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Getting Started

A miniature version of the Audrino Leonardo, the Arduino Micro has 20 digital input/output pins, 12 analog input/output pins and a ATmega32U4 microcontroller. It is powered by a micro-USB port or 7-9 volt direct input through the VIN pin.

Arduino Micro Pinout

Power Pins

  • VIN pin: 7-9 volt direct input pin used to power up the Arduino board
  • 5V pin: regulated 5v output for the externally connected components.
  • 3V3 pin: regulated 3.3v output for the externally connected components.
  • GND pins:  ground pins for externally connected components
  • RST: Reset pins,  Low/0 volt resets the board
What are digital pins?

The Arduino Micro has 20 digital input/output pins. These pins operate at 5 volts. Reading in binary (High or Low), digital pins read whether an electric signal is present or absent. 

What are Analog Pins?

The Arduino Micro has 12 digital input/output pins. These pins are also digital input/output pins. However, analog pins map input voltages between 0 and the operating voltage (5V or 3.3V) to integers between 0 and 1023.

What is PWM?

Pulse Width Modulation(PWM), is a technique for getting analog results varying the width of the pulses in a pulse-train. PWM applications include controlling servos and speed controllers and limiting the power of motors.

What are UART Pins?

Universal Asynchronous Receiver/Transmitter (UART) pins are used for serial communication. The RX pin is used to receive the data and the TX to send.

What are I2C Pins?

Inter-Integrated Circuits (I2C) pins are used for sending and receiving data. The Serial Clock (SCL) pin is used for synchronizing. The Serial Data (SDA) pin is used for sending and receiving the data.

What are SPI pins?

Serial Peripheral Interface (SPI) pins are used to quickly communicate with peripheral devices or another microcontroller over short distances .

ISCP Header

In-Circuit Serial Programming (ICSP) header is use for  SPI communication and to program a microcontroller without disconnecting the microcontroller from the circuit.


The ATMega32U4, developed by Atmel, is a 8-bit AVR RISC-based microchip with 32KB self-programming flash memory, 2.5KB SRAM, 1KB EEPROM, USB 2.0 full-speed/low-speed device, 12-channel 10-bit A/D-converter and a JTAG interface for on-chip-debugging.

Audrino Micro Variation 1 Pinout

Audrino Micro Dimensions

Figure 1. Arduino Micro Dimensions
Figure2: Arduino Micro Variation 1 Dimensions

Technical Specifications

Microcontroller ATmega32U4
Operating Voltage 5V
Input Voltage (recommended) 7-9V
Input Voltage (limit) 6-9V
Digital I/O Pins 20
PWM Channels 7
Analog Input Channels 12
DC Current per I/O Pin 20 mA
DC Current for 3.3V Pin 50 mA
Flash Memory 32 KB (ATmega32U4) of which 4 KB used by bootloader
SRAM 2.5 KB (ATmega32U4)
EEPROM 1 KB (ATmega32U4)
Clock Speed 16 MHz
Length 48 mm
Width 18 mm
Weight 13 g