[HN Gopher] Building a panel out of e-ink electronic shelf labels
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Building a panel out of e-ink electronic shelf labels
Author : frxx
Score : 203 points
Date : 2022-08-02 08:23 UTC (14 hours ago)
(HTM) web link (rbaron.net)
(TXT) w3m dump (rbaron.net)
| jgrahamc wrote:
| I love stuff like this. I once went way too far down a rabbit
| hole with addressable Christmas lights.
|
| https://blog.jgc.org/2011/11/turning-ge-color-effects-g-35-c...
|
| These are also serially linked but the first step is to give each
| lamp an address and then messages just get passed on until
| consumed by the appropriate lamp.
| jacquesm wrote:
| That's really neat! I wonder if (and how long) they would run off
| a supercap or harvested wifi energy.
| [deleted]
| solarkraft wrote:
| This is cool. I like E-Ink displays and also have plans to build
| a wireless display like this, but was/am stuck on how to receive
| data while also sleeping as deeply as possible, so the linked
| page about advertising looks helpful!
| uptime wrote:
| Just came to say that I am loving rbaron's write ups - thank you
| introducing me to them @frxx.
| frxx wrote:
| I stumbled across them today. Glad I could make your day
| better.
| londons_explore wrote:
| I never quite understood why shops use those electronic shelf
| labels.
|
| Most of them _can 't_ be updated by someone in the store
| headquarters remotely. Someone has to take a bluetooth programmer
| device around and program each one by hand. And if they're doing
| that, they might as well just take a handheld label printer or
| sheet of labels.
|
| Benefit of the labels is they're clearer than e-ink, brighter,
| and more colorful (more sales)
| tiagod wrote:
| These labels have big readability issues, but the LCD ones are
| the absolute worse. There's a supermarket that uses them and I
| never go there as the prices are so hard to read, even at a
| perfect 90o angle, and especially the smaller price per
| weight/volume numbers...
| londons_explore wrote:
| Maybe it's deliberate...? Shops prefer shoppers to just buy
| the most prominent item rather than hunting around for a
| bargain... After all, the bargain items tend not to have a
| very high margin.
| npteljes wrote:
| I think of these as helpful side effects. It might not have
| been an explicit goal, but they sure as hell don't mind it.
| nerdjon wrote:
| I always assumed that any stores using these had them networked
| together.
|
| So the argument being that they don't have to pay someone to go
| around and update it and instead can just do it centrally?
|
| I think the Amazon stores do this, and I would assume that if
| anyone Amazon would set that up properly.
|
| I also thought I saw somewhere the idea that the displays let
| them tinker with the price more often instead of on a weekly
| basis when the flyers come out.
| MarkCole wrote:
| Usually for big supermarkets they are changed over a radio
| frequency. So they do not need people to go around and manually
| program them.
|
| You can also do cool time limited actions without having an
| employee go and manually change prices. For example in Kaufland
| stores in Germany at 19:00 the price of the Fruit and
| Vegetables is automatically reduced.
| dfxm12 wrote:
| _You can also do cool time limited actions_
|
| I would hate to put something in my cart that was $5 at the
| time I put it into my cart only to have it be $8 by the time
| I get to the till.
| ChuckNorris89 wrote:
| That's not how time limited actions work.
|
| In most of Europe at least there are strict laws on pricing
| so if you make a discount, it can't just time out after 10
| minutes, it needs to last the end of the business day or
| until the stock is depleted.
|
| These stric pricing regulations is probably why electronic
| shelf labels were invented in Europe, to make sure there
| will be no discrepancy between the price on the
| shelf/discount and the price on the register, otherwise the
| store is liable.
| londons_explore wrote:
| Which in turn makes dynamic pricing even less attractive
| for the shop.
|
| If they decrease the price, then there are some shoppers
| with the item currently in their cart who will pay less
| for the item than they expected to pay.
|
| But the reverse is disallowed by law.
|
| Which means that for every price change, the shop
| effectively loses out a little. Better not change prices
| too frequently!
| nicoburns wrote:
| The idea is to do a discount towards the end of the day
| to help clear stock that would otherwise go to waste
| because it has a short shelf life. Supermarkets do this
| all the time, but it generally involves an employee going
| around manually relabelling produce.
| ChuckNorris89 wrote:
| _> Most of them can't be updated by someone in the store
| headquarters remotely._
|
| Yest they _can_ , since the '90s (in Europe at least). Where
| did you get this misinformation?
