Persistence of Vision (POV) Device

The project imitates the way a television works wherein an image or series of colors are blended together due to the occurrence of light pulses at a speed faster than the eyes can perceive.

The design of the circuit consists of 8 LEDs that are connected to a single port of the microcontroller. The individual lines can be selected for each segment as time proceeds. The time between the letters is being set using the variable VAR, which is a simple way to tweak the project. In theory, the bottom of the loop can be determined by using an accelerometer to restart the program. To make a varying analog value, a potentiometer is used in this case while directly connecting to an ADC. The refresh rate can be speed up/down with the twist of a screwdriver.

The device is being powered by 3 AAA cells or 3.7V lithium battery. The microcontroller used in this project is the Atmel AVR Mega48 to accommodate the 16 LEDs using 2 ports. The refresh rate can be varied by a potentiometer, since the timing of the POV’s refresh rate or cycle rate is dependent on specific value.