The Feather platform has really gotten my attention recently, especially since its move to using the ATSAMD21 MCU. This is a powerhouse chip based on the ARM Cortex-M0+ core. The other great thing about Feathers is the large (and constantly growing) ecosystem of add-on boards, called FeatherWings.
Another thing I’ve enjoyed playing with are NeoPixels. I’ve used them in various formats for a variety of projects. One of the joys is that you don’t need 3 PWM outputs per LED; you just need a single digital output to drive a fairly large string of NeoPixels. Recently, a new RGB LED has been showing up in Adafruit products: the DotStar. It requires 2 outputs, but is less timing sensitive, and can be updated faster. And it is a lot smaller. The latter point is huge: it means you can pack them denser, getting more pixels in the same space. Adafruit has done just that with their DotStar Featherwing. It packs a 6x12 DotStars in the same space that fits just 4x8 NeoPixels.
In case you weren’t paying attention, a FeatherWing is only 50mm by 23mm. That’s small. Lady Ada has packed the space with DotStars so densely they almost touch. That’s enough pixels to make simple images, and display text using a simple font.
If you want to work in C/Arduino there's a guide for that. In this guide I'll be walking you through a library I wrote for using it from CircuitPython.