Arduino Micro simulator, the Leonardo in a breadboard
The Micro is the Leonardo’s ATmega32U4 on a board 48 by 18 mm that pushes into a breadboard. The same chip, the same pin numbers and the same programs; Serial is the chip’s own USB and Serial1 is pins 0 and 1.
- 6peripheral areas modeled
- 1project ready to run
- Real timeon your own machine
What is modeled
Taken from the board's own contract document and put in plain words, with what is missing beside it.
Modeled
- Core
- The ATmega32U4 at 16 MHz, every instruction with its datasheet cycle count
- Timers
- Four, including the ten-bit timer 4, with PWM on seven pins
- USB serial
- Serial as a byte pipe to the monitor; Serial1 as the real USART on pins 0 and 1
- ADC
- Twelve inputs, six of them also digital pins
- Lamps
- L on pin 13, and RX and TX on PB0 and PD5, lit when their pins go low
- The board
- Two rows of seventeen, 0.6 inch apart, with MISO, SCK, MOSI and SS on holes of their own
Not modeled
- The USB stack: no enumeration, and no keyboard or mouse.
- Everything the Leonardo model leaves out.
Open one and press Run
Each of these opens in the editor exactly as it is drawn here.
Every built-in project on the Micro
Each has its own page with the circuit running, the code and a parts list.
Arduino libraries that compile as they are
Paste a tutorial that includes one of these and it builds. For any other library, the build names the Mokxi header that does the same job.
And 17 more, 25 in all: OneWire.h and DallasTemperature.h; Adafruit_BME280.h, Adafruit_BMP280.h and SparkFunBME280.h; RTClib.h; Adafruit_SHT31.h; Adafruit_PCF8591.h; Adafruit_ADXL345_U.h; LedControl.h; Adafruit_LEDBackpack.h; Adafruit_TCS34725.h; Adafruit_SGP30.h; Adafruit_INA219.h; Adafruit_ADS1X15.h; Adafruit_MCP23X17.h; Bounce2.h; Keyboard.h and Mouse.h; Joystick.h; HX711.h.
Questions
Is it free?
Yes. Every board and every part is on the free plan, with no account needed.
Will a Leonardo sketch run on it?
Yes, unchanged. It is the same chip with the same pin numbers, and it runs the same programs.
Where are SDA and SCL?
On pins 2 and 3, as on the Leonardo, not on A4 and A5 as on an Uno: on this chip I2C is on port D.
Why does driving SS low light a lamp?
Because SS is PB0, and the RX lamp hangs from 5 V on PB0. RXLED1 and RXLED0 are the names for it.
The other boards
Every one of these runs today, and every one is free.
Every Arduino board in one place: the Arduino simulator.
A RISC-V chip at 160 MHz, on the real memory map.
The classic Arduino, with an ATmega328P running at 16 MHz.
The Uno’s chip on a small board that fits a breadboard.
The big Arduino, with 54 digital pins and four serial ports.
An Uno-shaped board whose chip does its own USB serial.
A second RISC-V board, with 31 pins and simulated WiFi.
The classic ESP32 at 240 MHz, with simulated WiFi.
The ESP32-S3 at 240 MHz, with USB serial and an RGB LED.
Try it on your own firmware
What you build here runs on the board on your desk, unchanged. Nothing to install and no account needed.