Writing messages using persistence of vision

Persistence of vision (POV) displays can produce an almost magical effect, displaying images in the air by moving a line of LEDs back and forth very quickly or around in circles. The effect works because your eyes are unable to adjust fast enough to separate out the individual flashes of light, and so you observe a merged image (the message or picture being displayed):

Persistence of vision using RGB LEDs

Getting ready

This recipe uses the RGB LED kit used in the previous recipe; you will also need the following additional items:

• Breadboard (half-sized or larger)
• 2 x DuPont female-to-male patch wires
• Tilt switch (the ball-bearing type is suitable)
• 1 x 470 ohm resistor (R_Protect)
• Breadboard wire (solid core)

The tilt switch should be added to the RGB LED (as described in the Getting ready section of the Multiplexed color LEDs recipe). The tilt switch is wired as follows:

The tilt switch is connected to GPIO Input (GPIO pin 24) and Gnd (GPIO pin 6)

To reproduce...