Simulator

Playground

Pick an example sketch. The server builds it with arduino-cli and the ATmega328P in your browser (avr8js) runs the real .hex, with virtual sensors attached so real values flow.

FreeNo loginRuns in browser

digital_tone_melody.ino

Play a melody on a buzzer

Read only

Pitches and lengths live in arrays and are played in order.

Try thisChange a 4 in noteDurations to 8 — that note becomes half as long.

What the parser saw

extracted from #include · #define · pinMode

L0 simulator

avr8js · ATmega328P

Pin states

dark border = declared in the sketch · copper = HIGH · dashed = pull-up input

Serial monitor (9600 bps)

Virtual sensor defaults: DS18B20 25.1 °C · DHT22 24.5 °C/55 % · HC-SR04 42 cm · BME280 25.08 °C/1006.5 hPa · potentiometer 2.5 V — change them with the sliders above. What you see is what the simulator observed; this page passes no verification gate.

The same sketch, as far as verification

Leave the code as it is. Take it into a project and the server checks the sketch against the simulation, then reports the circuits it is missing and why each one is needed.

Logic — the server replays the simulation you just watched and checks it against the sketch
Electrical — catalogue grounding, golden patterns, ERC, the pin contract. Every circuit we add says why
Board files — KiCad, Gerber, BOM. Not open yet

Start a project from this sketch Example details