Be Excellent To Each Other

Hello *curtsies*

Please, company of assorted nerds, gees and science-bods, help me out.

What kind of magic is it that makes Oyster cards work? How do Oyster card readers 'read' Oyster cards? I remember that somebody here once deconstructed an Oyster card with acetone, or something similar.

Somebody I know was thinking of making herself a little pouch to hold her ipod touch and oyster card, a few teabags and a map together, but wondered if the Oyster card readers used magnetism or anything else that might damage the iPod? Anyone know?

No, they don't. The work the same way that pet passports do.

http://en.wikipedia.org/wiki/Radio-freq ... tification

However, smacking said pouch on the card reader might not do the iPod any favours.

It's not technically RFID either Grim..., it's a proximity card / contactless smart card, which works at 13.56MHZ, powered by an RF (mostly magnetic) field from the reader.

What you might find is that the metal of the ipod shorts the field from the reader so that you can't use the card unless you take it out of the wallet.

I know, I worked for the company that invented them.

Funnily enough, I didn't think that was relevant.

[edit]Post-edit


Er... Or not.

She could do what Lave did and dissolve it in some form of SCIENCE liquid and then use all the strands of wire as a sort of attractive thread to embroider the pouch with. That would be awesome.

You worked for Philips?

I was going to suggest that, but then remembered that you have to be able to produce your Oyster card for it to be valid, so didn't think I should.

I also couldn't remember who did it.

Yes, that would be awesome: do that. edit: Or not.

It was Acetone.

Nah, the company that first thought of jamming the gubbins from a Pet Passport (which they might have invented as well, I'm fuzzy on that) into a "smart card".
They failed to capitalise on the concept superbly.

OK, so the main problem would be that the iPod might interfere with the card reader, rather than the other way around, and the magnetic field shouldn't be strong enough to adversely affect the iPod Grim.../Kalmar?

Yes, there's nothing in the ipod that can be affected by the very mild field from the reader (or even by a strong field tbh)

In terms of blocking the signal I'm thinking of the ipod touch here - if you mean a nano then it might be OK, as it's smaller than the card antenna.

I just tried reading an oyster card up next to my iphone - it didn't work.

What? It should be fine. Bloody cheap Oyster cards.

Also: Are you in London? Or does Scotchland have Oyster things now?

Nothing to do with the card - I didn't expect it to work, the phone is mostly metal. Especially with the card on the other side of the phone it doesn't have a chance.



No, I just happen to have oyster cards and a card reader on my desk

It's an iPod touch. She said she's going to try it as the iPod/teabags, etc will all be separated, and if it doesn't work it's no big deal. She was mostly worried about it breaking the iPod with secret magnet magic happenings.

Yeah, me too.

( )

I'm envisaging a case that is about the size of a fat hamster. Put the card on the other side of the teabags from the ipod, and present that side to the reader, it will probably work. Let us know!

Maybe the padding and stuffs of the and anti-magic fabric will help make it work.

Yeah, it's really the reader. We cobbled together a reader that could read a slightly-thicker-than-a-credit-card card inside a car from a distance of a couple of meters. The power involved made us decide not to market it, though.

FTFY

The tags that the rest of the world uses for congestion / toll charging use IR, I think. But that means a battery in the tag..

*ponder*
Adding NFC to the iPhone 5 must be a bit of a challenge!

I'm now wondering whether an oyster card would work from within a fat hamster. Let us know!

http://www.nearfieldcommunicationsworld ... he-iphone/

Stupid NDA means I can't tell you all about that, although it's nothing that you can't find on the Internet.
The way they do it for other phones is cleverer, IMO.

Meh. That's called sticking a contactless card on the back, and it won't work, as I've just demonstrated

It needs to be an active device built into it (Like Nokia did), and even that will require some hardcore black magic given the form factor of the phone. Apple must be working on that, this is a stopgap at best.

It will, think about it.
Stupid NDA.

http://www.nearfieldcommunicationsworld ... -solution/

It's not a stopgap, the articles show live hardware being trialled.

Ah, ok it's an active device built into a case, powered from the iphone by plugging into it (yeech).

So it'll work. It's still a massive kludge, why not just wave a contactless card or keyfob instead? Vastly cheaper.

More things to take with you, innit?

Also, NFC does device-to-device. Can't do that with two passive devices like cards.

Not a fat hamster, but experimenting of some kind has taken place. using a past iPod case that was knitted, test subject 'M' put the Oyster card in the 'earphones pocket' of the case she had made here

Twitter report in full:

Good work!

That reminds me, I have a knitted iPhone case a bit like that..

I did send Agent M a link to this conversation. She enjoyed that nobody questioned the sense of an iPhone/teabag/Oyster cosy and that things are measured in hamsters.

Spooky, I originally typed 'good work, agents'.

That ungainly hack is only because of iPhone limitations. For other phones, they are making a micro SD card that combines normal memory with the NFC bit. That's extremely neat, it means it's built into the phone from the here's perspective and solves the chicken-and-egg problem to get the devices supported.

yeah, was I who dissolved the oyster card. New oyster cards seem to have been constructed in a different way and so can't be dissolved with out break g the induction loop now. So that boat has kinda passed.