Catch up on stories from the past week (and beyond) at the Slashdot story archive

 


Forgot your password?
Close
typodupeerror
×
Power Displays Hardware

7.5-Inch E-Ink Display Is Powered Completely By NFC (arstechnica.com) 49

Posted by BeauHD from the power-sipping dept.
An anonymous reader quotes a report from Ars Technica: NFC is usually only used to for quick text transfers, like a tap-and-pay transaction at a register or a quick data transfer from an NFC sticker. A company called "Waveshare" is really pushing the limits of NFC, though, with a 7.5-inch e-ink display that gets its data, and its power, from an NFC transfer. The $70 display doesn't have a battery and doesn't need a wired power connection. E-paper (or e-ink) displays have the unique property of not needing power to maintain an image. Once a charge blasts across the display and correctly aligns pixels full of black and white balls, everything will stay where it is when the power turns off, so the image will stick around. You might not have thought about it before, but in addition to data, NFC comes with a tiny wireless power transfer. This display is designed so that NFC provides just enough power to refresh the display during a data transfer, and the e-ink display will hold onto the image afterward.

NFC data transfers max out at a whopping 424 kbit/s. While that's enough for an instant transfer of credit card data or a URL, the 800x400 image the display needs will take several seconds. Waveshare says the display takes five seconds just to refresh, and that doesn't count the data transfer, which will vary depending on how complex your image is. The video shows a start-to-finish refresh that takes 10 seconds. If you want to use a phone, an Android app will convert your image into several different black-and-white styles and beam it to the display. Sadly, there's no iOS app yet. iOS apps didn't have the ability to write to NFC devices for the longest time. Writing to NFC was added with the launch of iOS 13, which only happened a few months ago.
This discussion has been archived. No new comments can be posted.

7.5-Inch E-Ink Display Is Powered Completely By NFC More

7.5-Inch E-Ink Display Is Powered Completely By NFC

Comments Filter:

  • NFC (Score:1)

    by Anonymous Coward

    Am I the only one who has No Fucking Clue what NFC means?

  • I really would like a nice cheap e-ink device instead of all the tablets I've accumulated.

    • How would that work? Each time you need to turn the page you'd need to pick up your phone, maybe unlock it and go to the app and say "next page", then wait for the upload/page refresh which takes quite a few seconds. Maybe you can somehow automate and keep the app running and the NFC scanning all the time on the phone but you'd still need to bring the phone to the ereader and wait for the upload.

      All that when a Kindle with a MUCH better display, wifi, storage, instant page flip compared to this plus back-li

      • This is definitely not for e-readers. It's for signs and displays that will remain static for a hours or days at a time between updates.

        Prices, hours, specials, directions, beers on tap, tonight's band, tomorrow's weather forecast...

        I could see dozens of these in public places like hotels, office buildings, schools... except the N in NFC stands for "near..." which means you have to place your phone on top of it for ~10 seconds, so you've got to send a dude around to every sign to update it. It's awesome t

        • This is definitely not for e-readers. It's for signs and displays that will remain static for a hours or days at a time between updates.

          Prices, hours, specials, directions, beers on tap, tonight's band, tomorrow's weather forecast...

          I could see dozens of these in public places like hotels, office buildings, schools... except the N in NFC stands for "near..." which means you have to place your phone on top of it for ~10 seconds, so you've got to send a dude around to every sign to update it. It's awesome they don't require power, and I'm sure there are lots of use cases... but they'll be pretty narrow use cases.

          The problem is that e-ink displays need to be refreshed quite often or they suffer from "burn-in". If you leave for weeks without a refresh then it's doing to develop really dirty whites.

          • The problem is that e-ink displays need to be refreshed quite often or they suffer from "burn-in". If you leave for weeks without a refresh then it's doing to develop really dirty whites.

            Do you have a source for this? I have three e-ink ebook readers, all of which go to some standard display when turned off, and I sometimes leave them off for weeks. I've never seen any "burn-in" on any of them.

  • NFC (Score:2)

    by glitch! ( 57276 )

    NFC is Near Field Communications. It is not really RFID. The reader, the active device, sends a carrier wave that the card can use for energy. The reader sends (modulates) commands on this carrier, and the card uses its antenna, processor, and transistor to selectively dampen the induced field. This is how they communicate bits.

  • I do a lot of repair work ( computers/electronics/laptops ) and one of the common pains is that when you take the device from the holding slot, you either have written notes, or a job-id that you then have to look up on the computers so you can catch up on what has happened so far with the repair. What I'm hoping this device will provide for me is a summary of the device situation for me to read when I check the slot and that I can wirelessly update at the end of the next time it's on the workbench bein

    • Seems useful for grocery store displays. Where you can mount 100 of them to shelves and update them while restocking them.

      • Rewe in Germany already has that.
        The prices sometimes update right in front of your fucking eyes!
        Like Amazon but only individualized to the location and the time/day.
        Fucking bastards.
        It's why I don't shop there unless I have to.

      • Re: (Score:2)

        by AmiMoJo ( 196126 )

        They already exist. The older ones were LCD based and use a battery or solar panel similar to a calculator. IR for programming from a terminal. Newer ones a epaper based but I don't know if they are still IR or if they moved to NFC.

