Before you move on, if you have no idea on what the Arduino is, you can check out our guide on What is Arduino to find out more!

Having space constraints on your Arduino Project? Need a small Arduino board?

However, there are so many small Arduino boards out there currently out there. Which one should you use?

Facing the same problem, I decided to come up with this comparison guide whereby I compare various small Arduino boards currently to find out which smallest Arduino is the best where we evaluate their capabilities and also their pros and cons.

In this comparison guide, we will cover the following smallest Arduino boards currently out there in descending order from small to smallest.

Here is the list of boards we are going to look at:

  • Nano
  • Micro
  • Pro Mini
  • Trinket – By Adafruit
  • Beetle – By DFRobot
  • Seeeduino XIAO
  • Atto – By Nionics

Without further ado, let us jump into the first board!


Arduino Nano v3

45mm x 18mm

Coming in first, we have the small, complete, and breadboard-friendly board, the Arduino Nano which is based on the same ATmega328 as the Arduino Uno. Basically, you can think of the Arduino Nano as an Arduino Uno that has been shrunk into a very small profile which makes it convenient for tight spaces and projects like wearables, mini robots and many more. If you have a code from your previous Uno project, you can easily move it to the Nano!

Operating at 16 MHz with 32KB of program memory, 1KB of EEPROM, 2KB of RAM, 14 digital I/O, 6 analog inputs and both 5V and 3.3V rails, the Arduino is packed with peripherals for its size It has more or less the same functionality of the Arduino Duemilanove, but in a different package. It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one.

However, unlike the Uno and many small Arduino boards, they cannot connect to Arduino shields but it has pin headers which makes them suitable for breadboard prototyping or in PCBs with a socket.

Need more peripherals for your Arduino Nano? Check out this Grove Shield for Arduino Nano which pulls out the pins of the motherboard and expands to 8 Grove connectors, including 3 Grove digital connectors, 3 Grove analog connectors, 1 Grove I2C connector, and 1 Grove UART connector.

With similar specs and capabilities as the Arduino Uno in a smaller size, there are many things you can do with the Nano where projects and tutorials are all well documented as they are widely used. Interested in what the Arduino Nano can do? Check out our list on the 20 Best Arduino Nano Projects that you must try now.

Specs:

SpecsArduino Nano v3
MicrocontrollerATmega328
Operating Voltage5V
Digital I/O Pins22
PWM Enable Pins6
Analog I/O pins8
Flash Memory32KB
SRAM2KB
EEPROM1KB
Clock Speed16 MHz
Size45 mm x 18 mm
Price$45.90

Want a better and cheaper Arduino Nano? We got you covered! Introducing the Seeeduino Nano!

Seeeduino Nano

The Seeeduino Nano is a compact board similar to the Seeeduino V4.2/Arduino UNO, and it is fully compatible with Arduino Nano on pinout and sizes. Compared to the Arduino Nano, the Seeeduino Nano is way cheaper at only $6.90. And best of all, it’s even better.

Firstly, would be the change of mini USB into Type-C which made is symmetrical and reversible. Secondly, would be the addition of one of our Grove I2C connectors where with the help of the Grove System, you can plug and play with hundreds of sensors and actuators!

Specs:

SpecsSeeeduino Nano
MicrocontrollerATmega328
Operating Voltage5V
Digital I/O Pins22
PWM Enable Pins6
Analog I/O pins8
Flash Memory32KB
SRAM2KB
EEPROM1KB
Clock Speed16 MHz
Size45 mm x 18 mm
Price$6.90

Arduino Micro

48mm x 18mm

Coming up next, we have the Arduino Micro. The micro is slightly bigger than the Nano and has been similarly designed to fit on a solderless breadboard. However, it is powered by the ATmega32U4 which is different from the Nano. In terms of size, it is slightly bigger than the Arduino Nano at 48mm x 18mm.

Compared to the Nano, the Micro comes with more peripherals for your project needs. With 20 digital I/O pins, 12 analog inputs, and 7 PWM enabled pins. In addition, with a native USB, you can use it as a mouse, keyboard, etc easily. However, the Micro bootloader can only be programmed with USB that requires a special driver. With Linux, only a few selective versions have the needed driver.

Basically, if you guys know the Arduino Leonardo, the Arduino Micro is a shrunk-down version of it and the Arduino Nano is a shrunk-down version of the Arduino Uno.

