As the HackADay crew notes, the DIY project is a great example of a Maker cheerfully modding whatever material and components happen to be readily available.
“Martin2250 is using an IR LED and photodiode to determine the rotational speed of the disc. He [initially] tried using the Arduino micros() function to delay between the photodiode pulse and turning on his LEDs,” explained HackADay’s Adam Fabio. “[However], he’s since switched over to using the AVR’s native timers.”
The disc is in the above-mentioned build is actually a CD, with Martin2250 diligently sanding away the label, masking out his digits and painting with a black marker. Meanwhile, cardboard, hot glue and visible LEDs were used to create four light boxes for the digits.
“The disc can display any four digits at once – perfect for a POV clock. We [also] love the use of on-hand materials in this hack – bits of hard and balsa wood, liberal use of hot glue, and of course cardboard,” added Fabio.
Interested in learning more about the Atmel-Arduino powered POV display? You can check out Martin2550’s Reddit post here.