Simulator

Arduino simulator, running in this tab

Mokxi is a free Arduino simulator that runs in your browser, with nothing to install and no account needed. Wire a circuit, write the sketch, press Run. Mokxi models a complete Arduino Uno R3, down to the ATmega328P, and the firmware runs on our own AVR core rather than being interpreted or faked.

192parts on the bench
25boards running now
1.00xreal time, on every board

Arduino Uno: 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 core

Every ATmega328P mnemonic, at 16 MHz, with the datasheet cycle count for each one.

Timers and I/O

Three timers in every waveform mode including hardware PWM, USART0, the ADC, external and pin-change interrupts, sleep and EEPROM.

Wiring

The Uno stands beside the breadboard and reaches it with jumper wires, because its headers are two inches apart and will not push into one, on the real board or on this one.

Go further

The full board page

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

Arduino Uno simulatorBlink, a button and the serial monitor, running.

Questions

Which Arduino does this simulate?

The Arduino Uno R3.

Does my sketch run unchanged?

The model uses the ATmega328P register map for its supported peripherals. Test your finished sketch on the physical board before relying on it.

Is it free?

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

What is not modeled?

Shields as physical parts, and the Arduino IDE library ecosystem. Wire the same circuit on the breadboard and the runtime here is Arduino-shaped rather than the Arduino core itself.

Try your own firmware on the Arduino

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

Start building Open the editor