Specs:

SpecsArduino Micro
MicrocontrollerATmega32u4
Operating Voltage5V
Digital I/O Pins20
PWM Enabled Pins7
Analog I/O pins12
Flash Memory32 KB (4KB used by bootloader)
SRAM2.5KB
EEPROM1KB
Clock Speed16 MHz
Size48 mm x 18 mm
Price$24.90

Arduino Pro Mini

33mm x 18mm

The Arduino Pro Mini. They are basically the Arduino Pro but packed in a much smaller footprint. Connectors and USB-to-serial-converting circuitry are all removed leaving the Arduino Pro Mini with the bare minimum. In the Pro Mini, more pins are broken out from the Pro.

At such a small size, the Pro Mini definitely aren’t shield-compatible but they are breadboard-compatible with soldered on male headers. Its size also allows them to be embedded into your projects easily. When programming the Pro Mini, you will need more than just a USB cable. You will need an external board to convert USB from your desktop to serial where the Arduino can process using something like a USB CP2102 Serial Converter.

The Pro Mini comes in two varieties 5V/16MHz and 3.3V/8MHz where the 5V runs at the same voltage and speed as the Arduino Nano and Micro. With the 3V board, speed is slower and consumes lesser power which makes your board easy to power with batteries.

Specs:

SpecsArduino Pro Mini
MicrocontrollerATmega328
Operating Voltage5V / 3.3V
Digital I/O Pins14
PWM Enabled Pins6
Analog I/O pins6
Flash Memory32 KB (2KB used by Bootloader)
SRAM2KB
EEPROM1KB
Clock Speed8 / 16 MHz
Size33 mm x 18 mm
Price$9.95

Trinket M0 – By Adafruit

27mm x 15.3mm

The trinket from Adafruit has also been quite popular for its tininess measuring at around 27mm x 15.3mm. It is based on an ATSAMD21E18 chip which is one of the most powerful chip out the market. Even though this is not an Arduino, this microcontroller can be programmed with Arduino IDE and functions like one as well. In addition, the Trinket is able to be programmed by circuit python as well.

However, at such a small size, you sacrifice onboard peripherals as you can see, the Trinket only allows for 5 GPIO pins with digital input/output.

Specs:

SpecsTrinket M0
MicrocontrollerATSAMD21
Operating Voltage3.3V
Digital I/O Pins5
PWM Enabled Pins2
Analog I/O pins3
Flash Memory256 KB
SRAM32KB
EEPROM
Clock Speed48 MHz
Size27mm x 15.3 mm
Price$8.95

Beetle – By DFRobot

Ref: DFRobot

20mm x 22mm

Next, we have the Beetle which is one of the smallest Arduino Leonardo board. As it one of the smallest Leonardo boards, it is powered by ATmega32u4 which is similar to the Arduino Micro.

Standing at 20mm x 22mm, the Beetle is definitely one of the smallest Arduino boards out there in the market currently. It runs at 16MHz, with 10 digital pins, 5 analog pins, and 4 PWM pins. It is also compatible with micro USB to make it user-friendly where you can directly program and test with the board.

If you have any code from your previous Leonardo project, you can easily move it to the Beetle as it is already pre burned with a bootloader.

Similarly to the Trinket by Adafruit, having such a tiny board means you have to sacriface its onboard peripherals.

However, if you want more peripherals on your board like more I/O pins and PWM pins? An even tinier board coming up next maybe what you are looking for!

Specs:

SpecsBeetle
MicrocontrollerATmega32u4
Operating Voltage5V
Digital I/O Pins10
PWM Enabled Pins4
Analog I/O pins5
Flash Memory32 KB (4KB used by bootloader)
SRAM2.5KB
EEPROM1KB
Clock Speed16 MHz
Size20mm x 22 mm
Price$7.90

Seeeduino XIAO

20mm x 17.5mm

Coming up next for this list, we have our latest Seeeduino XIAO. It is powered by a powerful ATSAMD21, similar to the Trinket M0. With a smaller footprint and faster speed compared to most Arduino boards here, the Seeeduino XIAO is perfect to integrate into almost any projects from wearables to small robots.

Standing at only 23.5 x 17.5, this board is as small as your thumb. The Seeeduino XIAO is the smallest Arduino compatible board in Seeeduino Family. It is an Arduino microcontroller that is embedded with the SAMD21 microchip with rich interfaces as well allowing it to be capable of being a tiny Dev. Board as well.

