EEVblog #687 - EFTPOS PIN Pad Terminal Teardown

[ovnr]

I really enjoy the 50fps stuff. Much nicer.

(Personally, I'd have upsampled everything to 60fps (at least for the mailbag, given that the main cam for that is apparently 60fps?), rather than downsample to 50. PCs have to repeat the same frame every 6 frames or so when playing 50 fps video.)



Anyhows! The top board with the unpopulated area is actually a DC/DC converter - see below. It's probably used for an optional battery-powered model.

[nitro2k01]

ovnr: See my comment above. The DC/DC is likely specific to the GPRS module.

[coppice]

I've read about that one before, and its bizarre. The critical silicon in machines like this are developed by trusted teams, in trusted labs.

This is all part fo the standard, which as I briefly mentioned included the handling and management of device as well.

So, what happened in that UK case? There was no mention of the Chinese contract manufacturer being a trusted assembly house who were compromised by criminals. They appear to have been just the average kind of contract assembly place, compromised by criminals. Were the standards ignored when that manufacturer was chosen, or are the holes in the standards?

[(In)Sanity]

You know what they say about opinions,  well here comes one.

I found myself fast forwarding until I actual could see some circuit board.  The beginning of this video was "as boring as bat shit".    I love tear down video's,  they rock.  This one,  not so much.   I'll admit it got better toward the end.   

Find some more test gear to tear apart,  something people might actually own or can relate to.   

Things not to tear apart:   Cell phones,  calculators,  remote controls,   etc.   If it doesn't have a power supply inside..it might end up just being boring.    Survey the populous,  find out what kinds of stuff people want to see.

Hey,  just my two cents. 

Jeff

[nitro2k01]

Things not to tear apart:   Cell phones,  calculators,  remote controls,   etc.   

I don't really agree. Such simple things don't necessarily need a one hour waffle session, but they are excellent for some historical context, ie an example of electronics design used to be like. A quick look inside even a simple item is often interesting in that you may notice some minor detail you didn't know about.

[(In)Sanity]

Things not to tear apart:   Cell phones,  calculators,  remote controls,   etc.   

I don't really agree. Such simple things don't necessarily need a one hour waffle session, but they are excellent for some historical context, ie an example of electronics design used to be like. A quick look inside even a simple item is often interesting in that you may notice some minor detail you didn't know about.

Ok,  I'll agree on that basis.  But yes let's not spend 30 minutes looking at stuff that's just become obsolete.   Now take apart the worlds first cell phone and that's great.   If it has historical value it's fair game.

Jeff 

[NickS]

The keypress recorder seems a lot harder to install. Any ideas?

Pull buttons out through their own hole. Just cut/tear the sillicon membrane and pray you don't dislodge the tamper one.

Then make your own individual buttons which look the same with a tap on each one, little bit of glue and push it in to the hole.
Do a neat job and no one would notice without looking closely.

[Angryfeet]

That unpopulated connector near the big exposed ground plane looks like a PCI connector, which would be used for the optional GPRS module. The unpopulated stuff on the other side is likely just power conversion for said module.

Yes, Sagem also make GRPS modules.

[coppice]

That unpopulated connector near the big exposed ground plane looks like a PCI connector, which would be used for the optional GPRS module. The unpopulated stuff on the other side is likely just power conversion for said module.

Yes, Sagem also make GRPS modules.

and GSM phones, and FAX machines, and utility meters and many other things. They have quite a low profile for a company with such a wide range of activities.

[phenol]

The printer inside has 384 pixels, 200dpi resolution, paper advance pitch is 0.0625mm, can print at almost 100mm/s ...still in production today

[G7PSK]

That unpopulated connector near the big exposed ground plane looks like a PCI connector, which would be used for the optional GPRS module. The unpopulated stuff on the other side is likely just power conversion for said module.

Yes, Sagem also make GRPS modules.

and GSM phones, and FAX machines, and utility meters and many other things. They have quite a low profile for a company with such a wide range of activities.

