Arduino Basic Knowledge

Arduino Micro Specifications/Functions

In this article, we will explain in detail the specifications and functions of Arduino Micro.

The Arduino Micro is a smaller Arduino board compared to the Arduino Uno. It can be used by inserting it directly into the breadboard.

Arduino Micro Specifications

Tech Specs Arduino Micro
Board Size 48.2×17.8mm
Microcontroller/
Clock Speed
ATmega32U4/
16MHz
SRAM
(Main Memory)
2.5kB
Flash Memory 32kB
EEPROM 1kB
Operating Voltage +5V
Input Voltage (recommended) +7~+12V
Output Voltage +5V, +3.3V
Digital I/O Pins 24
PWM Digital I/O Pins 7
Analog Input Pins 12
Analog Output Pins
(DAC)
Rated Current per Pin 40mA/Pin
Program Writing Pins Micro USB Type-B
ICSP
Interface UART
I2C
SPI


For the specifications of Arduino boards other than Arduino Micro, see the following article.

Arduino Micro Functions

Arduino Micro Appearance

Pin Header Placement/LED Placement

Arduino Micro Pin Header LED Placement

↑Click to enlarge.

①Microcontroller(Microcomputer)

The Arduino Micro Microcontroller(Microcomputer) uses “ATmega32U4” from Microchip Technology(USA).

A microcontroller(microcomputer) is a very important component in controlling electronic devices that correspond to the human “brain”.

In addition, various memories such as SRAM, Flash memory, and EEPROM are also built into the microcontroller.

②USB Port

You can communicate between Arduino Micro and PC by connecting it to the USB port of Arduino Micro and PC with a USB cable.

You can write a program(sketch) created on your PC to Arduino Micro, and control Arduino Micro from your PC by serial communication.

It also has the role of powering the Arduino Micro via USB, as it doesn’t have a power jack like the Arduino Uno.

③Rest Button

You can restart the Arduino Micro by pressing the reset button. Use this when you want to restart the program from the beginning or when the Arduino Micro behaves strangely.

④I/O Port・Power

Digital I/O・PWM

Digital I/O・PWM Explanation
D0-D23 Digital input/output(0-23)
HIGH(+5V)/LOW(0V)
PWM 0 to +5V analog output
Analog output by switching between 0V and +5V at high speed


PWM and serial communication are shared with digital I/O. You can specify which one to use in the program.

Analog Input

Analog Input Explanation
A0-A11 Analog input(0-11)
10-bit A/D converter(1step change every 4.8mV)


Communication

Communication Explanation
UART
(Serial communication)
TX Serial data transmission
RX Serial data reception
I2C SCL Serial clock
SDA Serial data transmission/reception
SPI SS Select device to control
SCK Serial clock
MOSI Master ⇒ Slave data transfer
MISO Slave ⇒ Master data transfer


Power

Power Explanation
Vin The voltage of “②USB Port” is output,
Power can be supplied from “Vin” without using the USB Port.
GND Ground/Reference point
+5V +5V voltage output
+3.3V +3.3V voltage output

Other

Other Explanation
GND Ground/Reference point
AREF Analog input reference voltage (0 to +5V input),
Not normally used
RESET Reset
(Same function as “③Reset Button”)

⑤LED

LED Explanation
ON Lights up when the Arduino Micro is powered
TX Blinks when sending via serial communication
RX Blinks when receiving via serial communication
L Connect to digital I/O No.13


Arduino Micro has 4 LEDs(chip parts). The “L” of LED is connected to the 13th digital I/O, and can be lighted up by setting the 13th pin to HIGH (5V) in the program.

⑥ICSP(For ATmega32U4)

By connecting an ICSP-compatible writer(program writing device), you can write programs(sketches) directly to the “ATmega32U4”, which is an Arduino Micro microcontroller(microcomputer).

However, since you can usually write programs(sketches) via the USB port, I think that it is rarely used for writing purposes.

In addition, it can also be used as an SPI terminal.

How to get technical data for Arduino Micro

Various technical materials of Arduino Micro can be obtained from the official Arduino website.

Arduino Micro Technical Data
  • EAGLE FILES
  • SCHEMATICS: PDF Format
  • BOARD SIZE Data: DXF Format
  • FRITZING FILE
2

Arduino Micro DOCUMENTATION

Click “DOCUMENTATION”.

3

Arduino Micro EAGLE FILES SCHEMATICS BOARD SIZE Data FRITZING FILE Download

Click each icon to download the “EAGLE FILES”, “SCHEMATICS”, “BOARD SIZE Data”, and “FRITZING FILE”.

Don`t copy text!