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!
Easily interface to STEMMA QT / Qwiic sensors and breakouts.
The Adafruit QT Py uses an ATSAMD21 microcontroller, has 11 GPIO pins, a built in RGB NeoPixel LED, and a USB Type C connector, in the same size, form factor and pinout as the Seeed Xiao. There is an optional SOIC-8 SPI Flash chip footprint on the bottom. The built in STEMMA QT connector makes it super simple to use any of the available STEMMA QT sensors and breakouts with no soldering required.
This is a good choice if you want an easy way to interface to STEMMA QT / Qwiic connected sensors.
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
This is a good choice if you want the most minimal option.
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.
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 good choice if you want the most minimal wearable option.
A nice step up from the Trinket M0 with tons more GPIO pins.
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.
This is an excellent choice for getting started with soldering and breadboarding.
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.
This is an excellent choice for getting started with soldering and breadboarding.
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.
This is an excellent choice for getting started with soldering and breadboarding - with bonus Bluetooth capability.
