The tiny chip that powers Montreal subway tickets • Hacker News Board

Re: The tiny chip that powers Montreal subway tickets

#101

Post by dheera » Sun, Jun 23, 2024, 9:15 PM UTC

b112 wrote: post #53

dheera wrote: post #35

Earlier quoted context omitted.

I feel like 99% of people would not benefit from single use public transportation tickets. Even if you are a tourist, if you use public transportation once, there is a high likelihood you will use it multiple more times, in which case it makes sense to get a regular card. Most systems let you return the card and get the deposit back if you'd like. Personally I collect the cards instead because I have a tendency to re…

I don't know how many times I've been in a city for a single day, or part of one, and have zero interest in spending precious minutes finding, buying, and returning a card. Just let me pay with coins, or a credit card in seconds, with no return work.

I believe Singapore's public transit does support tapping a credit card directly at the gates now, but there's an annoying step of having to register your card in advance on an app before it actually works.

My guess is this might be because on-the-fly credit card authorizations still take too long. Waiting 3 seconds for an EMV contactless verification would seriously hold up the line at rush hour in a country where most people live by public transit.

If I were to guess, the registration is probably what enables them to pre-authorize a credit line and allow you to tap in in a fraction of a second.

Re: The tiny chip that powers Montreal subway tickets

#102

Post by [deleted] » Sun, Jun 23, 2024, 9:20 PM UTC

markus_zhang wrote: post #98

justusthane wrote: post #21

This is fascinating. We were just in Europe where we experienced these tickets for the first time. I had trouble with them; I was trying to figure out how to scan them because it never occurred to me that they might contain an NFC chip. My wife, on the other hand, who is not at all technical, took it for granted that you would tap them and immediately figured it out intuitively.

I have found the same thing with my wife. I'm a technical person, but I'm extremely bad with tools and such, including the ticket thing. If no one shows me how to use it I'll probably figure out a way to insert it somewhere. My wife won't have any problem with this and other small tools. The same thing with IKEA: I always rely on the manual and just blindly follow the instructions, and gets very frustrated if the ins…

[deleted]

Re: The tiny chip that powers Montreal subway tickets

#103

Post by rwmj » Sun, Jun 23, 2024, 9:24 PM UTC

kens wrote: post #90

Nition wrote: post #78

How is a chip like this actually manufactured? Especially the analogue components area.

It's manufactured pretty much the same as any other chip, using photolithography. Most of the analog components would be CMOS transistors, just larger. They might use a BiCMOS process with a few extra steps to make bipolar transistors. And there might be an extra step for the capacitors. But overall, the chip uses an old, simple manufacturing process, much easier than cutting-edge processors.

The chip seems like it's almost too small? I don't even know how they would cut up the wafer and how they would pick each die and mount it in the paper card.

Re: The tiny chip that powers Montreal subway tickets

#104

Post by kens » Sun, Jun 23, 2024, 9:25 PM UTC

teruakohatu wrote: post #99

kens wrote: post #2

Author here for all your NFC chip questions :-)

That was a god read, thank you. Do you have any insight into the economics of this in general compared to other disposable solutions. Are manufacturing old school magnetic stripe tickets, or just optical scanning/barcodes a lot cheaper? I imagine magnetic stripes have a higher failure to read rate at the turnstile causing issues, while both them and optical scanning requires the ticket to be inserted into the machine…

I couldn't find a nice price breakdown. I'd expect the magnetic stripe tickets to be cheaper to manufacture, but since the NFC tickets cost pennies, there isn't a lot of money to save. I agree with you that magnetic stripes would have a much higher maintenance cost due to the mechanical aspect and the read/write head. Optical scanning seems less likely to work the first time, based on my experience with airplane checkins. NFC is probably the best from an ecosystem perspective since it can work with credit cards and phones as well. NFC readers are probably the cheapest since they are produced in large volumes for credit card point of sale.

