Comparing Arduino Boards

Arduino boards is large and proliferating – the Arduino website alone lists 20 different versions.

Before proceeding with an overview of some of the more widely used Arduino boards, it’s worth mentioning that, for beginners especially, it is advisable to purchase an Arduino starter kit. These contain a comprehensive range of additional components and accessories such as shields (expansion boards) to enable users to complete the projects they have in mind.

The most basic board, and the one usually favoured by Arduino novices, is the Arduino Uno. It comes with an ATMega328 chip which, while adequate for relatively simple tasks, is not well suited to more advanced or intricate projects, largely because it has very limited flash memory and SRAM. This means that it simply cannot manage the scale and intricacy of the programs needed to operate a display or to store image or audio data.

The ATmega328 microcontroller is, however, easily removable from the Uno and can equally easily be replaced with another in the event of damage. The Uno is also compatible with considerably more Arduino shields than just about any other board available.

Whereas the Uno has just 32KB of flash memory and 2KB of SRAM, the Arduino Mega microcontroller board, with its gutsy ATmega1280 chip, comes packed with a hefty 128KB of flash memory for storing code and 8KB of SRAM. It also sports 54 digital I/O pins and 16 analogue inputs, plus 4 hardware serial ports (UARTs). The board has a reset button, a power jack and a USB connection and can be powered with a USB cable to a PC or with an AC to DC adapter.  It is compatible with the vast majority of the add-on shields used with the Arduino Diecimila and Duemilanove microcontroller boards.

One of the smaller microcontroller boards in the Arduino range, the Arduino Nano is based on the ATmega328 (which has 32KB of flash memory) and the ATmega168 (which has 16KB of flash memory). It has approximately the same capabilities as the Duemilanove, and is breadboard-friendly despite its miniature dimensions. Unlike the Duemilanove, however, it does not possess a DC power jack and requires a Mini-B USB cable, not a standard-sized USB.

The Arduino Robot is so named because it actually is a small robot, consisting of both a motor board and a control board, each of which possess the ATmega32u4 processor (which is also found on the Arduino Leonardo board). The lower board comes equipped with wheels, infrared sensors and a battery compartment, while upper board features a speaker, a compass chip, an LED screen and LED lights.

While additional plug-in shields can be connected, the Robot is considerably more preconfigured than just about all of the other Arduino microcontrollers in order to operate the robot as planned (many of its pins are pre-mapped onto integral sensors and actuators). For users who would prefer to have the flexibility of designing their own custom made robots, better options may be either the Uno or the Leonardo boards (additional shields would then need to include motor controls, actuators and servos). The Robot control board has 32KB of flash memory and 2.5KB of SRAM.


Technical aspects illustrating technical differences

Arduino Uno

  • Processor: ATmega328
  • Operating voltage: 5V
  • Flash memory 32KB
  • SRAM 2KB;
  • Digital I/O pins: 14
  • Analogue I/O pins: 6
  • clock speed 16MHz


Arduino Mega

  • Processor: ATmega1280
  • Operating voltage: 5V
  • Flash memory 128KB
  • SRAM 8KB
  • Digital I/O pins: 54
  • Analogue I/O pins: 16
  • Clock speed: 16 MHz


Arduino Nano

  • Processor: Atmel ATmega168 or ATmega328
  • Operating voltage: 5V
  • Flash memory 16 KB (ATmega168) or 32 KB (ATmega328)
  • SRAM 1 KB (ATmega168) or 2 KB (ATmega328)
  • Digital I/O pins: 14
  • Analogue I/O pins: 8
  • Clock speed: 16 MHz


Arduino Robot: Flash memory: 32KB; SRAM 2.5KB;

  • Processor: ATmega32u4
  • Operating voltage: 5V
  • Flash memory 32KB
  • SRAM 2.5 KB
  • Digital I/O pins: 5
  • Analogue I/O pins: 4 (plus 8 multiplexed)
  • Clock speed: 16 MHz


How the boards differ

The boards differ from one another in the amount of SRAM and flash memory they possess, the add-on shields they are compatible with, and the number of I/O pins available.


Current product advantages and limitations

The chief limitation of the more basic Arduino boards is their limited flash memory for data storage. However, with more powerful processors, and an extensive array of add-on shields, Arduin boards have an almost limitless span of applications.


Development Product examples

Arduino boards, beyond their massive uptake by hobbyists and DIY enthusiasts, are increasingly being used to prototype commercial products, to customise scientific equipment and control lighting systems in response to variations in ambient light, as well as to provide software and hardware in drones and function as trip computers in automobiles.

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