Velxio – Arduino emulator running entirely in the browser

Summary: Velxio is an open-source browser-based Arduino emulator that lets users write sketches, compile them with arduino-cli, and simulate circuits using a real AVR8 CPU emulator and interactive components. It supports multiple boards including Arduino Uno, Nano, Mega, and Raspberry Pi Pico with peripherals mapped to visual elements.

What it does

Velxio compiles Arduino code and simulates microcontroller behavior and peripherals like GPIO, SPI, I2C, UART, and ADC within the browser using AVR8 and RP2040 emulation.

Who it's for

It is designed for developers, embedded engineers, and makers experimenting with Arduino circuits without hardware.

Why it matters

It enables circuit development and testing entirely online without installing software or hardware.