Instant MCU dev
Velxio published an open‑source browser emulator that runs 19 microcontrollers (Arduino Uno, ESP32 among them), letting you write and debug embedded code without physical hardware. (x.com) That removes a major onboarding bottleneck and can accelerate CI feedback loops for embedded teams and hobbyists. (x.com)
David Montero Crespo published a technical post about Velxio on March 28, 2026 laying out its design choices and implementation timeline. (dev.to) The system mixes client‑side emulation (avr8js and rp2040js), a hand‑written TypeScript RISC‑V core for chips like the ESP32‑C3, and a QEMU backend to handle Xtensa and Raspberry Pi 3 binaries. (dev.to) On the AVR path the emulator runs cycle‑accurate at 16 MHz with an execution loop tuned to roughly 60 frames per second, using a per‑frame cycle target of about 267,000 cycles. (dev.to) Velxio’s UI bundles the Monaco code editor, a component canvas and wire system, a serial monitor, and uses arduino‑cli on a FastAPI + Python backend to compile sketches. (dev.to) The GitHub repository includes a standalone Dockerfile and docker‑compose manifests for self‑hosting, and recent commits added an AGPLv3 license plus a commercial license file. (github.com) Repo metadata shows active development with roughly 300 commits, about 428 stars and 22 forks as of late March 2026, and a Velxio 2.0 announcement drew substantial discussion on Hacker News (≈160 points). (github.com) Documentation and project pages list over 48 interactive electronic components exposed in the simulator, and the author explicitly notes universities and bootcamps as target deployers for the self‑hostable instance. (github.com)
