Coin: The product that had to be perfect. http://willd.me/posts/coin-the-product-that-had-to-be-perfec...
http://forum.xda-developers.com/general/off-topic/coin-vs-pl...
A quick search confirms the caveat:
https://support.onlycoin.com/hc/en-us/articles/204413864-Whe...
(first link noted from a previous discussion here: https://news.ycombinator.com/item?id=9879699 )
This is a (probably less severe) variation of the problem that iCache [1] had. The dynamic magnetic stripe tech was immature then, but mostly, it's just really difficult to put a computer in a thin (read: flexible) object that people are used to abusing. Then consider the need for near-perfect reliability next to the promoted benefit of not carrying other cards, and you're screwed.
1. https://www.kickstarter.com/projects/1404403369/geode-from-i...
The specs aren’t listed on the FDK site but the safety
data sheet shows it is a 3V battery although amperage is
unclear.
All lithium-ion batteries have a nominal voltage of 3.7V, like how all alkaline batteries have a nominal voltage of 1.5V. It's just how the chemistry works.(Actual voltage can vary quite a bit, depending on where you are in the discharge curve: http://i.stack.imgur.com/UkodS.gif)
And to be somewhat needlessly pedantic: you want "amp-hours" there, not "amperage". Amp-hours is the unit of capacity, amps is how much current is being drawn at that very moment. In the automotive metaphor, amp-hours (or watt-hours) is how big the gas tank is, while amperage is engine horsepower.
Single-use lithium batteries are made in a variety of voltages. This chemistry is in fact three volts.
It's a really cool idea. I actually wonder what the technological hurdle was that held them back - mechanical (reliably magnetizing the coils, easy-to-break components due to narrow size), software (programming issues), or QA (reliable SoCs, reliable builds, reliable solders)?
There are at least 4 cards that I need working at all times: (1) Debit card, as you mentioned, to be able to withdraw cash in a pinch, (2) Chase Sapphire Preferred - card with no FX fee, (3) Corporate Amex for charges I don't want to take on personally, (4) Starwood (SPG) card to amass a non-negligible amount of points on hotel stays. And maybe a 5th on which I'm trying to spend a large amount on quickly (for example - I might be planning to put $1500 on a random card with a big signup bonus, and it might be critical for me to get points I need for an upcoming reservation)
I of course have all of these loaded into my Coin, but each has failed enough times (forcing me to use the debit) that I started carrying the others as backup. Then I found myself carrying 5 cards....plus the Coin. And if Coin is targeted to users like me (who carry multiple credit cards, optimizing for different uses)....then what's the point?
I think that the coils that drive the magstripe are only activated when the buttons to the left or right of the stripes are depressed (e.g. by the process of swiping).
Also, I believe coin only transmits track 2 [2]. Why it looks like there's 2 coils is curious to me as well.
[1] https://fccid.io/document.php?id=2397353
[2] https://support.onlycoin.com/hc/en-us/articles/204263414-Coi...
Some merchants require your full name (also known as Track 1 card data) as a part of the transaction process. Coin does not transmit Track 1 data and may be rejected at the point of payment.
Conductive rubber pads and/or membrane switches are always a bad thing. Necessary for this design, but they'll always fail you in the end.
I can't describe in words how much I felt like a total, utter failure. All the fears I had about how I was going to pay my bills that month, the pressure from family to pay them back for money borrowed, the pressure from roommates to come up with rent - all came bubbling up in those moments.
After all, I was the first kid in my family to go to college. I was the smart one who was supposed to have his shit together, but there I was - totally broke. It creates a fear that is not rational and hasn't gone away (at least for me).
About a year ago, I forgot my bank card at TJ's and only had $20 bucks on me. I was embarrassed in ways I can't describe. I was cold sweating to the point I was soaking my shirt. I had to leave everything except for some essentials I needed for that night. One of the cashiers lent me $5 to help me pay for my groceries (I paid him back). I feel weird that I accepted the $5, but I wasn't thinking rationally. I wanted to scream "no, really, I have my shit together now." I kept telling myself that this is not a big deal... chill out... But I just couldn't calm myself down. It was like poverty PTSD.
Even though I now have paid off all my debt, school loans and have a healthy nest egg, I still have these fears. Whenever my card won't go through on the first try or I type in the wrong pin number, my heart jumps.
It's entirely irrational.
On the flip side, that retailer has just seen 100 people in a row use their plastic just fine, then you come along with your whiz-bang phone or Coin card or whatever, and start failing. The embarrassment comes from everyone else waiting behind you thinking to themselves, "Why not just use a card like everyone else instead of your complicated technology?" Or, "HEY EVERYBODY! LOOK AT THIS GUY WHO THINKS HE'S TOO GOOD FOR REGULAR CARDS!"
To be clear I don't pooh-pooh these things. I totally understand why people would like to ditch a stack of cards for a phone or Coin replacement. Just explaining why it might be embarrassing to rely on these replacements, and then have them fail.