I had a Sagem fax machine, actually several as they had a habit of blowing up quite literally, I had to throw one out of the office window in flames. At the time in the 90's Sagem was part of the French Nuclear industry and as such state owned.

[senso]

Not a pin pad terminal, but also in the mood of the topic:

[Howardlong]

At 07:10.

Here ya go...



For black ends, use a silver calligraphy pen.

Overpaint with clear varnish, or pinch the wife's clear nail varnish.

[delmadord]

The printer inside has 384 pixels, 200dpi resolution, paper advance pitch is 0.0625mm, can print at almost 100mm/s ...still in production today

I am currently on a project involving one of these (or maybe similar, just thermal printer). How much effort it takes to get them running from a linux board, if they come from Alibaba (that means less change of proper datasheet), please?

[Fungus]

Here ya go...

For black ends, use a silver calligraphy pen.

Overpaint with clear varnish, or pinch the wife's clear nail varnish.

For that price you'd think they could print it on there for you...

[max666]

I know you didn't ask, but may I give you my opinion about your opinion =p
(I’m not intending to attack your opinion, just trying to represent others as well, in case Dave is watching)

...I found myself fast forwarding until I actual could see some circuit board.  The beginning of this video was "as boring as bat shit"....

Ok, I get you like seeing naked circuit board; well I enjoyed the foreplay. Not everyone is familiar with every devices Dave is tearing down, so some context on why things are the way they are can be quite helpful.

...,  something people might actually own or can relate to.  ...

But if you only watch teardowns of things you own or can relate to, wouldn't that just be a recipe for boring teardowns?

...  If it doesn't have a power supply inside..it might end up just being boring. ....

What is it about not having a power supply that makes a product inherently uninteresting? Especially since the power supply is probably the first thing that gets boring after you've seen one or two.

[(In)Sanity]

I know you didn't ask, but may I give you my opinion about your opinion =p
(I’m not intending to attack your opinion, just trying to represent others as well, in case Dave is watching)

...I found myself fast forwarding until I actual could see some circuit board.  The beginning of this video was "as boring as bat shit"....

Ok, I get you like seeing naked circuit board; well I enjoyed the foreplay. Not everyone is familiar with every devices Dave is tearing down, so some context on why things are the way they are can be quite helpful.

...,  something people might actually own or can relate to.  ...

But if you only watch teardowns of things you own or can relate to, wouldn't that just be a recipe for boring teardowns?

...  If it doesn't have a power supply inside..it might end up just being boring. ....

What is it about not having a power supply that makes a product inherently uninteresting? Especially since the power supply is probably the first thing that gets boring after you've seen one or two.

Devices with internal power supplies tend to be more complex and/or often analog in nature.  Seeing a device that consists of nothing but high density surface mount IC's and a few bypass caps is about as boring as it gets.   Even scope and spectrum analyzer tear downs have analog components and explanations that go along with that part of the circuit.   

Tear apart a modern PC,  what's the most interesting part of the entire thing,  the mufti-phase power supplies running the big boring chips.   The power supplies themselves and perhaps some thermal management.   

Cool stuff is stuff that can be broken down and explained,  not looking at an ASIC and saying..hey that does it all right in that one chip.    This is not to say Dave has done this,   at least not intentionally.   

I'm sure everyone has opinions about what they like and don't like to see,  I'm just expressing mine.    My favorite tear down video's so far I believe were the old analog scopes.   Blast from the past of something I don't own and that has character and substance.    My next favorite were the various power supply tear downs.   Looking at how they handle higher voltages and thermal management.

What's your favorite tear down ?

Jeff

[RobertHolcombe]

Sorry about the dodgy photos, I just took them quickly today while work was quiet. Two model PINPads from the same manufacturer, using essentially the same method of tamper detection. The first two pictures are an older model, we commonly replace them due to entering tamper mode, as well as the contactless/paywave readers failing - the RFID module attaches to the top of the PINPad, interfaces using a SD-card style connecter w/ flat-flex - fairly robust but ham-fisted operators would remove the PINPad from its cradle using the top module, stressing the interconnect and in some cases the mounting system itself, breaking the module. Derp.

