A device that can display all combinations of 4 (2x2) pixels 5cm2 (aprox. 1") with a ribbon that has 16x2 positions/pixels.
Eventually it will be a display that shows a paper pixel matrix of 8x8 pixels. with 16 (4x4) of these separate units. Every unit will be driven by a Arduino micro or nano and connected via i2c to a Uno or Mega.
Why?
First because i can and second i want to have a display that is both mechanical and holds its "value" when no power is supplied.
The strip used as a closed loop has 32pixels in two rows which when taped together can display all combinations of 2x2 black and white pixels. If someone can make it more efficient let me know.
Before the closed loop version the previous version of the display had two strips wound around a single tube (bit like a cassette tape) with a gear in the middle to drive it. I thought the tension wouldn't be much of a problem considered its a fairly short strip, but at the ends of the strip it was to tight.
If you are having trouble with your roller friction, a couple of o-rings inserted onto the rollers would help the grip. You could include a chamfered groove into the roller so the o-rings will not slide along the shaft but still stick out enough to grip.
ya know, with careful planning, you can turn that 32by2 ribbon into a 16by2 ribbon.
It would be possible to do something similar with Larger grids, but the bigger they get, the harder it is to wing it. I worked it out for 2by2, but 3by2 has 64 combinations and I need a spreadsheet to keep it organized.
Yeah I know, I wrote a script that can calculate all possible grid sizes with the least amount of pixels. but ribbon-length-wise the 2x2 is the most efficient option. A 3x3 quickly goes to about 750/2 pixels (3x2=±70x2). Or you have to make it 5x1 which will be about 49 pixels but then it would be about 1" tall and you can't get a stepper to fit in it.
Damn, that's so obvious, yet so cool. Can we somewhat cheaply make a larger scale display with this?