Apart from the strong CPU, Seeeduino XIAO is excellent in many other functions. Despite being this small size, it has 14 GPIO PINs, which can be used for 11 analog PINs, 11 digital PINs, 1 I2C interface, 1 UART interface, and 1 SPI interface. Some PINs have various functions, A1/D1 to A10/D10 Pins have PWM functions and Pin A0/D0 has a function of DAC which means you can get true analog signals not PWM signals when you define it as an analog pin, that’s why 14 GPIO PINs can realize more I/O PINs and interfaces.

The board is also breadboard compatible which is very rare for a small board like this!

The Seeeduino XIAO supports the USB Type-C interface which can supply power and download code. In addition, there are power pads at the back of the XIAO which support battery and makes designing wearable devices easy and simple. Other than the power LED, we also added a user LED on board for better coding experience.

Usually a Dev. Board as small as this size will use the chip’s inner crystal oscillator for time fixing, in order to make the clock more accurate, Seeeduino XIAO layouts an extra 32.768KHz to make the clock more stable.

And of course, the Seeeduino XIAO is perfectly compatible with Arduino IDE which allows you to easily develop small projects with the help of the large and comprehensive Arduino library.

The best news is, you can get all features packed on a tiny board this just for only $4.90! Wow!

Specs:

SpecsSeeeduino XIAO
MicrocontrollerATSAMD21
Operating Voltage3.3V
Digital I/O Pins11
PWM Enabled Pins10
Analog I/O pins11
Flash Memory256 KB
SRAM32KB
EEPROM
Clock Speed48 MHz
Size23.5mm x 17.5mm
Price$4.90

Atto – By Nionics

11.5mm x 10.4mm

Lastly, we have the Atto which is probably the smallest Arduino compatible board out there standing at 11.5mm x 10.3mm. However, at such a small size, is it really powerful and capable enough to run anything?

The board, similar to the Arduino Leonardo and the previous Beetle board, is powered by ATmega32u4. Despite being so small, it has a few features which include having a reset button, integrated USB and also an RGB LED.

However, a real downside of this product is that the pins are not breadboard compatible as the pins are closer together at 0.05″ compared to the 0.1″ for the Arduino board. This means you do not have a platform where you can build and test electronic circuits. If you are want to use it with the breadboard, you would need a breadboard expansion which means more cost.

Another downside is that this product is also only currently taking pre-orders and not exactly available just yet and the price tag is slightly higher than several other boards here currently.

Specs:

SpecsBeetle
MicrocontrollerATmega32u4
Operating Voltage5V
Digital I/O Pins12
PWM Enabled Pins4
Analog I/O pins4
Flash Memory32 KB (4KB used by bootloader)
SRAM2.5KB
EEPROM1KB
Clock Speed16 MHz
Size11.5mm x 10.4 mm
Price$18.00

Summary

Finally, now you’ve known what each board is capable of, which small Arduino board is the superior one compared to the rest?

Well, unfortunately, there isn’t a best small Arduino board. But now we now know which is the smallest Arduino! However, you should pick one that fits your project needs the most! We crafted a table for you where you can easily compare their differences and pick the board that is the best for your Arduino project:

BoardMicrocontroller Operating Voltage Digital I/O Pins PWM Enabled Pins Analog I/O pins Flash Memory SRAM EEPROM Clock Speed Size Price
Arduino Nano v3 ATmega328 5V226832KB2KB1KB16MHz45 mm x 18 mm $45.90
Seeeduino Nano ATmega328 5V226832KB2KB1KB16MHz45 mm x 18 mm $6.90
Arduino Micro ATmega32u4 5V2071232KB2.5KB1KB16MHz48 mm x 18 mm $24.90
Arduino Pro Mini ATmega328 5V / 3.3V146632KB2KB1KB8 /16MHz33 mm x 18 mm $9.95
Trinket M0ATSAMD21 3.3V523256KB32KB48MHz27mm x 15.3 mm $8.95
BeetleATmega32u45V104532KB2.5KB1KB16MHz20mm x 22 mm $7.90
Seeeduino XIAO
ATSAMD21
3.3V111011256KB32KB48MHz23.5mm x 17.5mm $4.90
AttoATmega32u4 5V124 432KB2.5KB1KB16MHz11.5mm x 10.4 mm $18

In summary, which one is for you? Here are my recommendations:

Please follow and like us:
error