What a cutie pie! Or is it... a QT Py? This diminutive dev board comes with the most popular chip of the moment, the SAMD21 (as made famous in Adafruit's GEMMA M0 and Trinket M0 boards).
This low price is for a limited time only.
This time it comes with the STEMMA QT connector, a chainable I2C port that can be used with any of Adafruit's STEMMA QT sensors and accessories. All plug-and-play thanks to the innovative chainable design: SparkFun Qwiic-compatible STEMMA QT connectors for the I2C bus so you don't even need to solder! Just plug in a compatible cable and attach it to your MCU of choice, and you’re ready to load up some software and measure some light.
Use any SparkFun Qwiic boards! Seeed Grove I2C boards will also work with this adapter cable.
Pinout and shape is Seeed Xiao compatible, with castellated pads so you can solder it flat to a PCB. In addition to the QT connector, Adafruit also added an RGB NeoPixel (with controllable power pin to allow for ultra-low-power usage), and a reset button (great for restarting your program, or entering the bootloader)
Runs Arduino like a dream, and can be used for basic CircuitPython projects. For more advanced usage like datalogging or file storage, solder an SOIC SPI flash chip onto the bottom pads,