizes it enough so that a receiver can read its little ROM. A ROM which in essence is your GUID for your TIRE. Multiple tires do not confuse the readers. Its almost identical to all "FastPass" "SpeedPass" technologies you see on gasoline keychain dongles and commuter windshield sticker-chips. The US gov has secretly started using these chips to track people.
Its kind of like FBI "Taggants" in fertilizer and "Taggants" in Gasoline and Bullets, and Blackpowder. But these car tire transponder Ids are meant to actively track and trace movement of your car.
Taggant chemical research papers
 http://www.wws.princeton.edu/cgi-bin/byteserv.prl/~ota/disk3/1980/8017/801705.PDF
(remove spaces in url from slashcode if needed)
The chips in your tires are for forensic "after the fact" database tracking, from databases collected on highway choke points, It can be done in real time too though.
I am not making this up. Melt down a high end Firestone, or Bridgestone tire and go through the bits near the rim (sometimes at base of tread) and you will locate the transmitter (similar to 'grain of rice' pet ids and Mobile SpeedPass, but not as high tech as the tollbooth based units). Sokymat LOGI 160, and Sokymat LOGI 120 transponder buttons are just SOME of the transponders found in modern high end car tires. The AIAG B-11 Tire tracking standard is now implemented for all 3rd party transponder manufactures [covered below].
It is allegedly for QA and to prevent fraud and "car theft", but the US Customs service uses it in Canada to detect people who swap license plates on cars when doing a transport of contraband on a mule vehicle that normally has not logged enough hours across the border. The customs service and FBI do not yet talk about this, and are starting using it soon.
A secret initiative exists to track all funnel-points on interstates and US borders for car tire ID transponders (RFID chips embedded in the tire).
The governement can then either look back in databases to see wheere and when your car drove, and OCR liscense plates at tool or Customs can
build the database up even better without the feds needing to visit your home to get your RFID GUIDs.
More sinister, it is near impossible to buy tires without the vendor in the USA filling out federal paperwork of what VIN the recipient car is!
Photos of tracking chips before molded deep into tires!
http://www.sokymat.com/index.php?id=94
PLEASE LOOK AT THAT LINK : Its the same shocking tire material I have been trying to tell people about since the spring of 2001 on slashdot.
a controversial dead older link was at http://www.sokymat.com/sp/applications/tireid.html
(slashdot ruins links, so you will have to remove the ASCII space it insertes usually into any of my urls to get to the shocking info and photos on the enbedded LOGI 160 chips that the us gov scans when you cross mexican and canadian borders.)
You never heard of it either because nobody moderates on slashdot anymore and this is probably +0 still. It has also never appeared in print before and is very secret.
Californias Fastpass is being upgraded to scan ALL responding car tires in future years upcoming. I-75 may get them next in rural funnel points in Ohio.
The photo of the secret high speed overpass prototype WAS at
http://www.tadiran-telematic
it would be more cost efficient to buy 10 of each item you keep losing. I keep a hairbrush chained to the bathroom counter with one of those bank pen-chain things (double length), I was sick of every single brush ending up not in the bathroom where I try to brush my hair. I wanted to do the same with the remote for the TV (chained to the couch), but have not yet.
As for tools, I buy cheap wrench sets whenever they are on sale, and I only break out the good wrenches after I have broken one of my cheapies. They are all stuck to the wall of the garage on kitchen knife magnet strips, so they are out of the reach of little fingers.
I will have to disagree this is solely a human problem. Technology can solve this. But it is not cheap. It is claimed that a better to give a rough location rather than to triangulate, which requires a subsequent mapping. Details can be found in K. K. Yap, V. Srinivasan, and M. Motani, MAX: Human-Centric Search of the Physical World, Proceedings of ACM Sensys 2005, San Diego, CA, USA, November 2005. Available at http://wine.dnsalias.org/motani/publications.php But the cost is quite forbiddingly now. I actually have a working prototype but it is nowhere near economical. Good luck and let me know if you can find passive cheap readers with the range needed (about 1m). Disclaimer: I authored this paper.
Whatever you do, *DON'T* put RFID tags on your socks.
They're missing for a reason. If you find them, a paradoxical black hole will open up in your dryer and engulf the entire planet. Trust me, I've done the math.
For the love of god... not the socks.
This sounds like the NASA joke of spending 1.5Million to write in space where as the USSR used a pencil.
http://www.snopes.com/business/genius/spacepen.asp
The cheap solution is to purchase some of these cheap tags and attach them to the objects in question;
http://www.nexusgadgets.com/Key-Finder-Key-Ring-pr-16448.html
http://www.cgets.com/item--Remote-Key-Finder--Single_Key_Locator
http://www.storepulls.com/products/Sonic_Key_Finder-218299-4432.html
That last one is under $2US.