[phenol]

The printer inside has 384 pixels, 200dpi resolution, paper advance pitch is 0.0625mm, can print at almost 100mm/s ...still in production today

I am currently on a project involving one of these (or maybe similar, just thermal printer). How much effort it takes to get them running from a linux board, if they come from Alibaba (that means less change of proper datasheet), please?

If this is the fist time you lay hands on a thermal printer, it won't be all that trivial. You'll probably toast the thermal head first thing you fire the strobes for more than a few ms. It is for this reason that thermal printer manufacturers also sell various chipset solutions, essentially a preprogrammed microcontroller as a bare chip to which you send ascii characters, graphics data and various control codes, and it takes proper care of driving the printer mechanism in the right way.

[SeanB]

Yes, and Epson has a range of printer interfaces that are basically a mask programmed 8052 with extra firmware to handle the printer using either a serial data or parallel data stream. You connect it, provide power and a clock crystal and send data and it does the rest. literally a single chip needing only a single ULN200x transistor array to drive the motors.

[delmadord]

If this is the fist time you lay hands on a thermal printer, it won't be all that trivial. You'll probably toast the thermal head first thing you fire the strobes for more than a few ms. It is for this reason that thermal printer manufacturers also sell various chipset solutions, essentially a preprogrammed microcontroller as a bare chip to which you send ascii characters, graphics data and various control codes, and it takes proper care of driving the printer mechanism in the right way.

Yes, and Epson has a range of printer interfaces that are basically a mask programmed 8052 with extra firmware to handle the printer using either a serial data or parallel data stream. You connect it, provide power and a clock crystal and send data and it does the rest. literally a single chip needing only a single ULN200x transistor array to drive the motors.

Yeah, thanks, I have already found some sellers on alibaba that sell the thermal printing header along with a board that requires just PWR, GND and two UART lines, will most likely roll this solution. The problem is custom enclosure, though, but it it not a matter of this thread anyway.

[phenol]

there are semi-integrated mechanisms out there, they call them bucket printers. a typical bucket consists of a simple mech like the one in that POS terminal with a plastic paper holder bucket around it. Typically those are panel-mount and have either their own driver board or space for one.
The chipsets and the driver boards normally have windows/linux/... drivers with them, which means that you can hook a thermal printer to your PC or whatever OS platform...

[plaes]

This "security locking tab or something like that" slot @ 4:30 is actually a window to see how much printer paper is left in the roll.

[Don Hills]

Many of these terminals can have built-in POTS modems for connectivity.
These are typically used by low-volume retailers who may only have a few transactions per hour. They often share a line with the retailer's main phone.
The modems are typically 1200 bps v.22 synchronous, using SDLC protocol.  Why 40 year old technology?
1200 bps makes perfect sense when you look at a typical EFTPOS transaction. Most transactions involve only a few hundred bytes of data transferred each way. A v.22 modem pair can be connected, default equalised, fast trained and into data mode in as little as half a second. So you can connect, transfer the data and disconnect before a faster modem would complete training (the bleeps and bloops you hear when a faster modem connects.) The number dialed is usually only 4 or 5 digits, and the terminal usually initiates the dial sequence as soon as the retailer initiates the transaction. By the time you swipe your card and enter the PIN, the connection is already made.

I'm less clear on why SDLC protocol. I suspect it goes back to the early days of online banking when IBM had a large share of the market in banking terminals and ATMs etc, and the networking was IBM's SNA which used SDLC as the layer 2 protocol.

[delmadord]

there are semi-integrated mechanisms out there, they call them bucket printers. a typical bucket consists of a simple mech like the one in that POS terminal with a plastic paper holder bucket around it. Typically those are panel-mount and have either their own driver board or space for one.
The chipsets and the driver boards normally have windows/linux/... drivers with them, which means that you can hook a thermal printer to your PC or whatever OS platform...

Thanks for noting, will probably start own thread for it, because I can imagine what you are talking about and it is surely interesting and useful, but cant find any on the internet right now.