Arduino Boards

Arduino boards are the easiest way into electronics: plug one into USB, open the free Arduino IDE, and upload a sketch in minutes.

The Uno R3 is the classic choice. It has an ATmega328P at 16 MHz, 5V logic, 14 digital pins (PWM on 3, 5, 6, 9, 10 and 11) and 6 analog inputs, with I2C on A4/A5 and SPI on D10-D13. The Nano uses the same chip in a breadboard-friendly size, with two extra analog pins. The Mega 2560 adds far more pins and serial ports for projects with many sensors and motors. The Uno R4 moves to a 32-bit 48 MHz chip with more memory.

How to choose:

  • Pick the Uno for learning and shields.
  • Pick the Nano for compact builds on a breadboard.
  • Pick the Mega when you run out of pins.

Most low-cost boards use a CH340 USB chip, which needs a one-time driver on some computers but runs the same code, libraries and shields. Because Arduino boards use 5V logic, they work directly with most classic sensor modules. Keep each pin under about 20 mA and the whole board under about 200 mA.

Frequently asked questions

Do Arduino-compatible boards run the same code?

Yes. They use the same IDE, libraries and shields. CH340 boards may need the CH340 driver once.

Uno or Nano?

Same ATmega328P and speed. The Nano is smaller, fits a breadboard and has two extra analog pins. The Uno takes shields.

When do I need a Mega?

When a project needs more pins or serial ports than the Uno has, for example several sensors, motors and a display at once.

How much current can an Arduino pin supply?

About 20 mA per pin and about 200 mA in total. Drive motors and relays through a driver or transistor.

Guides

Reference pages on soldr.ai

More guides on soldr.ai

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