|
| The programing device you saw is only for initial pairing or
| resetting the label, but other than that, they can always be
| updated via 2.4GHz radio or infrared base-stations (depending
| on manufacturer) mounted throughout the shop.
|
| Source: used to work in the industry many, many years ago
| ta988 wrote:
| In the store I worked in decades ago they were (LCD not e-ink)
| updated by two means IR and radio. Not sure why it had both.
| They were also kind of an ecological disaster. Getting crushed
| in the back of the store, tons of batteries... We probably
| replaced tens of them every freaking day (really large store).
| azinman2 wrote:
| batteries for eInk will last much, much longer.
| londons_explore wrote:
| I notice that the electronic labels are more common in poorer
| countries. Perhaps they help prevent fraud in some way (eg.
| shop assistant 'accidentally' misprices an item, and then their
| friend buys it?)
| kotaKat wrote:
| I've witnessed quite a lot of them using IR-based beacons
| installed on the ceiling, as well as a few of them that use an
| expansion slot on certain Cisco APs to piggyback a transmitter
| to change tags.
| spoonjim wrote:
| I can tell you that I have information indicating that RIGHT
| NOW major American retailers are losing LARGE amounts of money
| in stores where they don't have electronic tags. There is
| simply not enough labor to keep pace with price tag changes
| given the inflation.
| aiisjustanif wrote:
| Is it less wasteful than throwing away labels?
| londons_explore wrote:
| They only last 5 years. The an electronic label has to cost
| more both environmentally and financially than ~500 paper
| labels.
| nicoburns wrote:
| What's the failure mode?
| HeyLaughingBoy wrote:
| Well, I don't know about environmentally, but nothing
| suggests that they cost more (financially) than paper
| labels. If there wasn't an overall benefit, why would the
| stores use them?
| tiagod wrote:
| I doubt it, especially as they're not going to keep these
| labels forever. I would be interested is seeing real numbers,
| but I would bet you'd need A LOT of price changes to a
| product to offset the (monetary, carbon, ...) cost of the
| electronic label.
| bradfa wrote:
| It depends on how often you change prices, how many stores
| you have, and where the paper labels would be printed. For
| many stores now who have an online and physical presence
| where there's constant price pressures from all sides may
| change prices every day or even more often than that. The
| cost of the electronic label can be significantly less than
| printing labels, shipping them, then paying a worker in
| every store to manually change them.
| dawnerd wrote:
| BestBuys are pretty bright and they support red for sales. They
| can also show stock and additional info about the product.
| Really nice actually.
| wzdd wrote:
| Love the simplicity of the circuit with the daisy-chained uart
| lines and the use of a time-to-live counter to determine the
| target so you don't need to give each one an ID.
| tiagod wrote:
| Another approach to this, seen in addressable LED strips, is to
| have two commands - SET and RESET - where the first call to SET
| after a RESET will change the LED colour, and the next ones
| will just pass the value to the next node. RESETs will always
| be passed to the next node, resetting the whole strip. This
| doesn't require the hop counter.
| RL_Quine wrote:
| The APA102 is probably even simpler, it acts as a 1 byte
| shift register register per LED and passes the bytes down the
| chain without needing to really know the total length,
| there's some special case to latch all the data into the
| output registers. I'm fond of that design because it needs no
| timing specific input, you could easily input the data with
| push buttons if you cared to.
| sowbug wrote:
| GE Color Effects G-35 Christmas lights from about a decade
| ago used a similar scheme, except that they boot up in an
| "enumerate" state and use the first transmission to each
| figure out their own unique address (or pass the messages
| down the line). After that, they can each be addressed
| individually.
|
| (Edit: jgrahamc beat me to it!)
| solarkraft wrote:
| I'm super interested in these ESL displays, but couldn't really
| find any (the few I found are very expensive per piece).
|
| Are there any special keywords or sources for finding them in
| Europe?
| Moosdijk wrote:
| What a coincidence that this [1] popped up in my youtube feed
| today.
|
| [1]https://youtu.be/CLmotCeMlq0
| ryanmercer wrote:
| I'd run it off of a LiFePO4 (bioenno or something), but that's
| the ham in me (also I'd probably give it powerpole connectors
| just to further justify how much I spent on my crimpers haha).
|
| Really cool!
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(page generated 2022-08-02 23:01 UTC)