A creator has built a “slabtop” around the Waveshare ESP32-S3-RLCD-4.2 and brought it to life with a homebrewed Solar OS. Text-only, terminal-driven, and programmable with Python and Lua, the project bundles tools like a file manager, web browser, chat client,
There’s a particular kind of excitement that hits when you spot a single component in a catalog or online and can already picture what it could become. For [nilseuropa]. that spark centered on the Waveshare ESP32-S3-RLCD-4.2—an ESP32-S3 paired with a reflective LCD that looks like it belongs in a different era.
The device he wanted wasn’t just functional. It had to feel personal. He paired the Waveshare board with a mini keyboard, then housed everything in a 3D printed case with a battery. The “slabtop” layout was chosen more for building convenience than for any strict love of the form factor. Still, the result lands with the right kind of retro weight: a compact, palm-sized terminal you can actually hold.
Solar OS is the software that makes that hardware more than a display and a few buttons. It isn’t a blank-sheet project. Solar OS is based on FreeRTOS and is built using the ESP-IDE toolset. Right now, applications are compiled into the OS so that everything lives inside a single binary. Persistent storage doesn’t come from that binary, though—it’s handled by the SD card on the Waveshare board.
On the screen, the experience stays strictly text. There’s no graphical desktop to soften the edges; applications launch through shell commands. That might sound limiting. but the project’s pitch is that the device doesn’t lock you out of changing its behavior. Solar OS is user-programmable. with Python and Lua described as “first class citizens.” Both languages can reach into the device through Solar OS APIs to interact with the hardware.
The firmware also ships with a collection of built-in apps. Alongside a serial terminal, it includes an orthodox file manager in the style of Norton Commander, networking tools that cover a web browser and a chat client, plus an MP3 player, an image viewer, a text editor, and games.
In a space where most tinkering stays stuck at demos. projects like this carry a different momentum—because the hardware becomes a platform. Solar OS may be aimed at a niche audience. but it sits inside a broader wave of homebrew operating systems meant to run on custom devices you build with your own hands. For [nilseuropa]. the goal seems simple: take that reflective little LCD. give it a terminal soul. and let the whole machine be something you can keep shaping.
Solar OS Waveshare ESP32-S3-RLCD-4.2 ESP32-S3 FreeRTOS homebrew operating system reflective LCD slabtop terminal Python Lua SD card storage ESP-IDE text terminal
So it’s like a tablet but just text? Kinda cool but why not use an iPad lol
I don’t get it… they “made” an OS but it’s still on an SD card? Sounds like it’s not really independent. Also reflective screens are annoying in bright sun right?
Wait so it has a web browser and chat client but no graphics? That seems fake, like how do you even browse the internet with just shell commands. Maybe I’m missing something but this sounds more like a demo than a real daily thing.
Retro vibes for sure. I saw “Python and Lua” and assumed it’s gonna run any program like Windows or something, but it’s just built-in apps in a single binary? Still though, I bet this will be hacked into a full laptop eventually. Also the 3D printed case with battery… that’s the part I’d worry about swelling or catching fire, not the OS.