An open-source ESP32-S3 e-paper development kit. Offers hardware access to 24-pin e-paper communication over SPI, 4-bit SDMMC, USB-C, button array, and optional modules for series LED driver and battery overcharge/discharge protection.
The heart of de-link. Designed to work with any GoodDisplay 24-pin SPI e-paper display.
Specifications:
- MCU: ESP32-S3 (240 MHz dual-core, 512 KB SRAM, PSRAM (buy whichever you want), 16MB Flash)
- Display Interface: 24-pin SPI e-paper (supports 3.97", 4.26", 7.5", and more)
- Storage: 4-bit SDMMC microSD interface
- Power: LiPo battery with overcharge/discharge protection (bring your own battery)
- Connectivity: Wi-Fi 802.11b/g/n, Bluetooth LE, USB-C with OTG
- Input: Dual 4-switch resistor ladders, multi-function GPIO, reset button
- Optional Modules: Series LED driver for frontlight (cool/warm control), battery protection circuit for salvaged single-cell lithium batteries
This is my first working prototype built around a 4.26" GoodDisplay panel in a 3D-printed enclosure. It's functional and something I use every day, but it's just the starting point. The design is open so you can build your own with any compatible display size. For more info on that, check out things I've been trying.
Initial prototype: 4.26" display with 3D-printed case
The enclosure is fully customizable and 3D-printable. Most PCB components are hand-solderable (0805/SOT-23). When something fails, you replace it. The screen is removable. You can reprint the case as many times as you need.
My current prototypes (mine and my gf's)
Out and about
Optional frontlight module with cool/warm tuning. **THIS IS THE FIRST UNIT I BUILT, THE ONES ABOVE ARE NEWER.**
My Kindle's frontlight broke. I wanted an e-reader I could actually control and repair. So I designed a PCB, built a case, and got it working. Now I'm sharing it because I believe open hardware leads to better hardware.
See Philosophy for the full story.
This project needs community support to grow. Without contributors, testers, and feedback, this remains a single prototype on my desk. The roadmap, timeline, and future direction all depend on community engagement. If you're interested in e-paper, open hardware, or just building cool things, join in.
- PCB Design - See the KiCad files at my repo here, I will provide 1.0 production files later. See Roadmap below.
- Firmware - Check out my fork of crosspoint-reader for e-reader software built on de-link, as well as the "sdk" that has display code for the 4.26" display as well as the buttons/sd card here
- 3D Enclosures - Coming soon, access first by supporting
See cost breakdown for the rough BOM and a full picture of how much a unit should cost. TLDR: About $60ish before shipping, maybe a bit more if you pay for PCBA. But I implore you to try and build it yourself. All components are hand-solderable for most with basic soldering materials, save for the pesky ribbon cables which interface to the display.
It will depend on the software and the battery that's used. Both are up to you. However if using with crosspoint-reader and reading for ~30 minutes a day with a 650mAh battery, it should last for weeks. I don't really know. See my current-draw measurements here.
- Cost - Price breakdown of component + unit cost.
- Philosophy - Design principles and why this project exists
- Comparison - How de-link compares to XTEink and M5Paper
- Roadmap - Development phases and upcoming releases
- Prototyping - See what I've played around with so far.
Community:
