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.
Arduino Uno Specifications
|Tech Specs||Arduino Uno|
|Input Voltage (recommended)||+7～+12V|
|Output Voltage||+5V, +3.3V|
|Digital I/O Pins||20|
|PWM Digital I/O Pins||6|
|Analog Input Pins||6|
|Analog Output Pins
|Rated Current per Pin||40mA/Pin|
|Program Writing Pins||USB Type-B
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
↑Click to enlarge.
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.
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.
You can connect an AC adapter(outer diameter 5.5mm, inner diameter 2.1mm) to power the Arduino Uno.
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.
|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.
10-bit A/D converter(1step change every 4.8mV)
|TX||Serial data transmission|
|RX||Serial data reception|
|SDA||Serial data transmission/reception|
|SPI||SS||Select device to control|
|MOSI||Master ⇒ Slave data transfer|
|MISO||Slave ⇒ Master data transfer|
|Vin||The voltage of “③Power jack” is output,
Power can be supplied from “Vin” without using the power jack.
|+5V||+5V voltage output|
|+3.3V||+3.3V voltage output|
|AREF||Analog input reference voltage (0 to +5V input),
Not normally used
(Same function as “④Reset Button”)
|IOREF||+5V voltage output|
|ON||Lights up when the Arduino Uno 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 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.
Arduino Uno has two ICSP terminals, for “ATmega328P” and “ATmega16U2”.
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.
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.
- EAGLE FILES
- SCHEMATICS: PDF Format
- BOARD SIZE Data: DXF Format
First, go to the Arduino official website from the link below.
Click each icon to download the “EAGLE FILES”, “SCHEMATICS”, and “BOARD SIZE Data”.