Another common cause of credit-card-swipes not working is card declines. It's fairly obvious to the user and cashier, but potentially embarrassing if the people in line behind you assume you've maxed out your credit card/drained your debit card.
At least in the US, there's sort of a social phenomenon of de-emphasizing the payment process at restaurants. Checks are left on the table with a 'whenever you're ready' attitude, and often are not brought until requested. Cards are left on the check and taken away, often silently, to be processed. Checks are kept out-of-sight, for each payer to process individually without a lot of discussion, and tips are usually kept private. All of this amounts to awkwardness if something brings attention to the whole process.
Additionally, since cards are picked up and processed elsewhere, it's awkward for the payer if the waitstaff has to come back and explain that your card didn't work and wait for you to bring out another. Doubly so if they seem busy already, or if you already feel guilty for inconveniencing them by, say, splitting a check in a complex way - which is common for a large class of people, including me. Though I've noticed there's a different large class of people who find this guilt ridiculous.
On top of all this, there's a very real stigma around cards being declined for having insufficient funds. This doesn't really happen in the world of fairly well-off techies, but, running out of money (/ maxing out a credit card) is a very real problem for many people.
Not to mention the awkwardness of 'being the person using newfangled tech'.. and then having it not work on you.
Imagine you've asked someone out on a date and you offer to pick up or even split the check but your card gets declined. I think most people would find this at least moderately embarrassing especially if they don't have a backup payment ready.
I believe the "embarrassment" trope crops from the misunderstanding behind the motive.
Personally, I will often leave any alternatives to the one payment method I intend to use locked in my car.
Oh exactly. Who cares what someone else thinks? You are only causing a brief delay for the people behind you.
But ultimately the way they've chosen to do this seems to be very difficult, especially if those are two very long single coils. It feels like it would be much easier from the software side if they had made them addressable somehow so that they could control every bit individually by either energizing or not energizing a particular coil. Then you'd have eliminated the swipe speed variable from the equation and a lot of complexity would drop right out.
Honestly looking at this teardown I'm surprised it works at all.
There are patents for dynamic magnetic stripes that have individual coils for each bit. That is probably way too costly for this design, or perhaps too expensive to license it.
I'm interested in knowing which component failed? did the second card fail in the same way? or was that remedied in the revision?
Did the display and button still work?
Hopefully the issue was with the coil, flex PCBs and displays are more or less a solved problem, batteries not so much.
With the Nordic 51822 they're lined up well to roll out NFC after the mandated phase out of mag-strip in the US (p.s how are they still a thing?).
It'll be interesting to see if they'll survive if a chip-and-pin foothold overshadows NFC.
I decided to try out Plastc after that. We'll see what that's like.
-Chip-and-pin? The card reader probably can't read it.
-Apple/Google wallet and similar services? The card reader probably doesn't have an antenna for it. (Especially small retailers who can't afford the special card reader)
-NFC Visa/Mastercard? The card reader probably doesn't have an antenna for it.
-Paypal? Most retailers aren't set up for it. That's why Paypal issues magnetic cards in the USA.
-Paper checks? Most retailers don't want to lose money on the possibility of fraud. And most card readers can't auto-ACH a check.
However, the transition is coming to the US sooner rather than later. Banks want to see this transition happen quickly so that they can reduce fraud rates. Merchants that don't want to spend money on new terminals will be prodded along by the banks pushing fraud liability over to them.
This all ultimately means that this iteration of the Coin Card (mag-stripe only) has a pretty limited shelf life.
Then again, the whole credit card system which is popular in the US is even more hilariously insecure (you only need a picture of the card!!) and it doesn't seem to have stopped anyone.
I can't remember what it was called, but I remember reading about something that does use a chip card and allows you to switch payment providers using a phone app, but they were actually acting as a payment processor and had agreements with the card providers that they support to redirect charges to whoever you had selected at the time.
Too bad the product is unreliable or else I would get one right away.
Uhhhh...no? I've lived in the US my entire life, and while I've seen pin and chip readers, I've never had a pin and chip card, never known anyone who has ever had one, and never seen one used. Ever.
Note that it is Chip and Signature though, not chip and pin.
The Coin card was never going to sell outside the USA (not that that's a small market or anything! But even the US is going to move on eventually).
Perhaps their tester just couldn't probe the smaller pads/components. In general, any shipping product these days is going to have a significant number of test points, it is just that they are often not explicit.
Actually the nRF51822 is starting to pop up in a lot of products, especially those that use BLE. The BBC Micro Bit will be built around it: https://en.wikipedia.org/wiki/Micro_Bit
Card would still be useful for terminals that don't support NFC payment. Or for larger payments than are allowed with NFC. Or for people who prefer to use cards instead of phone/watch.
It should be possible to use the tokenization system of Apply Pay to have switchable card with chip-only card.
The toolchain for building firmware is crazy. It's kind of like in webdev we dynamically generate css through sass and then put it through all these different stages (minification/etc). Except this is all old school Makefiles. Made me cringe a bit.
dynamics seemed to have all the pieces in place to do the same thing.