We’ve been frankly mystified at the popularity of fidget spinners. After all, we can flip an ink pen around just fine. However, [MakersBox] just sold us on what he calls the geek spinner. The fact that the spinner is actually a PCB and has parts on it, would probably have been cool enough. However, the spinner also has a persistence of vision LED set up and can display 12 characters of text as it spins. Because the board is simple and uses through hole components, it would be a great project for a budding young hacker. You can see a video below.
The instructions are geared towards someone attempting their first project, too. If you know how to solder and insert a DIP IC, you might find you’ll skim them, but it is pretty straightforward. The 8 LEDs on one side operate from an ATTiny CPU, which you can program with an Arduino. The spinner has a hall effect sensor and a magnet to figure out the index position of the spin — crucial for displaying text.
Although the board attempts to balance the components, the battery side is apparently a little heavy. The suggestion is to add some weight using some hardware or solder to that side. Speaking of solder, the bearing in the center solders to the PCB. That’s going to take a lot of heat, so maybe you can finally use Dad’s soldering gun that has been gathering dust under your bench.
We liked the polar graph provided to help you set up the code for your own messages. The text implies there is a picture of one of these graphs filled out, but we think he forgot to include that picture. However, it is clear enough how to use it, and it would make it very easy to make your own text or any design that the spinner could produce.
This isn’t the first POV spinner, by the way. [MakersBox] has a nice set of acknowledgments for projects he’s seen or borrowed from, but the other one he mentions uses surface mount. Granted, surface mount isn’t a problem for most people these days, but starting out, it might be nice to stick with a through-hole design. If you want a more useful spinner, you can always make some music.
Film is projected at a rate of 24 frames per second, which is sufficient to create the POV illusion. A projector’s shutter inserts itself between the lamp and the lens, blocking the light to prevent projection of the film’s physical movement. But these short periods of darkness, or flicker, present a problem. Originally, shutters were made in the shape of a semi-circle, so they block the light half of the time. Someone figured out that increasing the flicker rate to 60-70 times per second would have the effect of constant brightness. And so the modern shutter has three blades: one blocks projection of the film’s movement, and the other two simply increase flicker.
