Pet RFID reader - Page 1
Forum section: electronics / projects

author: Sparks
author_rank: Contributor
timestamp: August 24, 2015, 09:09:59 pm
content: I'm thinking of a little project to keep me busy this semester, and was wondering if any one out there had any information on making a reader for a pet RFID reader. A google search so far gave me some basic frequency data but not much else.

author: Sparks
author_rank: Contributor
timestamp: September 09, 2015, 07:08:02 pm
content: thank you, that was helpful.

author: German_EE
author_rank: Super Contributor
timestamp: September 09, 2015, 07:45:00 pm
content: Go speak to a friendly local vet, the at least you can find out what frequency they operate on. Your main problem will be holding little fluffy long enough to a) find the chip and b) read it.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: September 09, 2015, 07:51:34 pm
content: There are a few different standards for this - some proprietory, some documented. Frequencies are 125 and 134KhzThe tag antennas are small and you typically need a pretty highly tuned antenna - peak voltages of 300-400 volts are not uncommon.

author: amyk
author_rank: Super Contributor
timestamp: September 10, 2015, 01:23:57 am
content: Quote from: evb149 on August 28, 2015, 02:33:36 amGoogle works, it giveshttp://www.cypress.com/file/47781as the first result for searching "AN52164"

author: timofonic
author_rank: Frequent Contributor
timestamp: January 04, 2016, 04:36:13 pm
content: Quote from: chrichri101 on October 15, 2015, 09:46:44 pmAs a guy with many cats at home and former active activist in animal rights groups, I'm very interested on it.I have been procrastinating for looking projects in the forum and found yours.I wonder if it's possible to make a long range reader, it can be useful to find lost pets.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 04, 2016, 04:48:03 pm
content: Quote from: timofonic on January 04, 2016, 04:36:13 pmNot with existing passive tags, due to the inverse square law.A very rough rule of thumb for range of 125KHz RFID is to imagine the antenna coils of the reader and the tag as each being wound round a sphere. Range is of the order of the intersection of these two spheres, and falls off very rapidly outside this.The only way to do long range is a battery powered active tag.

author: nctnico
author_rank: Super Contributor
timestamp: January 04, 2016, 05:51:27 pm
content: Not quite so. A 125kHz tag feeds from the field and loads the field to send information so the distance you can achieve depends on the field strength and the sensitivity of the receiver. Don't expect to achieve ranges over 1 meter (which will be difficult!) with a small tag.

author: timofonic
author_rank: Frequent Contributor
timestamp: January 06, 2016, 08:15:21 pm
content: Quote from: nctnico on January 04, 2016, 05:51:27 pmDamn. I hoped currently commercial and obligatory tags that are under the skin would be more useful.A long range tag would be very invasive and dangerous for a cat or dog, right?

author: Fred27
author_rank: Unknown
timestamp: January 06, 2016, 08:27:00 pm
content: The read range on the embedded glass tags will be a centimetre or so at best. I've got an NFC tag (similar to pet tags but 13.57MHz) in my hand and you pretty much have to be in contact with the reader.

author: tautech
author_rank: Super Contributor
timestamp: January 06, 2016, 08:44:32 pm
content: Here in NZ we have a compulsory RFID tag system for farmed cattle and deer called NAIT.RFID ear tags and mostly handheld wands are used for implementation, but there are some stockyard walk through systems available that will be reading the tags from ~1m or less. What their reliability is I don't know.Anyway a few links for your study:http://nait.co.nz/nait-basics/https://am.gallagher.com/nz/products/weighing-and-eid/eid-tag-readers/G03303http://www.allflex.co.nz/readers_yellow_reader.htmhttp://livestock.tru-test.com/en-nz/help-nait#WhatEID reader is right for me?

