May 18, 2026
Math class, but make it messy
Graphing Scientific Calculator Based on the ESP32
Open-source calculator dreams big, but commenters are roasting the broken buttons
TLDR: NumOS is an ambitious open calculator system for a small, cheap chip, aiming to rival famous school calculators with graphing and advanced math features. Commenters loved the idea but piled on over broken links, missing hardware details, and a flashy website that made the project feel more style than substance.
A tiny homemade calculator project just walked into the internet wearing a very big crown. NumOS wants to be an open, community-owned graphing calculator that can take on the big classroom names, with paper-style math display, graphing, equation solving, and even wild extras like a bridge simulator and a digital sand-box game. On paper, it sounds like the nerd fantasy device: cheap hardware, open software, and no giant company in charge.
But the real show was in the comments, where people immediately turned into unpaid quality-control inspectors. The loudest reaction was basically: cool dream, but why are the links broken? One commenter went straight for the jugular, calling the site’s “100% open” message misleading when key pages like the schematic and manifesto weren’t working. Another was baffled that the first thing they spotted was a glossy “marketing website” for a calculator, joking that a “neo-vibey” launch page with dead buttons was exactly the wrong energy for a hacker project.
Then came the smaller but very relatable gripes: giant 3–5 MB photos for people on limited data, and a plea asking whether this could run on another handheld device instead. So the mood was a perfect internet cocktail: part hype, part suspicion, part roast session. People like the idea of an open calculator challenger, but the community verdict right now is brutal and funny: before it can replace your school calculator, it may need to survive its own homepage.
Key Points
- •NumOS is an open-source scientific and graphing calculator OS for the ESP32-S3 N16R8 with 16 MB flash and 8 MB PSRAM.
- •The project is in a major refactor, migrating its core symbolic math engine to Giac and adding STIX Two Math for improved formula rendering.
- •Its feature set includes a Giac-backed CAS, natural math display, graphing, equation solving, calculus tools, persistent variables, and PC control through SerialBridge.
- •NumOS uses LVGL 9.x for its interface and a modular application architecture coordinated by SystemApp.
- •The platform also includes advanced apps such as Bridge Designer with Verlet-based physics and Particle Lab with 30+ materials, reactions, and LittleFS save/load support.