Sometimes projects call for a wee small microcontroller board. These products are cost effective solutions when you just want to do a few things, like read a few buttons and drive some NeoPixels, or in using them for wearable projects.

This page contains all of the diminutive CircuitPython compatible boards and a bit about the features of each one. You know you want a tiny board, now to figure out what other features will work best for you!

CircuitPython BLE support on ESP32-S3 is not yet complete, as of CircuitPython 9.x.

QT Py

Easily interface to STEMMA QT / Qwiic sensors and breakouts. They are the same size, form factor and pinout as the Seeed Xiao. 

There are a number of QT Py boards with different processors to suit your project.

SAMD21

The Adafruit QT Py uses an ATSAMD21 microcontroller, has 11 GPIO pins, a built in RGB NeoPixel LED, and a USB Type C connector. The QT Py SAMD21 has limited RAM, but it's fine for small projects. It also has no external flash, but there is an optional SOIC-8 SPI Flash chip footprint on the bottom. 

Animation of Adafruit QT Py with onboard NeoPixel in a rainbow swirl.
What a cutie pie! Or is it... a QT Py? This diminutive dev board comes with our favorite lil chip, the SAMD21 (as made famous in our GEMMA M0 and Trinket M0 boards).This time it...
$7.50
In Stock

RP2040

The Adafruit QT Py RP2040 uses a Raspberry Pi RP2040 microcontroller. It has 11 GPIO pins, a built in RGB NeoPixel LED, and a USB Type C connector.

Video of hand holding a QT Py PCB in their hand. An LED glows rainbow colors.
What a cutie pie! Or is it... a QT Py? This diminutive dev board comes with one of our new favorite chip, the RP2040. It's been made famous in the new
$9.95
In Stock

ESP32-S3

The Espressif ESP32-S3 has native WiFi capabilities and dual processor cores like the ESP32, while supporting both WiFi and Bluetooth. It is well supported by CircuitPython.

Angled shot of purple, square-shaped microcontroller.
The ESP32-S3 has arrived in QT Py format - and what a great way to get started with this powerful new chip from Espressif! With dual 240 MHz cores, WiFi and BLE support, and native...
$12.50
In Stock
Angled shot of small purple microcontroller.
The ESP32-S3 has arrived in QT Py format - and what a great way to get started with this powerful new chip from Espressif! With dual 240 MHz cores, WiFi and BLE support, and native...
$12.50
In Stock

The ESP32-S3 is more recent than this ESP32-S2, has dual cores and additional features.

ESP32-S2

The Espressif ESP32-S2 has native WiFi capabilities like the ESP32, but it only has a single processor core and does not have Bluetooth. However, it does have native USB support, and thus is the first all-in-one WiFi chip with CircuitPython support.

Angled shot of small square purple dev board.
What has your favorite Espressif WiFi microcontroller, comes with our favorite connector - the STEMMA QT, a chainable I2C port, and has...
$12.50
In Stock
Angled shot of purple square-shaped microcontroller with a uFL antenna attached.
What has your favorite Espressif WiFi microcontroller, comes with our favorite connector - the STEMMA QT, a chainable I2C port, and has...
$12.50
In Stock

QT Py is a good choice if you want an easy way to interface to STEMMA QT / Qwiic connected sensors in the smallest board size. Adafruit recommends the ESP32-S3 products over the ESP32-S2 boards due to ESP32-S3 having dual cores and additional features.

ItsyBitsy Boards

A nice step up from the Trinket M0 with tons more GPIO pins.

ItsyBitsy RP2040

The Adafruit ItsyBitsy RP2040 combines the small ItsyBitsy form factor with the powerful Raspberry Pi RP2040 microcontroller, all for a low price. It has 8MB SPI Flash memory for lots of storage along with 23 GPIO pins.

Video of hand holding an ItsyBitsy PCB. An on-board LED glows rainbow colors.
A new chip means a new ItsyBitsy, and the Raspberry Pi RP2040 is no exception. When we saw this chip we thought "this chip is going to be awesome when we give it the ItsyBitsy...
$9.95
In Stock

An powerful dual core processor with lots of storage, CircuitPython and Arduino capabile at a low price point.

ItsyBitsy M0 Express

The Adafruit ItsyBitsy M0 Express uses an ATSAMD21 microprocessor. It has 2 MB of SPI flash, a little red LED, a RGB DotStar LED, and 23 GPIO pins. It includes special Vhigh output pin to give you the higher voltage for driving NeoPixels, servos, and other 5V-logic devices directly.

Angled shot of Adafruit ItsyBitsy M0 Express - for CircuitPython & Arduino IDE.
What's smaller than a Feather but larger than a Trinket? It's an Adafruit ItsyBitsy M0 Express! Small, powerful, with a rockin' ATSAMD21 Cortex M0...
$11.95
In Stock

This is an excellent choice for getting started with soldering and breadboarding.

