10 ms·

Coin Card Teardown

171 points by monkeypod 11y ago

mmosta 11y ago
Pretty cool. 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.
joshstrange 11y ago
I had the beta and a final Coin and neither one were reliable enough to to trust. You HAVE to carry backup cards which more or less defeats the purpose. Then there is the slightly embarrassing, extremely annoying "Your card didn't work/Do you have another card this one isn't swiping". I've stopped carrying my coin altogether because if you have the cards you might as well use the real ones (I tried for 7+ months to use coin first).
- jdhawk 11y ago
  Ditto - great idea - just never works reliably
  - pbreit 11y ago
    Possibly letting me leave 1 or 2 cards at home is not really a great idea.
- markbnj 11y ago
  They probably didn't have the ability to test it on nearly enough readers, given that there are literally thousands. They may also be running into some timing issues based on how people swipe. Those are things you sometimes just can't work out barring wide scale testing and adoption.
  - Someone1234 11y ago
    Right. But file this away in the "not my problem" draw. You can make all the excuses you want, but this is ultimately up to them to resolve, not for the consumer to deal with.
  - maxerickson 11y ago
    A comment here indicates that it simply won't work at a bunch of retailers: http://forum.xda-developers.com/general/off-topic/coin-vs-plastc-vs-stratos-vs-swyp-t3056219 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-Where-is-Coin-incompatible- 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 https://news.ycombinator.com/item?id=9879699 )
- wdages 11y ago
  This was my experience too. It simply has to work 100% of the time, and unfortunately doesn't. Actually wrote this up just yesterday: Coin: The product that had to be perfect. http://willd.me/posts/coin-the-product-that-had-to-be-perfect http://willd.me/posts/coin-the-product-that-had-to-be-perfec...
- goeric 11y ago
  Agreed. The coin absolutely failed me. It didn't work far too often for me and I always had to carry backup cards (my debit card because BofA's ATM can't read it, and my credit card because I still want my rewards on purchases when my Coin fails). Needing to carry 3 cards completely defeated the purpose of the Coin, and I ended up ditching the Coin just to have one less card in my wallet. The irony.
- jkestner 11y ago
  The concept is inherently flawed. Never mind changes in the payment infrastructure—the cool factor has apparently outweighed engineering challenges. 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-icache https://www.kickstarter.com/projects/1404403369/geode-from-i...
- tracker1 11y ago
  I've actually been meaning to try google wallet (pretty much everywhere visa/mc tap to pay and apple pay are available too) for some time, and just never think to do it... when I saw the coin card, I thought it was an interesting idea, but to be honest, I think having something along with your phone is probably more useful, since anyone with a coin card is likely to also have their phone.
- martingordon 11y ago
  Even worse, I've had servers flat out refuse to accept it. I couldn't even imagine opening a tab at a bar with it either: It looks too fake to be taken as collateral, and I don't know if the magnetic strip still works if the card is locked, meaning I would have to have another round-trip interaction with the bartender.
stephengillie 11y ago
What Coin has managed to do in such a thin package is really impressive. It’s a shame they weren’t able to do it more reliably. 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)?
- jaboutboul 11y ago
  It would have been nice if they shared any of that info. Maybe more of us would be more sympathetic.
- pjc50 11y ago
  I suspect flexing the PCB caused the usual problems of hairline cracks in solder joints, resulting in intermittent faults.
  - thaumaturgy 11y ago
    If that's true, I wonder if something like a paper circuit would work? e.g., http://www.instructables.com/id/Paperduino-20-with-Circuit-Scribe/ http://www.instructables.com/id/Paperduino-20-with-Circuit-S...
    - pjc50 11y ago
      Flexible substrates are not a problem - the industrial solution is polyimide (Kapton) or just really thin FR4. The problem is inflexible components. As soon as you bend a curved surface attached to a small flat rectangle (IC), it pulls at the joins. 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.
- ngoel36 11y ago
  Very often, the merchant would just assume I was using an Amex e.g. Amex Black....even though the display read VISA. This, of course, caused a decline...not worth the trouble to argue.
treycopeland 11y ago
I received my Coin about 2 months ago. I was excited to test it out after preordering almost 2 years in advance. The concept of having all my cards on one central card was a great idea. But having it not work at some locations was rather embarrassing and frustrating. I have decided the Coin was a fail and I will not carry it anymore. But, Coin, keep innovating. You tried.
- lvs 11y ago
