New: the Raspberry Pi Pico W

Design, code and simulate Arduino circuits.

Wire a breadboard, write the sketch, press Run, and watch real current move through every wire.

Open the playground Download
The PinBench canvas showing the clap-rhythm example: an Arduino Uno wired across a breadboard to three LEDs, three push buttons, a piezo buzzer and a microphone module. The code editor with the blink sketch open, and the serial monitor panel below it.

Runs where you work. One circuit file, everywhere.

Circuits are plain-text .cdl files you can read, diff and commit. The same file opens in a browser tab and on the desktop.

Download View the source
  • WebAny modern browser
  • macOSDesktop app
  • WindowsDesktop app
  • LinuxDesktop app

Write the sketch , wire the board , and watch the current .

Start from a working circuit. Each one opens wired up, with no sign-in.

Browse every example, with filters

What is inside. The circuit, the code and the run, in one window.

Simulation

You can see the current
Dots travel each wire in the direction current flows. Speed, size and brightness carry its magnitude, from 1 µA to 100 mA.
A real analog solver
Voltage dividers divide. Leave out the current-limiting resistor and PinBench flags the over-driven LED instead of ignoring it.
Real firmware, not a mock
An ATmega328P emulation at 16 MHz runs the sketch you wrote, with timers, interrupts and Serial.
Parts at true size
An Uno is 68.6 × 53.4 mm on the canvas, and holes sit on a real 0.1″ pitch, so legs land where they would in life.

Editor

Circuit canvas
Drag parts onto a breadboard and wire them with orthogonal routing. Rotate, flip and edit properties; parts snap to the holes.
Code editor
Arduino-style editing with syntax highlighting, autocomplete and tabs, plus an integrated terminal on desktop.
Serial monitor and plotter
Read Serial.println() as text, or graph the values as they stream.
Undo, redo, autosave
Copy and paste, full keyboard control of the canvas, and work that saves itself as you go.

Browser or desktop

In the browser

  • Open an example and design the circuit
  • Read and edit the sketch
  • Run the real simulation
  • Serial monitor and plotter

Desktop only

  • Open a local folder and save to disk
  • Compile your own sketches offline
  • Embedded terminal
  • Work that persists across reloads

A browser cannot run arduino-cli, so edited sketches compile through a small hosted service. The desktop app compiles locally, with no connection at all.

Describe it, and let it wire it up.

The assistant turns a plain-English request into a real circuit and the sketch to drive it. Then you check its work on the canvas.

  1. It runs on your machine, not ours

    Point it at Ollama, LM Studio or llama.cpp. Nothing leaves your computer, there is no account, and it works with the network off.

  2. Or bring your own key

    Use any OpenAI-compatible endpoint. There are no credits and no per-prompt cost, because we are not in the middle of it.

  3. Circuit and code together

    It writes the .cdl and the .ino as one answer and lays the parts out, so the wiring and the firmware agree.

  4. Then check it by running it

    An assistant can be wrong about wiring, and this one says so. Press Run and find out, against the real emulator and solver.

The parts bin. Real pinouts, drawn at true size.

Basics and power

Output

Boards

Sensors and input

Pins, settings and simulation notes for every part

Open source, and buildable.

Apache-2.0. Paying is how the project gets funded, not how you get access: there is no licence check, and nothing is withheld from the build you make yourself.

View the source See pricing

Open it and wire something up.

It loads in a browser tab. Nothing to install, nothing to sign up for.

Open the playground