There are plenty of lovely e-readers out on the market that come with an nice big e-paper display. There aren’t nearly as many that come with two. [Martin den Hoed] developed the Diptyx e-reader with such a design in order to better replicate the paper books of old.
The build is based around the ESP32-S3, a powerful microcontroller which comes with the benefit of having WiFi connectivity baked in. It’s hooked up to a pair of 648×480 e-paper displays, which are installed in a fold-open housing to create the impression that one is reading a traditional book. The displays themselves are driven with custom look-up tables to allow for low-latency updates when turning pages. The firmware of the device is inspired by the epub reader from [Atomic14], and can handle different fonts and line spacing without issue. Power is from a pair of 1,500 mAh lithium-polymer cells, which should keep the device running for a good long time, and they can be charged over USB-C like any modern gadget.
You can follow along with the project on the official website, or check it out on Crowd Supply if you’re so inclined. The project is intended to be open source, with files to be released once the design is finalized for an initial production run.
We’ve seen some great DIY e-reader builds over the years, and we’re loving the development we’re seeing in the writer deck space, too. If you’re whipping up something fun in this vein, be sure to let us know on the tipsline!
Lol, I recently had an even more extreme idea.
A physical kinda 1to1 replacement for a hardcover book.
TLDR: Basically some kind of ridiculous mechanical contraption where 4 double sided ePapper pages can be flipped like normal pages infinitely inside a normal looking book cover (+back & spine).
eight ePaper displays of the same size.
four book “pages” with two of 1. each (double sided ePaper “page”).
those four frames/”pages” go inside a (mechanical) real hardcover and can be flipped like normal pages.
depending on the flip direction one of the two then hidden “pages” moves to that part of the book were currently only one page resides.
Example (state flow?):
1. physically you start reading in the middle of the book. Two “pages” in either direction (1,2,youarehere,3,4).
2. you flip a page (1,2,3,youarehere,4).
3. while you do 2. (or once you are done) the book moves page 1 to the end (2,3,youarehere,4,1) and refreshes the displays with the new eBook pages.
4. reverse when you flip the other way.
Pretty useless but kinda perfect for HaD. :-)
(maaaaaaybe for some (extreme) mental/physical handicaps???)
Great, HaDs commenting system ate the first set of numbers (1. to 4.)
That’s the most over engineered solution for something so simple… And somehow I still live the idea.
That’s the silliest thing I’ve ever heard of. And where can I buy it? 😆
Always thought ereaders should always come with two sides, one – for taking notes, because flipping back and forth (or note-taking over the text) is okay, but not ideal. Some things, like serious textbook study, needs two sides of equal size, and (ideally) ability to screenshot parts of the other page.
Regardless, excellent project, I may consider copying.
my Boox ereader has a split-screen feature for this, among many other niceties including a fairly functional browser for those times when what you’re reading only exists as a webpage. not sure I could go back to a “dumb” ereader, and I’m a bit suspicious by the almost complete lack of footage of user interaction in their promo video-driving a responsive UI across two high density displays seems like a lot to ask of an esp32, no?
I’d be surprised if the esp32 couldn’t do it (if programmed properly) – everyone seems to forget how much you can get ‘close to bare metal’ hardware to do when not using 500 different library’s and an interpreted language..
The esp32 has roughly the same processing power as my university computer had back in the day..
You get very close to the limit due to low pin count and speed. You just don’t have the ability to drive multiple buses at high speed (say, 2 octal buses – no way you’ll be using any hardware accelerators) and IIRC only the ESP32-P4 has a graphics accelerator of some sort
I’ve seen many projects that use an ESP32 for specific features and an STM32 solely for display
Dual-core 200mHz CPU is no slouch! It can serve up streaming video, it should definitely be able to handle 2 low resolution screens of static text.
I’m not sure on which planet you’re living, but one tick every 5 seconds would be regarded as quite slowish for a microprocessor by nearly all people.
Two things. I do love this hack it’s a great design. I am curious how it’s wired across the hinge. It looks like it has a satisfying magnet snap.
Also Sammie Gee. I’ve wanted the same thing with regards to replacing a book plus a notepad for so long. If you ever find one or make one please put up a bat signal for me to find.
Roger that.
For now my priorities elsewhere (wrapping up all the 2025 projects – or binning the plans), but there are few 7 inch eInk screens that I was looking at in September (unrelated) that were within my budget. My thought train was “ESP32-P4 would probably easily drive more than two”.
I eventually went lazy and bought M5Stack’s Tab5, since it already had all the niceties included for trial-and-error projects. However, my original plan was Waveshare’s ESP32-P4-WIFI6 that has P4 and C6 AND two ribbon cable ports for plugging in camera and display. I am also quite sure with some code-wrangling I may convince P4 to drive two eInk displays instead, so there, the potential candidate for the board driving the two screens.