  It sounds like just another startup hardware offering with a spotty launch. But I've always been confused about the perceived "embarrassment" of a card not working at the point of a transaction. This seems to be a common marketing trope in payments, but I don't know what it comes from. It's a piece of technology, and tech often doesn't work quite right. Sometimes my phone restarts itself. What's the big deal?
  - j_s 11y ago
    Assuming the point was to aggregate the cards, if the one payment option you brought doesn't work... Personally, I will often leave any alternatives to the one payment method I intend to use locked in my car.
  - GauntletWizard 11y ago
    It wastes your time, it wastes the cashier's time. It wastes the time of the people in line behind you. Isn't wasting people's time embarrassing? 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.
  - mildweed 11y ago
    The line behind me wondering why I'm not done yet. Also, by using a Coin, I'm positioning myself as somebody who uses great, new technology. When that fails, it reflects poorly on me. Now I'm the guy who spends money on something that doesn't work, but keeps brandishing it, perhaps for some ego reason.
  - 11y ago
myth_buster 11y ago
I'm curious to know whether given proliferation of the NFC alternatives available now like Apple/Google Pay is there a problem that Coin Card addresses which the former don't. Is paying in the restaurants one of those use case or will we see table side point-of-payments in near future which would make it obsolete.
- fluidcruft 11y ago
  For what it's worth, all of my banks have already replaced my credit cards with chip-and-pin capable ones in preparation for October's rebalancing of fraud liability between merchants and banks. I can't imagine merchants will be too keen to accept these Coin cards.
  - gambiting 11y ago
    Pretty much nobody accepts signature-only cards in UK, it's all chip and pin now. I am sure US will follow suit soon.
  - dboreham 11y ago
    Are you sure? I ask because the majority of US card issuers have opted to use chip&signature, not chip&pin cards. In my wallet I only have one chip&pin card (Well Fargo). The rest are chip&signature. Whether or not they send you a PIN is a good indicator of which auth method the card supports.
    - fluidcruft 11y ago
      Hmm. Perhaps not... I hadn't heard of chip & signature until your comment. I set the pin online during card activation, and hadn't thought about it closely. So, it obviously must be chip & signature. 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.
    - jonknee 11y ago
tdicola 11y ago
> It doesn’t look like there are many other products using the 51822 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 https://en.wikipedia.org/wiki/Micro_Bit
- mik3y 11y ago
  How's the toolchain support / dev environment for the Nordic parts these days? I remember the "other" popular chips (TI CC2540 and friends) had a gross and expensive requirement on "IAR Workbench".
  - tdicola 11y ago
    Luckily GCC works great with it as it's an ARM Cortex M0. I use the GCC ARM embedded toolchain here and haven't had issues: https://launchpad.net/gcc-arm-embedded https://launchpad.net/gcc-arm-embedded The only gotcha is that you need to sign up with an account on Nordic's site to get access to their SDK and libraries, however I'm pretty sure that's just a formality and it's free to sign up (just can't distribute its firmware source, etc).
Globz 11y ago
This is the first time I am reading about this product but why mag stripe over smart cards? isn't it less secure and deprecated technology? it seems very useful but relying on mag stripe isn't the best move, no? Perhaps they couldn't "switch cards" while using smart cards so mag stripe was the only solution?
- stephengillie 11y ago
  In the USA, magnetic swipe readers are EVERYwhere. And the collection of credit and debit networks connect every reader with almost every bank. It "just works" everywhere, and it's "impossible" for a retailer to be unable to connect to your bank. -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.
  - mbreese 11y ago
    Mag stripe readers are everywhere, but the banks have already started migrating over to chip and pin cards (with mag-stripe for backwards compatibility) for new issues. There are still older cards out there that won't expire for probably ~5 years or so, so I expect to see mag stripe readers around for at least that long. But it's fair to call it deprecated, even in the US. 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.
    - joezydeco 11y ago
      Target has very quietly replaced all of their terminals with chip/pin readers. It looks like they started shortly after their huge data breach, which makes sense.
dougb 11y ago
Coin is an interesting idea, but I figured https://www.dynamicsinc.com/ https://www.dynamicsinc.com/ would sue the pants off of them for patent infringement once they went to market. Dynamics CEO is a former patent attorney. dynamics seemed to have all the pieces in place to do the same thing.
nadams 11y ago
Was I the only one who canceled their pre-order after they asked for your social security number?
- jackreichert 11y ago
  I cancelled my preorder after I got the app and saw that silly tapping security code. I decided to try out Plastc after that. We'll see what that's like.