ItsyBitsy M4 Express

The ItsyBitsy M0's big sister.

The Adafruit ItsyBitsy M4 Express uses a more powerful ATSAMD51 microprocessor. It has 2 MB of SPI flash, a little red LED, a RGB DotStar LED, and 23 GPIO pins. It includes special Vhigh output pin to give you the higher voltage for driving NeoPixels, servos, and other 5V-logic devices directly.

Adafruit ItsyBitsy M4 Express featuring ATSAMD51 connected to a small breadboard.
What's smaller than a Feather but larger than a Trinket? It's an Adafruit ItsyBitsy M4 Express featuring the Microchip ATSAMD51! Small,...
$14.95
In Stock

This is an excellent choice for getting started with soldering and breadboarding.

ItsyBitsy nRF52840 Express

The ItsyBitsy M0 and M4's cool cousin with Bluetooth.

The Adafruit ItsyBitsy nRF52840 makes it easy to add Bluetooth to smaller projects or projects with smaller spaces. It includes special Vhigh output pin to give you the higher voltage for driving NeoPixels, servos, and other 5V-logic devices directly.

Angled shot of Adafruit ItsyBitsy nRF52840 Express - Bluetooth LE.
What's smaller than a Feather but larger than a Trinket? It's an Adafruit ItsyBitsy nRF52840 Express featuring the Nordic nRF52840 Bluetooth LE...
$19.95
In Stock

This is an excellent choice for getting started with soldering and breadboarding - with bonus Bluetooth capability.

ItsyBitsy ESP32

The ItsyBitsy ESP32 contains a dual core processor with WiFi.

The ESP32 boards come with either an integrated antenna or an external antenna connector. They both have a dual-core processor and 8MB Flash and 2MB PSRAM along with STEMMA QT I2C expansion connectors. The USB connector is NOT native USB so it cannot act as a USB keyboard. 

Angled shot of black, rectangular microcontroller.
What's smaller than a Feather but larger than a Trinket? It's an Adafruit ItsyBitsy ESP32, a powerful processor PCB with a plethora of pins! It features...
$14.95
In Stock
Angled shot of black, rectangular microcontroller.
What's smaller than a Feather but larger than a Trinket? It's an Adafruit ItsyBitsy ESP32 with a wFL external Antenna Connection, a powerful...
$14.95
In Stock

Best used with Arduino, CircuitPython use would be for advanced users only.

Adafruit KB2040 - RP2040 Kee Boar Driver

The power of the Raspberry Pi RP2040 microcontroller in an Arduino Pro Micro form factor for super-duper keyboard processing and more.

Angled shot of short black microcontroller.
A wild Kee Boar appears! It’s a shiny KB2040! An Arduino Pro Micro-shaped board for Keebs with RP2040. (#keeblife 4 evah) A lot of folks like using Adafruit...
$8.95
In Stock

While the Arduino Pro Micro became a popular keyboard controller due to native USB, the processor is older than the current generation of chips. The KB2040 is a drop-in replacement which has a super fast dual-core processor with a juicy 8MB of Flash memory for using with many types of firmware including KMK based on CircuitPython. Bring your project into the current decade!

Planning a keyboard project or like the form factor, this is the board you want to look at.

Trinket M0

A very minimalist board with only 5 GPIOs.

The Adafruit Trinket M0 runs the ATSAMD21 microprocessor, has 5 GPIO pins, a little red LED and an RGB DotStar LED. This is a low cost option when you're looking to get started, or want to put together a project on a budget. It is pin compatible with the earlier (non-M0) Trinket, and a lot of projects can be upgraded with this board

Manicured hand holding Trinket M0.
The Adafruit Trinket M0 may be small, but do not be fooled by its size! It's a tiny microcontroller board, built around the Atmel ATSAMD21, a little chip with a lot...
$8.95
In Stock

This is a choice if you want the most minimal option.

GEMMA M0

Think of this as a wearable version of the Trinket M0.

Looking to add NeoPixels to your wearables or cosplay outfits? This board is the easiest way to do so.

Pink polished fingers holding a Adafruit GEMMA M0 - Miniature wearable electronic platform.
The Adafruit Gemma M0 is a super small microcontroller board, with just enough built-in to create many simple projects. It may look small and cute: round, about the...
$9.95
In Stock

The Adafruit GEMMA M0 run the ATSAMD21 microcontroller, an on/off switch, and a RGB DotStar LED. It has three input/output big-hole sew-pads that can be used for conductive thread, or alligator clips for fast prototyping. It can be powered via USB or through the JST battery connector (though it doesn't have charging capability).

It is pin compatible with the earlier (non-M0) Gemma, and a lot of projects can be upgraded with this board

This is a choice if you want the most minimal wearable option.

This guide was first published on Nov 18, 2020. It was last updated on Apr 23, 2024.

This page (Tiny Boards) was last updated on Apr 23, 2024.

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