Simulator

Raspberry Pi Pico W simulator, running in this tab

Mokxi is a free Raspberry Pi Pico W simulator that runs in your browser, with nothing to install and no account needed. The Pico W is a Raspberry Pi Pico with a wireless chip beside it. Mokxi runs the RP2040 exactly as it runs a Pico, does not model that chip at all, and simulates the WiFi instead, saying so on every page that mentions it. Wire the circuit, write the sketch, press Run.

  • 505parts on the bench
  • 45boards running now
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Raspberry Pi Pico W: blinklive0.000 s 0.00x
Click to open it in the editor
Real firmware, running right now on our own core. Click it to open the circuit in the editor.
What is modeled

The numbers, not the marketing

Taken from the board's own contract document and put in plain words.

The same chipAn RP2040 on our own Cortex-M0+ core at 125 MHz, with SIO GPIO, the microsecond timer, UART0 and eight PWM slices. A program built for a Pico runs here unchanged.
WiFi, simulated, and it says soThe board joins a network, fetches a page and serves one, with the Arduino calls a tutorial gives you. For a sketch the CYW43439 is not modeled, and there is no 802.11 under it; MicroPython and CircuitPython drive the modeled chip on its pins, on the same simulated network. Four made-up addresses under .mokxi answer inside this tab, and signed in you can switch on real internet for HTTP and HTTPS requests to real hosts. Bluetooth is not simulated at all, and a sketch that reaches for it will not compile.
The LED is not on GP25A Pico W’s lamp hangs off the wireless chip, and digitalWrite(LED_BUILTIN, HIGH) gets there: the runtime sends it down the same path the Arduino core uses on the real board. Writing 25 lights nothing here, and nothing on a real Pico W.
Go further

The full board page

Every peripheral area, every example and the wiring notes, in one place.

Raspberry Pi Pico W simulatorBlink, a button and the serial monitor, running.
Guides

Step-by-step guides for the Pico W

Each one has the parts, the wiring and the code, and ends in a circuit you can run.

How it works

Three steps from a blank tab to a running circuit.

  1. Open the editor

    It runs in your browser tab. Nothing to install, and you need no account to start.

    Your first project
  2. Wire it and write the code

    Drag parts onto a breadboard, run each wire from pin to pin, and write the sketch beside it.

    Wiring
  3. Press Run

    Your sketch compiles in the tab and runs on a model of the chip, with the Serial Monitor beside it.

    Run and serial
Reviews

What makers say about Mokxi.

“The AI checker helps check and correct my circuits, and it has way more components than Tinkercad. As a student I really appreciate the tool.”

ChloeEngineering student

“I’d been looking for a real online electronic simulator that was intuitive and complete when I found Mokxi. I was able to quickly import a Fritzing file and my Arduino sketch and start testing. Mokxi has all of the makings for the best online Arduino simulator I have been able to find!”

JayModel builderFeatured in his DioramaOS post

“I’m using Mokxi to develop and simulate an STM32-based four-wheel-drive robot car before building the actual hardware. It allows me to experiment with DC motor control, PWM, RPM measurement using photointerrupters, and different acceleration, braking, and reversing strategies, helping me understand and refine the system before implementing it in real life.”

NusretRobot car builder, Hamburg

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FAQ

Questions, answered.

Is it free?

Yes, all of it, with no card and no account needed to try it.

Can it connect to WiFi?

To a simulated one, yes, and it says so. Your sketch uses the real Arduino calls and the board joins, fetches and serves; so do network.WLAN in MicroPython and wifi.radio in CircuitPython. There is no radio under it, though signed in you can switch on real internet. If real wireless is the point of your project, this is not the tool for it.

Why will digitalWrite(25, HIGH) not light anything?

Because on a Pico W GP25 is not the LED: it is the chip select for the CYW43439. The LED is on that chip’s own GPIO 0, and LED_BUILTIN goes there. A real Pico W behaves the same way.

Is it different from the Pico simulator?

Only in those respects: the LED is on the wireless chip rather than GP25, and there is a simulated network the Pico does not have. Same core, same pins, same compiler. The images are not interchangeable, because a Pico W one writes to a block a Pico leaves unmapped. Pick this one when it is the board on your desk.

Simulators for one kind of circuit

A servo, a display, a motor driver or a rectifier, each already running.

Try your own firmware on the Pico W

What you build here runs on the board on your desk, unchanged. Nothing to install and no account needed.