So it's too expensive to buy the readers to do triangulation. But you could buy the cheap readers and put them on doorways to trace things as they pass by. Then you can track what room an object was last seen in. That is probably sufficient for your purposes.
I use a product called Homeseer and alot of people are already doing this. There are two types of tags people are using, iAutomate tags and cheaperRFID tags. The iAutomate tags are more complex, and hence more expensive. I have the Cheaper RFID tags. I have one in our laptops bags-- if no laptops are present-- no wifi. I don't believe they do triangulation. The iAutomate ones do- but are far more expensive-- at least when I last looked.
Most effective first step: clean up. Lost items are hard to see when they're mixed in with random clutter. Do whatever is necessary to get everything "put away"; more storage locations, less stuff, pick the stuff up and put it away. Imagine trying to find a pair of pliers in an empty room - now imagine trying to find the same pair of pliers in a child's bedroom.
Organization can help a lot too. Items that travel usually don't just make one hop. The sooner you notice they're gone, the easier it'll be to retrieve them. Things like a pegboard on the wall with the shapes of all the tools painted on it; sure, it might look a bit "anal" but it makes it very easy to glance at the wall and see that the pliers aren't there. You could use various organizational techniques to accomplish the same goal - the "win" here is that you can almost see things leave so you can easily find them - and notice that they're gone and start your search before you actually need the item. Much better to chase that adjustable wrench today rather than in three weeks when the water faucet springs a leak.
And communication is also a great tool - especially if there's children involved. Those "press to talk" cell phones are just about perfect for this. After the kids have been embarrassed by Dad asking about lost tools a few times they'll adjust their behavior.
And finally - put this stuff in its proper perspective. On the scale of big things in life; marriage, children, happiness - well, that lost hammer just isn't very important. Some may suggest that a person who is considering spending thousands of dollars to track his missing tools (that are worth maybe a hundred, tops) may have some "issues". Your mileage may vary...
Would this work for the socks that my dryer eats?
We lose things all the time, but find most of them, others are lost for good. So we have to compare the cost of RFID tags + RFID scanner, vs the value of the items permanently lost + the inconvenience of items temporarily lost.
"I'm thinking of sticking RFID tags on some and trying to triangulate a position with several tranceivers placed in the house. (Does) anyone have any suggestions(?)"
When you have people over for a dinner party, turn off the speaker that says "PLEASE RETURN TO THE STORE!"
Three Squirrels
All my belongings used to fit into a large duffel bag, and I would still loose things just as often. It is more about people not putting things back when they are done using them (or having a very loose definition of when they are done using them) then it is about clutter.
The best answer was given already. http://www.loc8tor.com/ [loc8tor.com] http://www.loc8tor.com/ [loc8tor.com] http://www.loc8tor.com/ [loc8tor.com] This directional handheld device costs less than $100 and comes with some tags to get you started.
1. Collect Attacked-by-gremlins' stuff
2. ???
3. Profit!
Sparkfun has a nice RFID reader for $35 and tags for $2.00. The only problem the RFID has a reading distance of 8 inches. A UHF system is in the thousands of $$.
will help you remember their names. This is one of the weirdest ideas I've heard in a long time. While the triangulation itself stimulates my nerdvous system the other aspects make me think you're creating the next fascist superpower. Tracking everything you own so you can scold your spouse or kids for moving something? Say, do you work for the recording industry?
Couple this with the Shoogle cellphone concept could make for a really interesting and entertaining witch hunt. Imagine assigning different sounds to each RFID in the house.
You could listen for that certain item and follow your ears rather than overlooking what is under your nose. Put an RFID reader in every entryway and you'll know when the item leaves or enters a room.
The only cons: might be hard to fall asleep at night without a mute button. You may find all your stuff in one room when the kids decide to play a game of "lets see how many sounds we can have in one place".
So now we need to wrap tinfoil around our tires?
There is some relatively cheap technology available for avalanche rescue that would definitely have the range you need.
Although a traditional transceiver is a little bulky (a bit bigger than a mk1 iPod) and expensive (€200-€500) to be used used on multiple items, the modern systems CAN distinguish different units (I have a friend who is a professional mountain guide and with the modern Barryvox gear he could tell which buried body is his girlfriend and which is his client).
Alternatively the RECCO system may be more suitable:
http://www.recco.com/startsida/index.asp
The chips are pretty cheap and you'd only need one detector. The only problem is that, AFAIK, it cannot distinguish between different objects, i.e it will show you where ALL the RECCO chips are in the house but not which one is the hammer and which is the TV remote.
Maybe, with a bit of hacking, you may have more luck trying to develop something from this tech rather than RFID stuff?
I want a system like this, but for tracking cop cars in a small town...got to keep on top of those bastards!
Just as you pried open the links on your dad's chain, I'm sure that your
..
kids will figure out how to open your locked door. I know that a locked
door was only a challenge to me as a kid.
It's only a matter of time . .
A lot of funny comments, but I see a real need for small passive RFID tags. My father is getting on in years and he loses/misplaces small things. Like his glasses, which is a small problem. Like his hearing aids; family members are currently looking for a hearing aid that has been missing for over a week. And, like his false teeth, which he no longer has, because he/we cannot afford to continue replacing them after the first couple of times. I don't really need to identify the item uniquely, I just want a beep or proximity detection.
lock your tools in a secure closet, set an RFID lock on the closet door, have a subcutaneous RFID tag implanted in your arm or hand....
Finally someone else thinks that life needs a "Ctrl+f" function.
This is not so easy to do because of all the interference from walls, appliances, doors, people, etc. Indoor location detection is actually an active research topic.
I would look at systems compatible with home automation, like Crestron. A search turned up that Crestron specifically has partnered with Wavetrend for RFID tracking integration with their automation systems. Fairly expensive, but an option nonetheless.
There are open source alternatives for home automation, such as Pluto (www.plutohome.org). I know Pluto uses Bluetooth to track people via cellphones to turn on lights, etc. but I don't know if it will track RFID natively. It's open source though, so the option to add it is there if you have the time and ability.
I just read a paper that described using passive RFID tags to triangulate. The range was less than 1 metre and error was over 200%. Maybe with active tags you can get better results, but just think about the amount of batteries you will need to check and replace regularly!
Look into anti-collision techniques and determine if there are any that will be feasible on your budget. It's been months since I last looked into doing something like this, but then (around christmas) I couldn't determine a way of avoiding the problem of collisions cheaply.
Hope this helps..
I think it would be useful, even if I lived alone. Heck it would probably be more useful.
It has nothing to do with consideration, and everything to do with something simply being set down somewhere and you not remembering where - even if that place is where it's "supposed" to be.
I thought Woz was already working on some kind of home location tag system though that sounded more practical.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
accio
#include std_disclaimer.h
the problem with RFID triangulation is that you've got to have enough overlapping zones to actually be able to triangulate. Because RFID is on/off it's hard do do triangulation on it.
Bluetooth is a much better bet for locating things, but then you need a bluetooth device. Works good for people carrying phones or other portable communication devices, but not so much for "where are my keys".
PS No idea why there's so many useless comments posted these days. Signal/noise ratio on slashdot getting crazy. Come on people - I'd like to think the readers of slashdot are marginally intelligent, but you don't look that way.
I've been dreaming of a huge, yellow reader (so it is hard to lose) and a set of passive tags that have generic id's (not actual item identifiers).
Each user would put RFID tags on what they wanted and write the key on the back of the big, yellow reader. With high frequencies, range is no more than three meters, but that's enough to find something inside a home.
Cheers
Big Brother's the one loosing the tools. :-)
I've been toying with the RFID idea also. So a mysql database of all the tags and the items. Put items in a Contico with a tag, and hierarchically log whats in the box. The database is keyed on items, add a digial picture + description/audio clip. When you are about to search for that item that you know will be in the last spot, consult the database, find the Contico take the item out. Later, a quick scan of the item will reveal what box it needs to go back into. Something like that.
Hedley
Once upon a time, I too was single. When I put things down, they remained there until I picked them up again.
Then I got married, and the sudden Alzheimer's onset began. Things... Things began to move. It began small, tv remotes, car keys and the like. Soon it extended out to clothing, kitchen appliances. And then things began to just -- I'M NOT CRAZY DAMMIT! STOP LOOKING AT ME LIKE THAT! -- things began to DISAPPEAR. Treasured old jeans, t-shirts I'd had since high school, important tax receipts from 1992, they all began to just go away with no explanation.
Then the poltergeists came, and my wife insisted on calling them children. I fiercely hold my TV remote in my hand, knowing that if I loosen my grip on it it will fly across the room. Change on the desktop, shiny hand tools, anything that beeps, whistles or lights up, DVDs of any stripe, anything less than 60 lbs of dead weight can fly away in a heartbeat.
But I'm safe now, here in my closet. I got my favorite Leatherman, my surefire flashlight, my solid brass Zippo lighter and MY TV REMOTE DAMMIT and I am NOT LETTING GO OF THEM! NOT LETTING GO!
And I am not opening the door. They're MINE, YA HEAR ME? MINE!!!!!!
He put his boots up on the table and made a face. "The sig," he smirked. "You can waste your life in search of the sig."
Keep an eye on e-bay. Suggest you get some of the early RFID readers that are out there. Matrics/Symbol/Motorola AR400 is a start.
.02 seconds. The hardiest of tags will survive mild washing, freezing etc.
