Neopixels are RGB LEDs sold by an electronics company called Adafruit. The modules come in different shapes and can contain any number of RGB LEDs. Each LED can be controlled (or addressed) individually. The microbit can drive around 8 LEDs; to control modules with more LEDs you’ll need to use an external 5v power source.
You can get generic, Neopixel-style modules by searching for ‘ws2812 LED’ on eBay or Amazon.
Most neopixel modules require the user to solder on their own connections. This is simple; here’s one of my modules:
Solder wires to PWR, GND and IN.
In this example the wires are colour-coded: black (for GND), red (for PWR) or yellow (for IN)
Connect the pins to the microbit. In this example, the in pin on the neopixel is connected to pin 0.
Neopixels can now be used in PXT. I’ll update this page.