There’s no shortage of eReaders featuring E Ink displays. But the Diptyx eReader stands out in a few ways: it has two E Ink displays and a hinge in the middle that lets you open and close the device like a book. And it’s designed as an open source project: the firmware and hardware designs will both be available for users to inspect and modify.
Developer Martijn den Hoed has been working on the design for a while, and now there’s a Crowd Supply crowdfunding campaign for the dual-screen, open source eReader. Backers can reserve one for a pledge of $230 + $12 for shipping, the Diptyx eReader is expected to begin shipping in May, 2026.
The Diptyx is about the size of a paperback book, measuring 120 x 150 x 14mm (4.7″ x 5.9″ x 0.6″) when closed, or 226mm wide (8.9″) when opened. It weighs 300 grams, or about 10.5 ounces.
Its two screens are 5.83 inch, 640 x 480 pixel black and white E Ink displays, which are… cheap, I guess. Those screens should each have about 137 pixels per inch, which is a lot lower than the 300 ppi you’d get from even an entry-level Kindle. But given that this is a custom design made by a hobbyist using off-the-shelf components, these screens should help keep the Diptyx affordable… although den Hoed hasn’t announced how much the device will cost or when it will be available yet. You can sign up at Crowd Supply to be notified when the campaign goes live.
Other features include a 240 MHz ESP32-S3-N16R8 microcontroller, a 2GB user-replaceable microSD card for storage, dual 1500 mAh batteries, and a USB-C port for charging and data.
The firmware is designed for reading DRM-free EPUB files and not much else. But the software will be released under an MIT license, so users can modify it to add features.
While the device has the hardware to support WiFi 4 and Bluetooth 5.0, wireless capabilities aren’t enabled in the stock firmware. But since this is an open source device that’s meant to be hacker-friendly, there’s nothing stopping users from modifying the firmware to add support for wireless features to access the internet, local networks, or add support for Bluetooth headphones, keyboards, and other devices.
via NotebookCheck and /r/ereader
This article was first published October 24, 2025 and most recently updated December 12, 2025 to indicate the start of the crowdfunding campaign.
esp have vulnerability
meybe in future using raspbery pi 2350 or stm
Better design coice than foldable display
It’s a cool concept, and I’m not opposed to it in theory.
In practice, I can’t imagine reading on such a low res display. My old LCD-screen Ectaco Jetbook Lite had a higher ppi.
If this thing is running on ESP32 hardware, why not use a pair of M5Stack Paper devices? Those have a much higher pixel count than these WaveShare screens (I’m guessing that’s what they are, anyway).
close book and flip the pages
I have fond memories of the old Microsoft Courier concept. Now that we have the technology to make it (both hardware and software), it’s a little disheartening that nobody is giving it a proper shot.
I think that is really neat. it seems like a good way to read a book, opening it like one would a book and closing it to protect the screens.
It’s dumb. Skeuomorphic designs had their time in UX cause that cost nothing. IRL, nobody is paying for such a gimmick.