Hacking Electronic Price Tags

Something new is coming to a store near you: electronic price tags. [deadbird] decided to get one and see what makes it tick. First off it just looks like an LCD with some coin batteries and a simple board, but removing the batteries it was found that the text still appeared on the screen meaning its an E-Ink display.

Close examination of the chips on board shows that this model has an ATMEL ATMEGA16L, and a ATMEL952 25128AN (a 128k eprom with SPI interface), which makes this thing possible to bend to ones will. Also, dumping the eprom with an Arduino gets everyone a bit closer to decoding the instructions this thing needs to display its graphics, similar to the HP VFD hack we posted about not too long ago.

We have not seen these yet in our local shops, but give it time and it is bound to start popping up in our favorite surplus locations soon enough.

66 thoughts on “Hacking Electronic Price Tags

  1. My local Kohl(s) have been using a bit simpler version (just the price tag, no bar code, no text, LCD) for years now, mostly in shoes department.

    Never opened one though :)

    I’ve also seen a similar device (although for different use) where each one gets a very simple receiver embedded (like for a alpha pagers), with unique ID, then you update the information (the price tag) using a basic alpha paging setup.

    When you think further, just putting an old fashioned pager instead and subscribing to some cheap paging service, gets you in business quickly :)

    1. I disassembled one of these, the uC is in black epoxy and there was an antenna inside. I assume they broadcast RF with a serial number to wake up a particular tag for update.

      I’ve seen IR-updateable LCD tags in Germanys grocery stores over 10 years ago so yeah these are hardly new, but the e-ink one with what looks like a full graphic display is neat!

  2. They are all over Kohl’s Department Stores.

    Not sure what area they serve (but they are in Washington state) and nearly EVERY display has them, so hundreds in one store. :D

    However, I’m not sure if the ones in Kohl’s Department Stores are e-ink… they appear to be more like a watch led. (same size though), but I could be wrong.

  3. Verkkokauppa.com has similar tags in its retail shops. They are wireless and they show the price, SKU and how many items there are in the shop. They aren’t e-ink (yet).

  4. This was one of the original reasons for making e-ink displays. Tonnes of time is spend updating all the signage in store. Back when I worked retail it wasn’t uncommon to get pages of $0.01 price changes one day and then have them all go back the next. Being able to update them automatically would be a huge time saver, but then e-inks first came out it was too expensive an alternative. It’s nice to see that it’s actually being used for this now.

  5. Yep, the Kohl’s here in Atlanta use them for the shoe department. E-ink displays would be great fun to play with if they could be had easily or cheaply. I wonder if they ever “break” at the stores. Maybe they could be snagged before being thrown away.

  6. The Pricer electronic tags are interesting too, they have photodiodes to receive updates from high power IR projectors mounted in a grid array on the shop’s ceiling. They can be seen hanging from small pipes, and seem to have quite a few smd LEDs, reflectors, and also an ethernet connection.

    I stuck an IR logger under a shelf to see if it can record any update frames… According to one of their patentes, each store and each tag as a serial number. I’m wondering if the protocol is simple enough to start blanking tags out or writing random data to them :]

  7. I actually saw something similar in france about a year ago at a “geant casino” supermarket. They were normal lcd’s though and they have an receiver inside so i think they can remotely be changed.

  8. Disposible I thought they would be used for the shelf not on each individual item. The cost to use these on some items would probably be more than the item. But if you have it sitting under the item attached to the shelf showing what the product is worth that would be way worth it. Lots of the stuff at the grocery store(at least here) has their items marked that way.

  9. Am I the only one that though “Crap… now they can change the price of stuff automatically with supply/demand.” It could be interesting or it could be really sucky if they began tying sales to certain times of day or fiddling with prices on a daily basis. At least with paper tags, one can expect most things to stay pretty steady simply because the logistics of relabeling things gets in the way of changing prices too often.

    Also, this opens a whole new field of potentially fun hacking. An bakery section re-labeled with “the cake is a lie” comes to mind :-)

  10. @M4CGYV3R
    It might seem over the top, but consider how much paper and time is taken up with the continuous process of keeping pricing tags current?

    Imagine this in a large supermarket where 50 or so promotions could change each week.

