Summary of Arduino Uno Rev3
The Arduino Uno is a reference microcontroller board based on the ATmega328P, featuring 14 digital I/O pins, 6 analog inputs, and a 16 MHz clock speed. It supports programming via the Arduino IDE using a USB connection or an external programmer through the ICSP header. The board operates at 5V with an input voltage range of 7-12V recommended. Its open-source design allows users to build custom versions using available schematics, making it ideal for beginners and experienced makers alike.
Parts used in the Arduino Uno:
- ATmega328P Microcontroller
- 16 MHz Quartz Crystal
- USB Connection Port
- Power Jack
- ICSP Header
- Reset Button
- 14 Digital Input/Output Pins
- 6 Analog Input Pins
- LED_BUILTIN (Pin 13)
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Arduino Uno is a microcontroller board based on the ATmega328P (datasheet). It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started.. You can tinker with your UNO without worring too much about doing something wrong, worst case scenario you can replace the chip for a few dollars and start over again.
“Uno” means one in Italian and was chosen to mark the release of Arduino Software (IDE) 1.0. The Uno board and version 1.0 of Arduino Software (IDE) were the reference versions of Arduino, now evolved to newer releases. The Uno board is the first in a series of USB Arduino boards, and the reference model for the Arduino platform; for an extensive list of current, past or outdated boards see the Arduino index of boards.
You can find here your board warranty information.
Getting Started
You can find in the Getting Started section all the information you need to configure your board, use the Arduino Software (IDE), and start tinker with coding and electronics.
Need Help?
- On the Software on the Arduino Forum
- On Projects on the Arduino Forum
- On the Product itself through our Customer Support
| Microcontroller | ATmega328P |
| Operating Voltage | 5V |
| Input Voltage (recommended) | 7-12V |
| Input Voltage (limit) | 6-20V |
| Digital I/O Pins | 14 (of which 6 provide PWM output) |
| PWM Digital I/O Pins | 6 |
| Analog Input Pins | 6 |
| DC Current per I/O Pin | 20 mA |
| DC Current for 3.3V Pin | 50 mA |
| Flash Memory | 32 KB (ATmega328P) of which 0.5 KB used by bootloader |
| SRAM | 2 KB (ATmega328P) |
| EEPROM | 1 KB (ATmega328P) |
| Clock Speed | 16 MHz |
| LED_BUILTIN | 13 |
| Length | 68.6 mm |
| Width | 53.4 mm |
| Weight | 25 g |
OSH: Schematics
Arduino Uno is open-source hardware! You can build your own board using the following files:
Programming
The Arduino Uno can be programmed with the (Arduino Software (IDE)). Select “Arduino/Genuino Uno from the Tools > Board menu (according to the microcontroller on your board). For details, see the reference and tutorials.
The ATmega328 on the Arduino Uno comes preprogrammed with a bootloader that allows you to upload new code to it without the use of an external hardware programmer. It communicates using the original STK500 protocol (reference, C header files).
You can also bypass the bootloader and program the microcontroller through the ICSP (In-Circuit Serial Programming) header using Arduino ISP or similar; see these instructions for details.
Read more: Arduino Uno Rev3
- What does the name "Uno" signify?
The name means one in Italian and was chosen to mark the release of Arduino Software version 1.0. - How can I program the Arduino Uno board?
You can program it using the Arduino Software IDE via USB or bypass the bootloader using the ICSP header. - What is the operating voltage of the Arduino Uno?
The operating voltage is 5V. - Can I build my own Arduino Uno board?
Yes, because the hardware is open-source, you can build your own board using the provided schematics. - What happens if I damage the chip on the board?
In the worst case scenario, you can replace the chip for a few dollars and start over again. - Does the board come with preprogrammed software?
Yes, the ATmega328 comes preprogrammed with a bootloader that allows code upload without an external hardware programmer. - How many PWM outputs are available on the digital pins?
Out of 14 digital I/O pins, 6 can be used as PWM outputs. - Where can I find help for software issues?
Help is available on the Software section of the Arduino Forum.
