My POV business card! video links below: [Persistence-of-Vision (POV) is the lingering effect of bright lights on the eyes, and when a 1D array is swept around rapidly it appears to create a 2D image] The operator simply swings the card back and forth as a simple ball-tilt sensor detects the shake cadence and direction. The LED pattern plays through when swung and reverses the pattern on the back stroke which reinforces the POV effect. The timing of the LED pattern adjusts based on how fast/slowly the user is swinging the card. Ver1: discrete white LEDs which I had to solder by hand to an AT2313. It also had a photoresistor for a 'dark detector' mode. https://youtu.be/G_Iy9dcu5aQ?si=bN6PfmL506gzJxt8 Ver2: redesigned with RGB neoPixel strip. Requires much less labor soldering since the strip only needs 1 data wire, I could downsize to an ATtiny 85! https://youtu.be/3PiGIascq4Y?si=Mv9_nLt16IdpDQg4 my other projects: https://asaweiss.com/