Arduino Uno R3 Specifications/Functions

In this article, we will explain in detail the specifications and functions of Arduino Uno R3(Arduino Uno).

Arduino Uno is the most representative and basic edition of the more than 20 editions.

TOC

Arduino Uno Specifications

Tech SpecsArduino Uno
Board Size74.9×53.3mm
Microcontroller/
Clock Speed
ATmega328P/
16MHz
SRAM
(Main Memory)
2kB
Flash Memory32kB
EEPROM1kB
Operating Voltage+5V
Input Voltage
(recommended)
+7~+12V
Output Voltage+5V, +3.3V
Digital I/O Pins20
PWM Digital I/O Pins6
Analog Input Pins6
Analog Output Pins
(DAC)
Rated Current per Pin40mA/Pin
Program Writing PinsUSB Type-B
ICSP
InterfaceUART
I2C
SPI

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

Arduino Uno Functions

Arduino Uno Appearance

Socket Header Placement(Pin Header Placement)/LED Placement

Arduino Uno Pin Header LED Placement

↑Click to enlarge.

①Microcontroller(Microcomputer)

The Arduino Uno Microcontroller(Microcomputer) uses “ATmega328P” 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 Uno and PC by connecting it to the USB port of Arduino Uno and PC with a USB cable.

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

You can also power the Arduino Uno via USB instead of the power jack.

③Power Jack

You can connect an AC adapter(outer diameter 5.5mm, inner diameter 2.1mm) to power the Arduino Uno.

④Reset Button

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

⑤I/O Port・Power

Digital I/O・PWM

Digital I/O・PWMExplanation
D0-D19Digital input/output(0-19)
HIGH(+5V)/LOW(0V)
PWM0 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 InputExplanation
A0-A5Analog input(0-5)
10-bit A/D converter(1step change every 4.8mV)

Communication

CommunicationExplanation
UART
(Serial communication)
TXSerial data transmission
RXSerial data reception
I2CSCLSerial clock
SDASerial data transmission/reception
SPISSSelect device to control
SCKSerial clock
MOSIMaster ⇒ Slave data transfer
MISOSlave ⇒ Master data transfer

Power

PowerExplanation
VinThe voltage of “③Power jack” is output,
Power can be supplied from “Vin” without using the power jack.
GNDGround/Reference point
+5V+5V voltage output
+3.3V+3.3V voltage output

Other

OtherExplanation
GNDGround/Reference point
AREFAnalog input reference voltage (0 to +5V input),
Not normally used
RESETReset
(Same function as “④Reset Button”)
IOREF+5V voltage output

⑥LED

LEDExplanation
ONLights up when the Arduino Uno is powered
TXBlinks when sending via serial communication
RXBlinks when receiving via serial communication
LConnect to digital I/O No.13

Arduino Uno 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.

⑦ICSP

Arduino Uno has two ICSP terminals, for “ATmega328P” and “ATmega16U2”.

For ATmega328P

By connecting an ICSP-compatible writer(program writing device), you can write programs(sketches) directly to the “ATmega328P”, which is an Arduino Uno 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.

For ATmega16U2

By connecting an ICSP-compatible writer(program writing device), you can write sketches(programs) directly to the “ATmega16U2”, which is USB-serial conversion IC of Arduino Uno.

Therefore, you can create a device for USB, but it is rarely used because it cannot be written by the Arduino IDE.

How to get technical data for Arduino Uno

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

Arduino Uno Technical Data
  • EAGLE FILES
  • SCHEMATICS: PDF Format
  • BOARD SIZE Data: DXF Format
2
Arduino Uno DOCUMENTATION

Click “DOCUMENTATION”.

3
Arduino Uno EAGLE FILES SCHEMATICS BOARD SIZE Data Download

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

Let's share this post!
TOC
閉じる