There are several, new, interesting microcontrollers that are available as well as a number of existing ones.

Quick list:

• Micro:bit – A BBC/Microsoft collaboration which was developed for STEM education.  This is a very capable and inexpensive device with excellent support.  It can be programmed via a graphical interface, using JavaScript, or Python.  Check it out at: http://microbit.org/
• Sino:bit – This is also a STEM learning tool, but this one is from China and sports a larger LED array.  Check out:  https://www.elecrow.com/sino-bit-v1-0.html or https://learn.adafruit.com/sino-bit-with-arduino/dastels-overview
• Circuit Playground Express – This board can be programmed using the MakeCode environment in the graphical editor, JavaScript, or Python, just like the Micro:bit.  Check out:  https://learn.adafruit.com/adafruit-circuit-playground-express?view=all
• Feather and Trinket, also from AdaFruit and they can be programmed with on-board Python.

Raspberry Pi Family:

There is a new addition to the Pi line of microcontrollers, the ASUS Tinker Board. It is faster and has more memory than the Raspberry Pi 3 B+, so it feels pretty zippy when working with it. The larger question is whether the additional performance justifies the higher price. Preliminary work with it shows that it is very effective as a small Linux machine, so if the application requires performance, the price is probably fine. For teaching microcontrollers, it seems a bit pricey since performance is generally not as critical in such an application. Also, there are some really good tools for STEM teaching available from UC Davis which don’t currently run on the Tinker Board. (Check out: http://c-stem.ucdavis.edu/)