  - mildweed 11y ago
    After being burnt by Coin at $50, I'm not jumping at the chance to waste $150 with Plastc.
    - jackreichert 11y ago
      I hear you, I got my $50 refund, got some credit for finding a share link for Plastc and felt $100 was worth it for my single attempt at using the tech.
- cgriswald 11y ago
  Nope. And I was offered the chance to get the beta or wait for the real thing. I opted for the beta and never received either. The app when pressed would tell me "just wait it's coming"
yrral 11y ago
Fcc photos of the coin pcb here [1] 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 https://fccid.io/document.php?id=2397353 [2] https://support.onlycoin.com/hc/en-us/articles/204263414-Coin-Compatibility 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.
- mildweed 11y ago
  I certainly have been rejected because of the lack of Track 1 data. One merchant told me as much.
- joezydeco 11y ago
  It seems like a logical thing to do, especially when you're trying to a) save power and b) time the speed of the coil's "stripes" to make the reader think it's seeing a physical card. It's probably also the source of a lot of rejected swipes. 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.
ngoel36 11y ago
I was so damn excited to use my Coin - the idea was brilliant. I tried to so hard to use it, but with a 30%+ failure rate, it became completely useless. Simply not worth the embarrassing "Sir, your card didn't work" or "Is this real?". And if I have to carry backups anyways, what's the point?
- BrentOzar 11y ago
  I like it because it got me down from several cards (debit, credit card A, credit card B, business card, business debit card) to two (debit card, Coin). The debit card is my backup to Coin.
  - ngoel36 11y ago
    I formerly did the same, but it became insufficient. 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?
upofadown 11y ago
>I was surprised by the number of test pads exposed on the Coin - all those small metallic squares are programing points / test points. This suggests to me that Coin is still going though some debugging since it’s rare to see so many pads still exposed on a shipping product. 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.
ceequof 11y ago
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 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.
- Dylan16807 11y ago
  Lithium is not lithium ion. Single-use lithium batteries are made in a variety of voltages. This chemistry is in fact three volts.
  - ceequof 11y ago
    Whoops, guess I'm wrong.
deegles 11y ago
Does cloning your card to a Coin make you liable for fraudulent transactions? I assume it would be against the ToS for most cards to allow cloning.
- concerned_user 11y ago
  That is what signature is for, isn't it? If bank can't prove it is your signature then it is a fraudulent transaction. Technically cashier/clerk should not accept the transaction if signature doesn't match but I've rarely seen them check it.
scoot 11y ago
If the mag-stripe emulation is just a simple electromagnet, I'm curious how they detected the position of the read-head in order to modulate the magnet correctly to emulate the data that would otherwise be read at that point of a traditional mag-stripe. Or is it more sophisticated still?
- msandford 11y ago
  My guess is that this is why they have so many problems. I'd guess that there's probably an accelerometer somewhere to give them an idea of what the swipe velocity is, so they can know how fast to play everything back. 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.
  - joezydeco 11y ago
    Doesn't seem to be any accelerometers anywhere. There are two hidden membrane switches to either side of the coils. The card is probably using the press and release timing of that button as it travels through the reader to guess at the speed of the physical card. 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.
jackmaney 11y ago
I'm amazed that this idea actually caught on in the first place. "Wait, you mean I can put every single source of (non-cash) money in a single card, for a single point of failure? And if it breaks, I'm effectively penniless? WHERE THE FUCK DO I SIGN UP?!"
- concerned_user 11y ago
  Also imagine it gets stolen, good luck remembering all the cards you had in there and banks you need to call. Payment gateway route, like paypal, gives same convenience and less headaches.
dimino 11y ago
My Google Wallet card does the same thing this does.
jtchang 11y ago
I actually have the Nordic NRF51822 / NRF51 development board and it is super fun to play with. I come from a web dev background so getting into hardware is rough. 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.
sciencesama 11y ago
can we make eddystone beacon from this chip http://www.aliexpress.com/store/product/Bluetooth-4-0-BLE-Bluetooth-Low-Energy-CC2540-chip-Module-Iphone-4S/417006_819192101.html http://www.aliexpress.com/store/product/Bluetooth-4-0-BLE-Bl...
- leybzon 11y ago
  feels like it should be possible Eddystone is just a message format Some embedded coding skills will be needed thou

