Coin Card Teardown
bitsofcents.com
bitsofcents.com
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 )
Coin: The product that had to be perfect. http://willd.me/posts/coin-the-product-that-had-to-be-perfec...
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.
(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)?
You might get better results with bare die+wirebonding, then encapsulating with slightly flexible epoxy. That would allow the bondwires to flex and take up the bending. Doesn't help with the discrete components or the battery.
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.
Personally, I will often leave any alternatives to the one payment method I intend to use locked in my car.
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.
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.
[1] http://mentalfloss.com/article/50199/how-does-plastic-bag-fi...
[2] http://www.popsci.com/article/2007-11/cure-failed-credit-car...
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.
I believe the "embarrassment" trope crops from the misunderstanding behind the motive.
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.
I know plenty of friends who can't (for one reason or another) imagine what life would be like where their credit card is declined due to a "human error." Maybe they haven't had to live paycheck to paycheck or maybe their brains aren't wired that way. I'm inclined to lean to the former but I'm sure for some it is the latter.
(That said, it sounds like the person you're replying to is in the US.)
I actually create that feeling now by moving all but the bill paying funds to savings. Every 2 weeks it feels like I am broke. It gives me a sense of ownership and a feeling I am in control of the situation.
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.
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.
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.
This is clearly vaporware, or worse yet, a scam. Have they demonstrated a working prototype yet? Everything on that page is renders. If they haven't, there's no way they're shipping it next month. And features like e-ink screen and Chip&Pin cloning make it even less realistic.
That's really ignorant. Bank card security sucks enough without mag stripes (I'm looking at you, online payment). Really, magstripes need to die.
Not at all, sounds like you to need a little review yourself [1]. At no point in my comment did I support mag stripe, just simply explain why it's still in widespread use. If you ever have worked in the finance industry you would understand that. Nobody is arguing that it should stay, but it's important to understand WHY they are still around. Just because it's the major standard doesn't make a good one.
Ignorant? Really? I expect more constructive comments here on HN instead of running around and calling people's comments "ignorant". Perhaps you need to review the HN Guidelines [2]. Specifically: 'When disagreeing, please reply to the argument instead of calling names. E.g. "That is idiotic; 1 + 1 is 2, not 3" can be shortened to "1 + 1 is 2, not 3."'
Alas, it will not be happening based on the latest abuse of downvotes on HN.
[1] https://en.wikipedia.org/wiki/List_of_countries_by_GDP_%28no...
"The rest of the world is irrelevant" doesn't go over well and gets downvoted because it's obviously false.
On credit/debit card transaction volume North America represents 40+% of global market.
https://www.capgemini.com/resource-file-access/resource/pdf/...
The USA does have a huge economy. However in this matter it does not dictate the standard, and there are more people doing more card transactions outside the US, with non-stripe technologies, than there are in the US doing them with.
The USA is an anachronism here, the rest of the world has moved on and has other standards.
-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.
The cards they issue are pressed at the main branch; I had to wait while they printed my latest card. The process they use to print doesn't emboss the card - the little numbers don't stick up - and as such they have nearly rubbed off from the card.
I got that most recent card in September of 2012, and it's already wearing out; the magnetic stripe hasn't been reliable for 6 months, and the numbers are so worn off the front that cashiers have trouble hand-entering it. It doesn't even have the Mastercard NFC antenna.
I really, really doubt that most of the USA's banks are anywhere near ready for a transition.
Regardless, the changeover has already started. It may take a few years to be complete, but the writing is on the wall.
Be prepared for a lot of merchants not willing to take that risk and to decline your card if it has a mag stripe only.
The silly thing is that the US is mostly standardizing on chip and signature, which means that if your card is stolen, it's still easy for criminals to use it until you're able to block it.
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.
It may be useful for loyalty cards, but even that has similar problems with the cashier being confused/skeptical, or just the hassle of talking about it when you just want to finish your transaction and leave. Apple Pay has apparently opened the way for loyalty cards over NFC[1], so hopefully that will keep spreading both in merchant numbers and availability on other mobile platforms.
[1] http://9to5mac.com/2015/06/10/verifone-apple-pay-loyalty-car...
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).
It's not so much the USA as it is the American financial sector. Finance moves at a glacial pace.
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
Anyway, that doesn't change that you can't clone the chip's contents. Perhaps you could punch the chip out (like a sim) and array a few of them inside a next-gen type of Coin card.
Chip & signature answers the "Amazon laughs at your chip&pin card" loophole I had been sort of half puzzling over.
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.