    • You really just need software for this.

      You can get a $25 eink dev board that would do this just fine, including ones with wifi.

      • Re: (Score:2)

        by inflex ( 123318 )

        The key convenience here is the lack of battery/cables required. Sure, I could do it as a powered setup many other ways, but going with the NFC powered route ticks off the final item in the list I was waiting for.

        • Why is lack of cables a convenience when it is on a workbench?

          • Re: (Score:2)

            by inflex ( 123318 )

            Because it stays with the item under repair. Repairs often require multiple sessions on the workbench and moved between several staff. The idea is that this eInk device stays with the specific job as it's moved around between staff, workbenches and holding slots.

    • The market for this is really high end electronic price tags for retail. Update on the fly from a tablet or phone based ordering system is sort of becoming the 'next big thing' in retail. Theory is it saves thousands of dollars a year in replacing the little plastic and paper tags as prices change weekly, or even daily. we'll see if it pans out.

    • I do a lot of repair work ( computers/electronics/laptops ) and one of the common pains is that when you take the device from the holding slot, you either have written notes, or a job-id that you then have to look up on the computers so you can catch up on what has happened so far with the repair. What I'm hoping this device will provide for me is a summary of the device situation for me to read when I check the slot and that I can wirelessly update at the end of the next time it's on the workbench being further serviced (or completed).

      Seems like a lot of money to put towards what is little more than a fancy sticker or perhaps a sheet of paper but often in workflow situations it can be small things like that which make all the difference ( though $75 is still a lot of stickers/paper! )

      Barcode scanner on Android, or whatever, with a db backend, remember to backup your database(s)

      • Re: (Score:2)

        by inflex ( 123318 )

        Have just bought the dev unit, will see if it provides any real gains and solves the perceived itch. A bit of programming will be required, and maybe another NFC unit to make it work direct from PC (rather than their pc->bmp->sd->NFC), but it'll be a nice project, or a waste of $100 USD.

  • ...424 kbit/s. While that's enough for an instant transfer of credit card data or a URL, the 800x400 image the display needs will take several seconds. Waveshare says the display takes five seconds just to refresh, and that doesn't count the data transfer

    Probably shouldn't count the data transfer - you don't have to wait for the transfer to complete, you can start updating the display as the data arrives - not unlike CRTs.

    Especially if the data transfer is powering the screen refresh - in which case you'd ideally update the screen at the same speed as the data is transferred so that you don't have to store much power to finish the job. Possibly even throttling the transfer rate to ensure it takes long enough for the refresh to finish. Does NFC have some

    • Re: (Score:2)

      by fazig ( 2909523 )
      How many bits per pixel are required would depend on how the display is used.
      You can have grayscale by rotating the pixels to only show the black parts partially, which would require a certain bit depth per pixel. But you could use it as a monochrome display and 'fake' grayscale with dither that is done o the software side in your mobile device.

      In the Youtube ad they state that the display colour is "Black / White" and if you watch further you'll see them demonstrating a transfer of a coloured image to t

  • Will we get a display powered completely by the AFC?

  • That'll _definitely_ be a success!

  • For many years now, all the Kohl's stores have e-ink price tags - but cell-coin battery powered.
    Store employees were updating prices using a handheld ( Android phone in a bulky case with barcode reader )
    If the price of those is similar to the old battery-powered ones, they have a good market.

  • ... do we really need to demo cool new hardware by displaying anime pinups?

    • It is the decider's fetish.

      Had he had a foot fetish, we'd get barefoot girl.

      Would he have a car fetish, we'd get the latest Ferrari/Lamborghini/...

      By the way ... I wonder what deep anal foot fisting, guro and vore, *stops looking at old encyclopedia dramatica archive* and other fucked-up fetishists use instead. :)

    • Re: (Score:2)

      by rho ( 6063 )

      It's Arstechnica. Know your customer.

  • My printer!
    Make the paper come out between two panels of glass. No need for power to change the image either.
    And much faster!
    Sadly, only for the desktop. :)

  • Combine this with nonvolatile memory capable of being updated with NFC power and you've got something that can accumulate updated data. Makes it whole lot more useful.

  • Coronavirus (Score:1, Informative)

    by Malays2 bowman ( 6656916 )

    God forbid we have something in current news media that does not mention this /s

    I can't wait until the current PANIC (I won't say pandemic here) is over so everything can just fucking get back to normal.

      (Yes, awaiting mod-down, but I am fed up and angry right now)

  • Imagine a much smaller version of this being embedded into something like a RFID based transit pass card (like the "Tap" cards used in LA), and being able to see how many trips/remaining balance you have left
    on that card.

    I think it's very doable and I don't think it require the card to be much larger (maybe an extra mm or two) if they can lay out the display support components the same way as the RFID chip.

    I think the only real barrier is cost, but I would like to see this as an option for c

  • Read latest technical updates on technicalupdates.in

Slashdot Top Deals

New York... when civilization falls apart, remember, we were way ahead of you. - David Letterman

Close