171 points by monkeypod 11y ago

Pretty cool. 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.

joshstrange 11y ago

I had the beta and a final Coin and neither one were reliable enough to to trust. You HAVE to carry backup cards which more or less defeats the purpose. Then there is the slightly embarrassing, extremely annoying "Your card didn't work/Do you have another card this one isn't swiping". I've stopped carrying my coin altogether because if you have the cards you might as well use the real ones (I tried for 7+ months to use coin first).

jdhawk 11y ago
Ditto - great idea - just never works reliably
- pbreit 11y ago
  Possibly letting me leave 1 or 2 cards at home is not really a great idea.
markbnj 11y ago
They probably didn't have the ability to test it on nearly enough readers, given that there are literally thousands. They may also be running into some timing issues based on how people swipe. Those are things you sometimes just can't work out barring wide scale testing and adoption.
- Someone1234 11y ago
  Right. But file this away in the "not my problem" draw. You can make all the excuses you want, but this is ultimately up to them to resolve, not for the consumer to deal with.
- maxerickson 11y ago
  A comment here indicates that it simply won't work at a bunch of retailers: http://forum.xda-developers.com/general/off-topic/coin-vs-plastc-vs-stratos-vs-swyp-t3056219 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-Where-is-Coin-incompatible- 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 https://news.ycombinator.com/item?id=9879699 )
wdages 11y ago
This was my experience too. It simply has to work 100% of the time, and unfortunately doesn't. Actually wrote this up just yesterday: Coin: The product that had to be perfect. http://willd.me/posts/coin-the-product-that-had-to-be-perfect http://willd.me/posts/coin-the-product-that-had-to-be-perfec...
goeric 11y ago
Agreed. The coin absolutely failed me. It didn't work far too often for me and I always had to carry backup cards (my debit card because BofA's ATM can't read it, and my credit card because I still want my rewards on purchases when my Coin fails). Needing to carry 3 cards completely defeated the purpose of the Coin, and I ended up ditching the Coin just to have one less card in my wallet. The irony.
jkestner 11y ago
The concept is inherently flawed. Never mind changes in the payment infrastructure—the cool factor has apparently outweighed engineering challenges. 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-icache https://www.kickstarter.com/projects/1404403369/geode-from-i...
tracker1 11y ago
I've actually been meaning to try google wallet (pretty much everywhere visa/mc tap to pay and apple pay are available too) for some time, and just never think to do it... when I saw the coin card, I thought it was an interesting idea, but to be honest, I think having something along with your phone is probably more useful, since anyone with a coin card is likely to also have their phone.
martingordon 11y ago
Even worse, I've had servers flat out refuse to accept it. I couldn't even imagine opening a tab at a bar with it either: It looks too fake to be taken as collateral, and I don't know if the magnetic strip still works if the card is locked, meaning I would have to have another round-trip interaction with the bartender.

stephengillie 11y ago

What Coin has managed to do in such a thin package is really impressive. It’s a shame they weren’t able to do it more reliably. 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)?

jaboutboul 11y ago
It would have been nice if they shared any of that info. Maybe more of us would be more sympathetic.
pjc50 11y ago
I suspect flexing the PCB caused the usual problems of hairline cracks in solder joints, resulting in intermittent faults.
- thaumaturgy 11y ago
  If that's true, I wonder if something like a paper circuit would work? e.g., http://www.instructables.com/id/Paperduino-20-with-Circuit-Scribe/ http://www.instructables.com/id/Paperduino-20-with-Circuit-S...
  - pjc50 11y ago
    Flexible substrates are not a problem - the industrial solution is polyimide (Kapton) or just really thin FR4. The problem is inflexible components. As soon as you bend a curved surface attached to a small flat rectangle (IC), it pulls at the joins. 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.
ngoel36 11y ago
Very often, the merchant would just assume I was using an Amex e.g. Amex Black....even though the display read VISA. This, of course, caused a decline...not worth the trouble to argue.

treycopeland 11y ago

I received my Coin about 2 months ago. I was excited to test it out after preordering almost 2 years in advance. The concept of having all my cards on one central card was a great idea. But having it not work at some locations was rather embarrassing and frustrating. I have decided the Coin was a fail and I will not carry it anymore. But, Coin, keep innovating. You tried.