author: nctnico
author_rank: Super Contributor
timestamp: January 06, 2016, 10:59:58 pm
content: Quote from: Fred27 on January 06, 2016, 08:27:00 pmLike I wrote earlier: the range depends entirely on how the system is constructed. In case of contactless payment systems the range of the receiver is probably very small on purpose to prevent the field being picked up. You can't say 'oh this RFID/NFC system has a short range so every RFID/NFC system has a short range'. It's the same with wireless charging which works on the same principle. Some systems are designed to be short range while others are designed for longer ranges.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 06, 2016, 11:10:19 pm
content: Quote from: nctnico on January 06, 2016, 10:59:58 pmThe range of passive tags is very much limited by the laws of physics, in particular the inverse square law.

author: xygor
author_rank: Regular Contributor
timestamp: January 06, 2016, 11:42:11 pm
content: Quote from: mikeselectricstuff on January 06, 2016, 11:10:19 pmWas this enacted by Parliament?We don't have such laws on the tags here. But the FCC does limit the power output of transmitters.Edit: Sorry, this seemed funnier in my head than it looks in type.

author: nctnico
author_rank: Super Contributor
timestamp: January 06, 2016, 11:45:08 pm
content: Quote from: mikeselectricstuff on January 06, 2016, 11:10:19 pmPart of my previous job was designing long range 125kHz RFID systems so I do have some hands on experience with them to say the least. Your two sphere model doesn't apply because the tags are not transmitting back! The beauty of the system is that the tags load the field which they are in just like you have a shorted turn on a transformer. The further the tag is away the more field strength you need to read it and the smaller the current variations will be in the received signal.

author: timofonic
author_rank: Frequent Contributor
timestamp: January 07, 2016, 12:00:45 am
content: The current systems are very small and under the skin. I do wonder if it can be possible to build a long range system to detect the animals in case they get lost, because "playing" (despite the surgery, some of them still like sex and that happened with some of my with female cats) or got injured because accident or fighting with cats (I always do the proper surgery to make them less sexually active, but there's the territory issue) or dogs.I often found many of my cats killed (sometimes car accidents, but we have high suspicions many "neighbors" put poisoned food in the streets and catched one of them) or never back again. It's a terrible situation I suffered too many times. You can't understand it if you don't have companion animals (pet is a term is dislike, but I'm too radical and vegan), this is a very common situation with cats.Some of my cats are smart bastards, but others are shy and unable to defend themselves or run away properly. Anyway, I worry about all them and would like to use the Power of Electronics(TM) to be their benevolent Big Brother.Any external device is mostly useless: Cats generally dislike anything attached to their body, so there's must be some kind of eternal and not dangerous surgery to implant the device.I would love to have a low cost long range rfid tags (I have tons of felines, long story) to detect the location of the cats and notify me or trustful people and notify if they are in dangerous zones.--- Radical and acid rant about psychopathic humans hurting animals ---The situation would by neutering the problematic individuals: Those filthy humans with psychopathic behavior but very cowards so they hurt animals (at least in public) shouldn't reproduce and raise children to avoid having an even more destructive humanity.(I accept about neutering cats and take care they have their space, instead invading nature and destroying it).

author: nctnico
author_rank: Super Contributor
timestamp: January 07, 2016, 12:56:24 am
content: Slightly off-topic: sometimes cats go out and find a new home especially if your place is too crowded with cats (that is how my parents got an extra cat; he just didn't want to go away). And cats do tend to get themselves killed while crossing a busy street. AFAIK the only way to have some kind of tracking system for a cat is to have a beacon around it's neck which sends out a signal which you can trace. Many cats wear a collar so it is not a no-go as long as it has a weak link so the cat can't hang itself from the collar.

author: Richard Crowley
author_rank: Super Contributor
timestamp: January 07, 2016, 02:18:04 am
content: Quote from: mikeselectricstuff on January 06, 2016, 11:10:19 pmWe have RFID chips (and multi-turn loop antenna) embedded into our standard-size plastic ID cards at my employer.We use them for both initial access into buildings and other secure areas, as well as for access to internal areas, and even for automatically pulling up our files at public printers. Or for buying computer accessories at special vending machines. But it is pretty much direct contact (or maybe a VERY FEW mm at the most).We used to have big door-size "portals" that would read your RFID badge as you walked through at a normal pace. (Cleverly, we called them "Star-Gates") But they relied on a pretty hefty RF field to operate at that distance and they were deemed not reliable enough in the long term, so they ditched them.My manager's husband puts on various foot-races and I thought it would be clever to make a device to automatically detect when runners crossed the finish line. But it turns out to be impractical to use ordinary RFID devices for a finish-line system that was reliable enough to make it worth the effort to assemble.