Re: The tiny chip that powers Montreal subway tickets

#105

Post by TacticalCoder » Sun, Jun 23, 2024, 9:26 PM UTC

marssaxman wrote: post #69

justusthane wrote: post #21

This is fascinating. We were just in Europe where we experienced these tickets for the first time. I had trouble with them; I was trying to figure out how to scan them because it never occurred to me that they might contain an NFC chip. My wife, on the other hand, who is not at all technical, took it for granted that you would tap them and immediately figured it out intuitively.

That's funny - I'm sure I would have shared your confusion, as all tappable objects in my world are made of plastic. I wonder how your wife thought of it?

> ... as all tappable objects in my world are made of plastic

yup in mine plastic and metal but not paper.

Re: The tiny chip that powers Montreal subway tickets

#106

Post by TheJoeMan » Sun, Jun 23, 2024, 9:26 PM UTC

justusthane wrote: post #21

This is fascinating. We were just in Europe where we experienced these tickets for the first time. I had trouble with them; I was trying to figure out how to scan them because it never occurred to me that they might contain an NFC chip. My wife, on the other hand, who is not at all technical, took it for granted that you would tap them and immediately figured it out intuitively.

Does the card not have the three-arcs nfc symbol? Similar to the wifi symbol. To me the fake printed dip-chip is more confusing!

Re: The tiny chip that powers Montreal subway tickets

#107

Post by kens » Sun, Jun 23, 2024, 9:27 PM UTC

astrobe_ wrote: post #57

kens wrote: post #10

Earlier quoted context omitted.

I think this chip is implemented with a state machine rather than a processor, so it's meaningless to compare their processing power. The Apollo Guidance Computer had about 17,000 transistors, while I estimate that the NFC chip has about 45,000 transistors. So the NFC chip has more complexity, but the same order of magnitude.

For the fun of it, what about radiation hardening ?

The Apollo Guidance Computer would be more radiation-hard, due to its large transistors and magnetic core memory.

Re: The tiny chip that powers Montreal subway tickets

#108

Post by Sytten » Sun, Jun 23, 2024, 9:27 PM UTC

They are going away soon (TM), the tech is cool but they are impractical. I will be happy to use my credit card or phone.

Too many times I have been stuck in 15-20 minutes queues to buy those tickets and you cant refill them with an app... Plus south shore and north shore have they own system it's a mess.

Re: The tiny chip that powers Montreal subway tickets

#109

Post by kens » Sun, Jun 23, 2024, 9:29 PM UTC

TheJoeMan wrote: post #106

justusthane wrote: post #21

This is fascinating. We were just in Europe where we experienced these tickets for the first time. I had trouble with them; I was trying to figure out how to scan them because it never occurred to me that they might contain an NFC chip. My wife, on the other hand, who is not at all technical, took it for granted that you would tap them and immediately figured it out intuitively.

Does the card not have the three-arcs nfc symbol? Similar to the wifi symbol. To me the fake printed dip-chip is more confusing!

No, the card doesn't have any symbols like that. It does have a pictogram of the card getting tapped on a reader, along with the text "Apposez sur le lecteur".

Re: The tiny chip that powers Montreal subway tickets

#110

Post by Tijdreiziger » Sun, Jun 23, 2024, 9:36 PM UTC

ck45 wrote: post #70

stacktrust wrote: post #61

You can use these around the house or car for location-tap automation. Tap on NFC tag and mobile phone can trigger a custom shortcut for local action or SSH script to Linux SBC or micro PC. Response time is about one second. Even the iPhone SE2 has an NFC reader. For vision-impaired people, NFC tags can be attached to objects and the phone can read an audio description when the object is tapped against phone.

This reminds me a bit of Nabaztags, or maybe the reverse. They would also read something that resembles NFC and could perform an action.

Around that time, I recall there being a lot of hype around RFID tags. E.g. the Touchatag was just a bunch of RFID tags and a USB RFID reader, but marketed as a consumer product. This never really seems to have caught on, though.

Nowadays, I suppose most consumers do have RFID tags (debit cards, transport cards, building keys, e-Passports), they just might not be aware of the underlying technology.