lvs 11y ago
It sounds like just another startup hardware offering with a spotty launch. But I've always been confused about the perceived "embarrassment" of a card not working at the point of a transaction. This seems to be a common marketing trope in payments, but I don't know what it comes from. It's a piece of technology, and tech often doesn't work quite right. Sometimes my phone restarts itself. What's the big deal?
- j_s 11y ago
  Assuming the point was to aggregate the cards, if the one payment option you brought doesn't work... Personally, I will often leave any alternatives to the one payment method I intend to use locked in my car.
- GauntletWizard 11y ago
  It wastes your time, it wastes the cashier's time. It wastes the time of the people in line behind you. Isn't wasting people's time embarrassing? 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.
- mildweed 11y ago
  The line behind me wondering why I'm not done yet. Also, by using a Coin, I'm positioning myself as somebody who uses great, new technology. When that fails, it reflects poorly on me. Now I'm the guy who spends money on something that doesn't work, but keeps brandishing it, perhaps for some ego reason.
- 11y ago

myth_buster 11y ago

I'm curious to know whether given proliferation of the NFC alternatives available now like Apple/Google Pay is there a problem that Coin Card addresses which the former don't. Is paying in the restaurants one of those use case or will we see table side point-of-payments in near future which would make it obsolete.

fluidcruft 11y ago
For what it's worth, all of my banks have already replaced my credit cards with chip-and-pin capable ones in preparation for October's rebalancing of fraud liability between merchants and banks. I can't imagine merchants will be too keen to accept these Coin cards.
- gambiting 11y ago
  Pretty much nobody accepts signature-only cards in UK, it's all chip and pin now. I am sure US will follow suit soon.
- dboreham 11y ago
  Are you sure? I ask because the majority of US card issuers have opted to use chip&signature, not chip&pin cards. In my wallet I only have one chip&pin card (Well Fargo). The rest are chip&signature. Whether or not they send you a PIN is a good indicator of which auth method the card supports.
  - fluidcruft 11y ago
    Hmm. Perhaps not... I hadn't heard of chip & signature until your comment. I set the pin online during card activation, and hadn't thought about it closely. So, it obviously must be chip & signature. 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.
  - jonknee 11y ago

tdicola 11y ago

> It doesn’t look like there are many other products using the 51822 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 https://en.wikipedia.org/wiki/Micro_Bit

mik3y 11y ago
How's the toolchain support / dev environment for the Nordic parts these days? I remember the "other" popular chips (TI CC2540 and friends) had a gross and expensive requirement on "IAR Workbench".
- tdicola 11y ago
  Luckily GCC works great with it as it's an ARM Cortex M0. I use the GCC ARM embedded toolchain here and haven't had issues: https://launchpad.net/gcc-arm-embedded https://launchpad.net/gcc-arm-embedded The only gotcha is that you need to sign up with an account on Nordic's site to get access to their SDK and libraries, however I'm pretty sure that's just a formality and it's free to sign up (just can't distribute its firmware source, etc).

Globz 11y ago

This is the first time I am reading about this product but why mag stripe over smart cards? isn't it less secure and deprecated technology? it seems very useful but relying on mag stripe isn't the best move, no? Perhaps they couldn't "switch cards" while using smart cards so mag stripe was the only solution?

stephengillie 11y ago
In the USA, magnetic swipe readers are EVERYwhere. And the collection of credit and debit networks connect every reader with almost every bank. It "just works" everywhere, and it's "impossible" for a retailer to be unable to connect to your bank. -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.
- mbreese 11y ago
  Mag stripe readers are everywhere, but the banks have already started migrating over to chip and pin cards (with mag-stripe for backwards compatibility) for new issues. There are still older cards out there that won't expire for probably ~5 years or so, so I expect to see mag stripe readers around for at least that long. But it's fair to call it deprecated, even in the US. 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.
  - joezydeco 11y ago
    Target has very quietly replaced all of their terminals with chip/pin readers. It looks like they started shortly after their huge data breach, which makes sense.

dougb 11y ago

Coin is an interesting idea, but I figured https://www.dynamicsinc.com/ https://www.dynamicsinc.com/ would sue the pants off of them for patent infringement once they went to market. Dynamics CEO is a former patent attorney. dynamics seemed to have all the pieces in place to do the same thing.

nadams 11y ago

Was I the only one who canceled their pre-order after they asked for your social security number?

