Design, code, and simulate Arduino circuits — on your desktop or in the browser.

Place components on a breadboard, wire them up, write a sketch, press Run, and watch the LEDs actually light. The simulator runs a real ATmega328P emulation against an analog solver, so leave out an LED's resistor and you see it being over-driven instead of the mistake being silently ignored.

Works fully offline on desktop. No account required.

Try it in your browser →  ·  What it is  ·  Download for desktop

Why this one

There are other Arduino simulators. This one is different in three ways:

• A real analog solver. Component values matter. Voltage dividers divide, and an under-sized current-limiting resistor over-drives the LED instead of being silently ignored.
• Native desktop, fully offline. No browser, no account, no connection — which matters in locked-down school labs and on unreliable networks.
• Open source, open format. Circuits are plain-text .cdl files you can read, diff, and version. Nothing is locked in a vendor's database.

Features

• Circuit canvas — drag components onto a breadboard, wire them with multi-point orthogonal routing, rotate, flip, and edit properties. Parts snap to a real 0.1" hole pitch, so legs land in holes the way they do in life.
• Code editor — Arduino-style editor with syntax highlighting, autocomplete, multiple tabs, and an integrated serial terminal.
• Real-time simulation — ATmega328P emulation at 16 MHz plus an analog solver, running in a background isolate so the UI stays responsive.
• Serial plotter — graph values streamed over Serial.println().
• Undo/redo, copy/paste, autosave, and full keyboard control of the canvas.
• Cross-platform — macOS, Windows, Linux, and the web.
• Multi-window on desktop.

Components

Arduino Uno · half and full breadboards · LED · resistor · capacitor · potentiometer · push button · piezo buzzer · KY-037 microphone · SG90 servo

Every part is drawn at its real physical size — an Uno is 68.6 × 53.4 mm on the canvas, and test/features/canvas/real_world_dimensions_test.dart keeps it that way.

Bundled examples

blink · breadboard · clap_rhythm · mic · piezo_buzzer · servo

Quick start

# Prerequisites: Flutter 3.47.5 (pinned in .fvmrc; `fvm use` picks it up)
git clone --recursive https://github.com/PinBench/pinbench.git   # the .cdl/.pdl packages are submodules
cd pinbench
flutter pub get
dart run build_runner build --delete-conflicting-outputs
flutter run

The bundled examples ship precompiled, so they run immediately. To compile your own sketches on desktop you also need arduino-cli:

arduino-cli core install arduino:avr
# For sketches that drive the OLED display (`Adafruit GFX Library` and
# `Adafruit BusIO` come with it as dependencies):
arduino-cli lib install "Adafruit SSD1306"

Generated *.g.dart files are gitignored. Run build_runner after every clone, pull, or branch switch, or the build will fail with missing symbols.

Platform notes

Platform	Requirements	Build
macOS	Xcode 16+	flutter build macos
Windows	Visual Studio 2022+, Windows SDK	flutter build windows
Linux	clang, cmake, ninja, pkg-config, GTK 3 dev libs	flutter build linux
Web	—	flutter build web --wasm

The browser cannot run arduino-cli, so the web build compiles edited sketches through a small remote service. Without one it still runs the bundled examples. See PinBench/compile-service to run your own.

Development

# Tests. The 'arduino' tag marks tests needing a local arduino-cli toolchain.
flutter test --exclude-tags arduino

# Formatting — CI enforces this at the project's page_width of 100
dart format lib test

# Web preview with local compilation: start PinBench/compile-service on :8080
# (see its README), then
flutter run -d chrome --dart-define=COMPILE_API_URL=http://localhost:8080

Building from source

A build from this repository is the full local app: the canvas, the simulator, the code editor and every component, with no account needed. Accounts, cloud projects, sharing and the circuit assistant belong to PinBench's hosted builds and are absent from a build from source.

The one service you may want alongside it is the compile service — PinBench/compile-service, a small Node service wrapping arduino-cli, with a Dockerfile and a hardening guide — which lets the web build compile edited sketches.

File formats

A circuit is saved as .cdl and a part is described in .pdl. Both are specified, with pure-Dart readers any tool can use, in their own repositories: PinBench/cdl and PinBench/pdl.

Contributing

Contributions are welcome — components, board definitions and bug fixes especially. (The interface is English-only for now; it has no translation support yet.)

Please read CONTRIBUTING.md first. Note that we ask contributors to sign a CLA; it takes one click, you keep your copyright, and documentation and typo fixes are exempt.

Security issues should not go in a public issue — see SECURITY.md.

Licence

• The app is Apache-2.0 — see LICENSE.
• The compile service is AGPL-3.0 — see PinBench/compile-service. A commercial licence is available if you need to run a modified copy as a closed service.

Apache-2.0 covers the code, not the name. See TRADEMARKS.md — forking is welcome and always will be, just under your own name.

Tech stack

Area	Technology
Framework	Flutter 3.47+ / Dart 3.13+
State	Riverpod 3.x with codegen
Canvas	Custom CustomPainter
Editor	re_editor
AVR emulation	avr8_dart (native, and WebAssembly on the web)
Analog solver	ngspice_dart — a pure-Dart port, no FFI or native libngspice
Audio	flutter_soloud (native), Web Audio (web)
Multi-window	multiview_desktop

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"Arduino" is a trademark of Arduino SA. This project is independent and is not affiliated with, endorsed by, or sponsored by Arduino SA. "Flutter" and "Dart" are trademarks of Google LLC.