Arduino Leonardo ATmega32U4 Official Development Board

The Arduino Leonardo R3 Official Development Board brings native USB connectivity to the classic Arduino form factor, removing the need for a separate USB-to-serial converter found on boards like the Uno. Built around the ATmega32U4 running at 5V and 16MHz, the Leonardo can present itself to a connected computer as a keyboard, mouse, joystick, or MIDI device while still behaving like a standard Arduino for sketch uploads and serial communication. This built-in USB capability opens up projects that older Arduino boards can't handle on their own, such as custom macro pads, game controllers, and HID peripherals. If you're after the same USB HID features in a smaller footprint, our Arduino Pro Micro 5V uses the same ATmega32U4 chip. Looking for a lower-cost option with the same functionality? Our Arduino Leonardo Compatible Development Board is worth a look. Key Specifications Microcontroller: ATmega32U4 Operating Voltage: 5V Clock Speed: 16MHz Recommended Input Voltage: 7V to 12V Input Voltage Limits: 6V to 20V USB Interface: Micro USB with native USB support Digital I/O Pins: 20 PWM Outputs: 7 Analog Inputs: 12 Flash Memory: 32KB (4KB used by bootloader) SRAM: 2.5KB EEPROM: 1KB DC Current per I/O Pin: 40mA 3.3V Pin Current: 50mA Board Dimensions: 68.6mm x 53.3mm Features Native USB connectivity eliminates the need for a separate USB-to-serial converter Fully compatible with the Arduino IDE for straightforward programming Can act as a USB keyboard, mouse, joystick, MIDI controller, or other HID device 20 digital I/O pins for sensors, displays, motors, and other peripherals Seven PWM outputs suited to LED dimming, motor control, and servos Twelve analog inputs for precise sensor readings DC barrel jack, Micro USB connector, ICSP header, and reset button included Onboard bootloader allows sketches to be uploaded directly over USB Applications USB keyboards and macro pads Gaming controllers and custom HID devices Robotics and automation IoT and smart home projects Sensor data acquisition STEM education and prototyping MIDI controllers and interactive installations Programming Notes Select "Arduino Leonardo" from the Tools > Board menu in the Arduino IDE before uploading a sketch. The onboard bootloader handles uploads directly over Micro USB without an external programmer. The board can also be programmed through the ICSP header if you prefer to bypass the bootloader entirely. Because the Leonardo resets itself in software when the IDE opens its virtual serial port at 1200 baud, uploads generally happen without needing to press the physical reset button. If an upload doesn't start automatically, pressing reset on the board will kick the bootloader into its roughly 8 second upload window. Resources Arduino Leonardo Schematic (PDF) ATmega32U4 Datasheet You can also browse our complete Arduino collection to find the right board for your next project. New to Arduino? Our What is Arduino guide explains the basics of the platform before you dive in. From there, follow our Arduino Getting Started Guide to learn the basics, then build your first project using our LED Blink Tutorial.