jackreichert 11y ago
I cancelled my preorder after I got the app and saw that silly tapping security code. I decided to try out Plastc after that. We'll see what that's like.
- mildweed 11y ago
  After being burnt by Coin at $50, I'm not jumping at the chance to waste $150 with Plastc.
  - jackreichert 11y ago
    I hear you, I got my $50 refund, got some credit for finding a share link for Plastc and felt $100 was worth it for my single attempt at using the tech.
cgriswald 11y ago
Nope. And I was offered the chance to get the beta or wait for the real thing. I opted for the beta and never received either. The app when pressed would tell me "just wait it's coming"

yrral 11y ago

Fcc photos of the coin pcb here [1] 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 https://fccid.io/document.php?id=2397353 [2] https://support.onlycoin.com/hc/en-us/articles/204263414-Coin-Compatibility 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.

mildweed 11y ago
I certainly have been rejected because of the lack of Track 1 data. One merchant told me as much.
joezydeco 11y ago
It seems like a logical thing to do, especially when you're trying to a) save power and b) time the speed of the coil's "stripes" to make the reader think it's seeing a physical card. It's probably also the source of a lot of rejected swipes. 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.

ngoel36 11y ago

I was so damn excited to use my Coin - the idea was brilliant. I tried to so hard to use it, but with a 30%+ failure rate, it became completely useless. Simply not worth the embarrassing "Sir, your card didn't work" or "Is this real?". And if I have to carry backups anyways, what's the point?

BrentOzar 11y ago
I like it because it got me down from several cards (debit, credit card A, credit card B, business card, business debit card) to two (debit card, Coin). The debit card is my backup to Coin.
- ngoel36 11y ago
  I formerly did the same, but it became insufficient. 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?

upofadown 11y ago

>I was surprised by the number of test pads exposed on the Coin - all those small metallic squares are programing points / test points. This suggests to me that Coin is still going though some debugging since it’s rare to see so many pads still exposed on a shipping product. 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.

ceequof 11y ago

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 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.

Dylan16807 11y ago
Lithium is not lithium ion. Single-use lithium batteries are made in a variety of voltages. This chemistry is in fact three volts.
- ceequof 11y ago
  Whoops, guess I'm wrong.

deegles 11y ago

Does cloning your card to a Coin make you liable for fraudulent transactions? I assume it would be against the ToS for most cards to allow cloning.

concerned_user 11y ago
That is what signature is for, isn't it? If bank can't prove it is your signature then it is a fraudulent transaction. Technically cashier/clerk should not accept the transaction if signature doesn't match but I've rarely seen them check it.

scoot 11y ago

If the mag-stripe emulation is just a simple electromagnet, I'm curious how they detected the position of the read-head in order to modulate the magnet correctly to emulate the data that would otherwise be read at that point of a traditional mag-stripe. Or is it more sophisticated still?

msandford 11y ago
My guess is that this is why they have so many problems. I'd guess that there's probably an accelerometer somewhere to give them an idea of what the swipe velocity is, so they can know how fast to play everything back. 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.
- joezydeco 11y ago
  Doesn't seem to be any accelerometers anywhere. There are two hidden membrane switches to either side of the coils. The card is probably using the press and release timing of that button as it travels through the reader to guess at the speed of the physical card. 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.

jackmaney 11y ago

I'm amazed that this idea actually caught on in the first place. "Wait, you mean I can put every single source of (non-cash) money in a single card, for a single point of failure? And if it breaks, I'm effectively penniless? WHERE THE FUCK DO I SIGN UP?!"

concerned_user 11y ago
Also imagine it gets stolen, good luck remembering all the cards you had in there and banks you need to call. Payment gateway route, like paypal, gives same convenience and less headaches.

dimino 11y ago

My Google Wallet card does the same thing this does.

jtchang 11y ago

I actually have the Nordic NRF51822 / NRF51 development board and it is super fun to play with. I come from a web dev background so getting into hardware is rough. 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.

sciencesama 11y ago

can we make eddystone beacon from this chip http://www.aliexpress.com/store/product/Bluetooth-4-0-BLE-Bluetooth-Low-Energy-CC2540-chip-Module-Iphone-4S/417006_819192101.html http://www.aliexpress.com/store/product/Bluetooth-4-0-BLE-Bl...

leybzon 11y ago
feels like it should be possible Eddystone is just a message format Some embedded coding skills will be needed thou