In the past I’ve managed to convince a lowly Arduino Nano to drive two graphic screens at once, though, the results were okay, not spectacular. I run into issue with switching the screen select fast enough for the screens to react in time, ie, half of the times the screens wouldn’t refresh on time and start showing random noise. At some point I just gave up figuring out why it does that and added second Nano for the second screen, both now running the same program (reading RTC and showing time in two different ways simultaneously). In the hindsight, I am sure adding some kind of latch-on circuit would fix the timing, but I had other projects that were more important. The idea remained, though, with some careful planning multiple screens off of one unit is not only possible, but completely doable.
Because it goes like this, if I can do two screens off of one unit, there is no reason I cannot stretch the same to do three or four screens. ESP32-P4 is actually quite a powerhouse, and slow-refresh eInk that doesn’t need absolute perfect timing is a good target to aim at.
I forget the name of the product, but I actually had a commercial Android tablet with an Emil screen on side, lcd on the other, hinged like the project. And software that could do a book on just eink, both, or use the lcd for synch’d notes. Just thick, older displays, and a bit slow. But useful! Got to see if I kept it in a drawer…
It would be amazing to see a firmware hack to link two Remarkable Pro Move size devices together to do this – be able to read across both, or take notes on one side and reference a doc on the other. They have the stylus/touch input packaging sorted out with a very slim overall thickness.
As nice as that is, my issue with clamshell electronics is the connecting cable. Invariably, that flexing back and forth is going to be the weakest link.
If you put a MCU with Bluetooth in both sides you could reduce the necessary cable to just power maybe?
You’d have two devices to charge, but… better than the ribbon cabal, for sure!
Nevermind… I just saw that yo were proposing to power it from the one side. Yeah… much better!
If they can power pc fans with contact pins, why can’t they share power charging from one port in the same way when the device is closed? There’s already a magnetic latch. I believe it’s called unit daisy chaining?
If you some sort of contact connector and a battery for that page only, it could transfer the page data only every time you closed and opened the book (flipped the page) and then the power port could be in the side with just the battery and screen and you could charge both of them while closed, because then the contacts could transfer power also. I am not quite sure how the ereader from the article works, but the 3 white dots on the right side of the screen made me imagine this, and also I have little to no experience with these electronics so all this is just imaginative and feel free to correct me if you want
There’s enough bezel here to run pogo pins between the sides to charge through from one half to the other (while it’s closed). I honestly thought that’s what the three white dots on the bottom right were to start with. Wiper contacts in the hinges could also work to avoid ribbon cable flex fatigue, but a laptop style cable through the hinge should do fine, especially as it’s open hardware and repairable.
As long as closing the “book” doesn’t make the cable super taut, I would think ot should be OK for a long time, but admittedly I’m not sure. But at least on a DIY device, you know you have access to soare parts, and cables are cheap :)
If you do the cable correctly, and make it only twist in torsion, the cable life will increase 100x or more.
Yeah my first thought as well
Just not a fan of moving parts in handheld devices
Wait can’t we just use nfc on the second screen, no wires and no extra battery connection needed?
Love the idea. Please this be the standard. I am visually impaired and need large font, reading has always been my escape, my education, my dream world
While I am aware of audible, I am a very visual person. Bring on the 2 sided book e-reader!!!
This reminds me of an e-paper version of the Surface Duo. I wonder if the use of a matte screen protector and enabling monochrome-only could replicate some of this magic on a Surface Duo? Of course, battery life would be far less.
For me the killer feature would be folding it open and having one big page.
The tcl 50xl with nxtpaper amoled is probably the best you can get
Basically an LCD that has epaper emulation built in
Plus high dpi
And matte finish not gloss finish
Very good contrast and in normal full color mode they pop out and are vibrant, easy to use the screen in direct sunlight
With basically 12GB of ram (6GB base, 6GB using paging, with flash storage, much faster than hdd) and 2.5ghz arm 64bit octacore, 120hz refresh
You still buy emulation handhelds and shit
I can play the GTA trilogy and a chunk of Nintendo and Sony game library at at least 30fps even at 720p maybe 1080p emulation resolution and using GPU shaders they didn’t have
Nintendo switch? I just need a USB c laptop dock
My smartphone has more processing grunt than a Nintendo switch
Runs basically everything except after Xbox 360 and ps3
“Robert how u get yo home screen to look like a desktop OS?!?!”
Skill issue git güt🤷♂️
I mean with a 7″ LCD it’s a phablet not a phone
Big ass hands I need a big ass phone
With 2k display and 4k support
FHD+
The esp32 may have better battery life
But I Carry a 10 amp hour bank around
I can afford a 20 amp hour solar charger battery bank
Plenty of sunshine