A tiny touchscreen dashboard boots up, updates its readings and responds to taps, all inside a web page.

esp32sim, by Joakim Eriksson and contributors, emulates ESP32 hardware in Rust and runs firmware in the browser through WebAssembly. The public demos include an energy dashboard and several small devices you can explore without wiring a board.

Eriksson describes building it with Claude's help reading specifications and implementing parts of the emulator, alongside his own experience developing emulators. The result still needs that engineering judgment: supported chips and peripherals have different levels of completeness.

Try the touchscreen dashboard:
mikroverk.github.io/esp32sim/run.html?wasm&fw=panel

Other demos and source:
mikroverk.github.io/esp32sim/