E-readers are an awesome creation allowing you to display digital information in a way that requires little battery life. While there’s plenty of very impressive models to chose from on the commercial market, it’s also possible to build one yourself — which is exactly what [kaos-69] did in his Mimisbrunnur project, creating a truly unique e-reader from scratch.
While looking through old junk at home, [kaos-69] came across a case that held a calculator and pen at one point in the distant past. The pen was gone and the calculator no longer functioned but the case held promise. He removed the calculator and got some parts on order. For the e-paper display he went with a 5.83-inch unit that just fit inside the spring-loaded case. The Mimisbrunnur is powered by a 2000 mAh LiPo battery, with a micro SD card reader for storing what will be displayed. The brains come from an RP2040 microcontroller on an Adafruit Feather breakout board, which worked out great as it already takes care of battery management and the 24-pin interface for the e-paper display.
There are also eight buttons that live below the display for user interface, and even some LEDs to aid in reading in the dark. The depth of the case allowed all this to be connected with the use of a perfboard and some risers to set the screen forward, allowing the battery to live behind it. Using the Mimisbrunnur is pretty straightforward with the eight buttons sitting below icons on the screen giving you clear guidance on how to turn the page, add a bookmark, or browse the SD card for another file to open.
We’ve seen some impressive DIY e-readers over the years, such as the dual-screen Diptyx and the Open Book. But this project is an excellent reminder that a device doesn’t have to be complex to get the job done.
Oooh I like that case. I’d imagine airport security might like it more though :-/
People on r/cyberdeck bring some of the most bomb-looking devices through TSA and none of them never really seem to ever be stopped.
So who knows anymore.
I sent a technician on a plane with an open frame switching power supply in the early 1980’s to fix a small office computer at a car dealership with a service contract and poor coverage in that area. Boy, did he get the third degree…
I took a onewheel to new Zealand from San Fran once. Tore the board to bits and carried the battery and attached controller on. Looked about as bombish as it gets. Tsa shrugged and waved me through. They even left a thankyou note in the box of board bits in my checked luggage.
Flew from Venice to London last week. Had to surrender a pen with a tapered end (not even the writing bit) because it was ‘too pointy’. I asked how pointy was tooo pointy? They responded ‘that pointy’. Touche airport security.
The thought had crossed my mind :-) At least it doesn’t have a 7-segment display, see https://www.loweringthebar.net/2015/09/texas-police-wont-charge-for-clock.html
I used to save cases like that with the intention to put devices like this into them. Finally acknowledged years ago they were taking up more space than they were worth, and I would never in my remaining time use them. So with a bit of regret I binned the lot. Doesn’t diminish the good work done here though. Kudos.
I am a bit worried about the corner of that display though, hanging out in harm’s way like that.
“I am a bit worried about the corner of that display though, hanging out in harm’s way like that.”
Yes, When cutting the base plate I made the mistake of rounding the corners too roughly match the shape of the case, only to find later that I needed to place the display at the very edge. If I revisit the mechanical side of the project, which I might, I will rectify that mistake. How does the old proverb go, “do as I say, don’t do as I do” :-)