  11. @M4CGYV3R
    I’m sure someone has determined it saves money. Otherwise they wouldn’t do it. Retail is usually very frugal as the profit margins are tight. Think about it, some supermarket chains make money only because they pay their suppliers one or two months later.

  12. Just wait til one day a cracker is in bad mood and start programing every tag to show random price.

    This remind me of a comic I read years ago. A kid found rolls of 20%/30%/40%/50% etc off stickers and started putting on random items….

  13. hmm, seems it would be easier not to tag every item, but have a set display that has their price, like how a supermarket has the price of items on the end of the shelf, not on the actually items.

    That would make it easy to update, not need as many, and the chances of peeps walking off with them are probably going to be slimmer.

  14. Here in france there are in nearly every supermarked. They could be indeed a great source for e-ink displays. A few of them could make a e-book reader.
    I think I need to try to get one.

  15. So, I managed to tear a couple of these small black tags from my Kohl’s to mess with them and find out what makes them tick. I’ve completely taken it apart, and cannot find a way to reprogram what to display on the tag. Removing the battery causes the display to cycle through its reset procedure endlessly. There are four holes next to the battery, but after using a safety pin to feel around, realize they’re not buttons, they’re just….random holes. So, any insight on the matter?

  16. @Budgethack
    That is genious. However, I guess this would only work on fluorescent lighting – most stores I know of use sodium or other high pressure discharge lighting (or halogen)…
    When I worked in retail we had about 40 prices a day to update. It was usually so hectic I only bothered updating the price increases and deft the decreases since it was just a nice surprise for the shopper :-)

  17. These things update from a central control unit via rf , allowing store wide price changes nearly instantaneously. Personally, I think your obsession with hacking everything goes to far. I can’t see any legit uses for someone other than the store owners to be able to control these devices. Sometimes you guys should just fuck off.

  18. Lets look at that for a moment. Unrestrained knowledge. The Japanese are wrestling with that very consequence right now. Just promise to show any pictures of you in court after you get arrested for the consequences of one of your hacks. I’d particularly like to see a picture of someone with a little tear coming out of the corner of their eye when the judge passes sentence.

  19. Let’s take a look at your statement. The people who have revolutionized energy output and technology advancement, intelligent minds who have had a hand in shaping the cush lifestyle you have come to know and love, innocent people just wanting to live another day…and you say they deserve the tragedy they are in right now? Get the fuck out of here, guy. Get out and stay in your goddamn bubble of ignorance. There are plenty like you, but you ruin the knowledge-economy for everyone when pieces of shit like you venture forth from your stupidity constructs.

  20. At first glance, this seemed like a needlessly expensive, easily exploitable system – However;

    I currently work for a regional gas-station/minimart chain – Every week, there are price changes and every month there are rolling specials. About 50% of the items in the store remain static, but every price change means that SOMEONE has to take the sticker sheets, print the new tags, go through the store and see which items are actually at our particular location, pull the old tag and put the new one up. Then, hope that the updates to the registers were timed correctly and that the tag you just put up is what rings up on the register…

    …This in mind, sticker-sheets aren’t cheap. Our time, though relatively cheap, could be better spent doing something else. Couple that with the fact that price changes and register updates coincide only ~10% of the time, and you’ve got a system that could benefit from these tags…

    …Think about it – Every day, the register system updates – At the same time, every electronic tag updates to show the new or current prices… Instant integration, no wasted time, and with how cheaply these things could be made outfitting an entire store could more than pay for itself in a year or less.

    -Now the cheapskate side comes out – In NY, our laws state that whatever the tag says is the price the customer is obligated to pay – If it rings up cheaper, nobody cares (though it costs the company)…If it rings up more expensive, I check the tag out – If the customer read it right, and the tag was truly made in error, I am obligated to sell it for the price on the tag. For a system like this to work, a system-wide update option, or a simple hand-scanner type “reset” must be available – Anyone who knows how could simply change the price on the tag, tell the cashier “that’s not what the tag says,” and get their merchandise at a discount…Logistics would need to be worked out, but one could get a good run before arousing suspicion…

  21. I noticed that there’s no cell phone coverage in Kohl’s. When walking out of Kohl’s, full bars. I have verizon. Sprint was a problem also with my friend. Could the RF device be blasting our cell phones out of coverage? If so, what range of RF are they blasting out

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