Reflective LCD Slabtop Terminal Runs Homebrewed Solar OS

June 26, 2026 by Tyler August 18 Comments

Have you ever spotted something in a catalog or on a website and just known you had to build a project around that one part? That’s how [nilseuropa] felt about the Waveshare ESP32-S3-RLCD-4.2, which — as you might guess from the name — pairs an ESP32-S3 with a reflective LCD. With a screen reminiscent of a palmtop of yore, [nilseuropa] wanted a personal device, and needed something to run on it. That’s where Solar OS comes in.

Physically he’s paired the Waveshare board with a mini keyboard and put them together in a handsome 3D printed case with a battery. The slabtop form-factor was more for ease-of-creation than any preference; in the project’s reddit thread [nils] is reaching out for help making something cooler, possibly of the palmtop form-factor. He also describes some of the thinking behind his operating system.

He’s not starting entirely from scratch: it’s based on FreeRTOS and the ESP-IDE toolset. Right now all applications are built with the OS into a single binary, while the SD card on the Waveshare board handles persistent storage. The interface is pure text, with all applications launched via shell commands. That doesn’t mean you have to go back to your PC to add anything, however.

The system is user-programmable, with Python and Lua scripting as “first class citizens”, having access to the hardware through the Solar OS APIs. As for the applications built into the firmware, it looks like along with the serial terminal, you get quite a lot: an orthodox file manager à la Norton Commander, networking tools that include a web browser and chat client, MP3 player, image viewer, text editor, games, and more.

While they are obviously pretty niche projects, we do appreciate that there’s a growing collection of homebrew operating systems that you can run on your bespoke computing device.

Ebike Display Uses Reflective LCD

May 31, 2026 by Bryan Cockfield 19 Comments

Although LCD displays have been used in almost every type of consumer electronics display over the last two decades, many of these screens have a few downsides that limit their usefulness in certain situations. As any owner of an early digital watch, an early laptop, or an early digital camera will testify, these displays often completely fail in direct sunlight. And, a currently new technology often using inexpensive displays in full sunlight conditions is ebikes, so [Volos Projects] decided to use a unique LCD display to solve this issue.

The display is called a reflective LCD (RLCD) and is actually a fairly old but overlooked piece of technology. Displays like these have a reflective layer that bounces ambient light back to the user, increasing contrast and readability in high light, especially when compared to more common transmissive displays. This build is based on a board from Waveshare, which includes the screen and its driver components, and [Volos Projects] integrated this into a test stand that mimics an ebike’s speed sensor and other hardware like turn signals. The display shows the bike’s speed and a few other indicators, and thanks to the screen, this information can be easily seen in full sun.

Although he doesn’t have it on an actual e-bike yet, he hopes it will be useful for those who want to try out something like this with their substandard e-bike displays. The code he’s used is available on a GitHub page for anyone interested. We’d imagine that a low-cost display like this would pair well with an open-source ebike like this one.

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