author: timofonic
author_rank: Frequent Contributor
timestamp: January 07, 2016, 04:04:07 am
content: Quote from: nctnico on January 07, 2016, 12:56:24 amYes, they don't like crowded places. I agree with them at that and would do the same! I just would do a visit occasionally and eventually after some time congratulate to their new human buddies. Some of my cats found new places to live and I know their locations, it's nice while they feel comfortable at their new placeI'm skeptical about beacons in their neck: Some cats end to be used to them, others are insanely stubborn and always end removing them (most of my cats are even more stubborn than me, figure it!). While cats are smaller, their body is very sensitive and flexible, so many of them prefer to have their body free of any shit.Would there be another alternative despite it can be surgical? The device needs to be small, inserted in a very easy surgical procedure, very long autonomy (not needing power or using some very low power signal plus one of those peacemaker batteries?) and able to detect location in some way.I know this is a crazy and difficult idea, but I find current RFID tags useless for finding them.

author: timb
author_rank: Super Contributor
timestamp: January 07, 2016, 08:22:41 am
content: Quote from: timofonic on January 07, 2016, 04:04:07 amRFID tags aren't designed to help you find your pet in that way. The idea is, if your pet gets lost, odds are someone will find them. They would then take them to the vet, shelter or pound, who scans them and calls you. Collars can come off (and in fact they should, as they can become snagged, so your pet *should* be able to pull out of them given enough force) which is where an RFID tag is the only way for the authorities to identify them and contact you.Another benefit of the tags is pet theft. It allows you to unequivocally prove the animal is yours.There is no way in the foreseeable future to inject an active homing bacon under a dog or cat's skin. Though, radio beacon packs have gotten really small in recent years; you can get them that about the size of a match book now. Battery life is much improved too. (Keep in mind these only use radio direction finders for location. Hunters that run dogs commonly use them.)There's also cellphone transmitter equipped packs with GPS now. They use geofencing to alert you if your pet goes outside of a defined area. Then they phone home with the current GPS position every 10 minutes or so. Battery life isn't great on them though.For that last option to really work, you really need something like WiTricity that could charge the unit wirelessly from a distance. Then make the unit completely sealed and ruggedized, maybe even build it all into a neoprene covered collar with flexible PCB materials; perhaps a flexible solar strip on the outside as well, for increased runtime and the ability to self-charge in case your pet *does* get lost (then, once the battery wears down, it goes into standby and only updates every 30 minutes or something).Aside from the wireless charging, the rest of that technology is very close to being small enough. In fact, if you had a few million to spend on development it may be there already.

author: AndreasF
author_rank: Frequent Contributor
timestamp: January 07, 2016, 04:47:41 pm
content: Quote from: Richard Crowley on January 07, 2016, 02:18:04 amAren't these types of systems extremely common these days? E.g.http://rfidtiming.com/I guess it depends on what you mean by "ordinary RFID".

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 07, 2016, 06:05:04 pm
content: Quote from: nctnico on January 06, 2016, 11:45:08 pmThat approximation was based on obsevationof actual systems, and was meant to illustrate that it depends on the combined size of the antennas. The fact that the tag only passively modulates the excitation field isn't that significant - with a huge field strength, the modulation will disappear into the noise so it has a similar effect.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 07, 2016, 06:17:36 pm
content: Quote from: Richard Crowley on January 07, 2016, 02:18:04 amThese would probably have been 13.56MHz - 125K has significantly less range

author: Richard Crowley
author_rank: Super Contributor
timestamp: January 07, 2016, 07:17:34 pm
content: Quote from: AndreasF on January 07, 2016, 04:47:41 pmBy "ordinary" I meant the fraction of a cent, garden-variety RFID tags that operate at 125KHz or 13.56MHz.Those racing systems appear to be using UHF or even microwave frequencies.