You'll need antennas, 900Mhz 6dBi gain are the most popular.
Using the AR reader you can put it into autonomous mode (it will read tags all by itself). A quick web based application cat hit the readers on occassion to see which antenna picked up a particular tag last.
Now, tag everything - old tax returns, TV remote etc. Perhaps car keys.
Be aware that RF has limitations. Dropping your keys in a fish tank will normally obscure the RFID - however, you should be able to tell which room it is in (where it was seen last).
Next, add tags to all the people (and dogs) in the house. Now, when the keys were last scene in the living room, you can correlate that with who was in the living room at that time - and even later.
The RFID readers are limited to 1Watt (30dBm) in the US by FCC, so you really want to pay attention to cables. I'm not sure what antennas go for, but you can make reasonable antannas yourself. On a reader like the AR400, you want to make a RHCP for transmit and a LHCP for receive (gives nice isolation) or vice versa.
Love to here how it turns out.
BTW, microwave ovens will kill tags in about
Some tags, if unprotected, will temporarily fail under intense incondensable lights. Turn off light and they will work again. Special tags will work well on metal (spaced off the metal by 1/8" or so). Yet other special tags will under water... Some of the biggest tags can be read at 40+ feet. The small ones, say 1"x1" are only good for a few inches. Size matters.
Class 0 has some performance advantages, but no one is making them anymore - maybe you can get some used ones cheap. The AR400 reader can read them as well.
BTW, if you have 900Mhz wireless phones (or other devices) in the house, forget it.
Look for "gen 2" (Specifically EPC Class 1 Generation 2) equipment.
WiFi tracking with 802.11 as discussed b4 on slashdot. Bluetooth is also possible, and likely to be cheaper than active RFID as well.
On the one hand you take life too seriously, and on the other, you do not take playful existence seriously enough. Seth
IT papa of a seven year old here, who has been touching "my" stuff for as long as he's been smart enough not to eat it. Builds pc's with me, mods, demoed the bathroom, installs his own software, does cabling, guitar tuning, even has his own pile of motherboards to creatively break. Point being, raising a kid to never touch your stuff may stick you with a kid who doesn't know how to do anything with your stuff, and suddenly here's you wondering why you have nothing in common with him/her ten years later. Don't just let the kid touch your stuff, encourage her to do it!
only one everything
Just tag the kids, so when something turns up missing you can start the interrogations immediately. Surely you have fewer kids than you have stuff?
"Time flies like an arrow. Fruit flies like a banana." - Marx
That is exactly what you are looking for.
and if you succeed in every mod to your house mentioned above...you can:
A: find your keys.
B: find your lost XXXX item
C: find your lost toddler (*slap..bad parent for losing toddler in first place)
d: find cowboy Neal.
as an about to be parent i say if you need RFID to find your stuff....try watching the kid...youll find your stuff if you watch the kid.
As the oldest person on slashdot (probably) the idea of having everying tagged so you can find it is a brilliant idea. I have to put numbers on drawers and make lists of where everything is. I have to put down my glasses and say loudly to myself "Glasses on top of the microwave". Why do I put them on top of the microwave? because that's the sort of thing you do when you are old, vague, confused, and read slashdot because you can't find anything useless to look at on TV even if you could find the control. Bear in mind that a very large proportion of old people live alone. Good luck to the person who suggested tags on everything -whatever his name was (of was it a her). Now...where did I put the cat, it was here a minute ago.
Hi there,
having implemented RFID goods tracking mostly at warehouse gates, I can tell you that it is not easy.
The approach of a few sensors and triangulation does not work well, because a professional (expensive) antenna, does hardly read across the room.
The approach to track on critical points, like doorways is complex, because you can't determine if something traveled in or out of the room. Unless you use its position as in the room, and determine it must have gone out. But what if the kid only went near the door or turned around in the doorway. At least you can say it has been last seen upstairs, so it is unlikely downstairs.
I'd opt for a simpler system to educate/train the children that these are items not to leave the room. Simply create a buzzer that sounds if someone passes the item through the door. That way you teach your children the right behavior, not to remove an item from the room/place.
By the way, even if you build such system, by the time you have it really working, your kids will be through the phase that they move your stuff around.
Just my two cents.
Busy helping non technical users of OpenOffice.org - http://plan-b-for-openoffice.org/
And what makes you think the RFID tags will remain attached to the objects in question? The only thing kids like more than putting stickers on things is pulling stickers off of things.
https://www.eff.org/https-everywhere
You should maybe look into rewriting this so it doesn't sound precisely like an urban legend chain letter.
$x='S24;r)>63/* h@<5+oZ)32"5cz';$me='phroggy'x$];
$x=~y+ -xz+\0-Tx+;print$_^chop$me for split'',$x;