Arduino Uno Developer Arduino Microcontroller ATmega328P Frequency 16 MHz

The Arduino Uno is an open-source hardware design, single-board microcontroller, Arduino based on the ATmega8, ATmega168, or ATmega328 microcontroller developed by Atmel. While currently the Arduino Uno is generally shipped with ATmega328, it is compatible with the 8 or 168 ATmega versions without modifications, including the pin configuration. The board was first announced on September 24, 2010.

The Arduino Uno is currently on its third revision.

Revision 3

In revision 3, the ATmega8U chip that was responsible for the USB communication was replaced by the ATmega16U, doubling the flash memory to 16kB from 8kB. The reset button has been moved from the center of the board to the corner right next to the USB connector.

Programming

Programming on the Ardunio Uno, like all the other Ardunio boards can be done using C and the Arduino standard libraries.

Memory

The standard design board comes with the ATmega328P which has 32 KB of flash memory, 2 KB of SRAM, and 1 KB of EEPROM.

Pinout

The board includes 13 multi-purpose digital pins and 6 multi-purpose analog pins.

Pin	Name	Description
0	RX	Receive TTL serial data
1	TX	Transmit TTL serial data
2		External interrupt, digital pin
3		External interrupt, PWD, digital pin
4		digital pin
5		PWM, digital pin
6		PWM, digital pin
7		digital pin
8		digital pin
9		PWM, digital pin
10	SS	PWM, digital pin, SPI SS (Slave Select) pin
11	MISI	PWM, digital pin, SPI MOSI (Master Out Slave In) pin
12	MOSI	digital pin, SPI MISO (Master In Slave Out) pin
13	LED/SCK	Built-in LED, digital pin, SPI SCK (Serial Clock) pin
A0		Analog pin
A1		Analog pin
A2		Analog pin
A3		Analog pin
A4	SDA	Analog pin, I²C SDA (Serial Data Line) pin
A5	SCL	Analog pin, I²C SCL (Serial Clock) pin
AREF	AREF	Reference voltage for the analog inputs
Reset	Reset	Resets the microcontroller

See also

• Arduino
• Arduino standard libraries