These are the first in a series of updated guides that were originally written for the Circuit Playground Classic and Arduino. These guides have now been updated to also work with the Circuit Playground Express and CircuitPython!
Use the light sensor to create an alarm to protect your diary from being nabbed.
Use the accelerometer to compute the height of tall objects using a drinking straw, some rubber bands, and a Circuit Playground.
Use the NeoPixels to create an hourglass style countdown timer which you can reset by “flipping” the hourglass over.