Velxio is a self-hosted, open-source simulator for Arduino, ESP32, and Raspberry Pi boards that operates directly in a web browser. It allows users to drag and drop boards, connect components, write and run Arduino or Python code, and access the serial console without needing hardware.
Velxio is inspired by the Wokwi simulator, incorporating AVR8 and RP2040 emulators and a QEMU fork for ESP32 Xtensa emulation. The primary difference is Velxio’s ability to be self-hosted, although there is an online demo available.
Velxio currently supports 19 targets across five architectures with 48 components. Unique features include support for multiple heterogeneous boards in the same circuit and full QEMU emulation for ESP32 and Raspberry Pi 3.
Installing Velxio on an Ubuntu 24.04 machine can be done with a single Docker command. Once installed, it can be accessed in a web browser at http://localhost:3080.
After trying the simulator, it was easy to add components and boards and create circuits. However, some issues remain, such as accessing the Raspberry Pi 3’s serial console. Some ESP32 samples failed to build, though simpler examples like the Blink LED worked.
More details and the code can be found on GitHub. Velxio is available under a dual-licensing model: an AGPLv3 license for non-commercial use and a commercial license for proprietary use.