Inspired by the October 6, 2022 Hackaday blog post "Seven Segments, But Not As We Know Them," this project uses the same slider-controlled seven-segment display concept to make a fun but impractical numerical input system.
The system consists of modules, each of which is one seven-segment digit. The modules plug together to make an input device of the desired size. To input a value, the user manipulates three mechanical sliders on each module to set the value in that module's display. An Arduino plugged into the device can then read digits the user has set.
Each module has seven Hall effect sensors to read the slider positions. Their values are loaded into an 8-bit shift register in the module. Plugging the modules together daisy-chains the shift registers so that an Arduino plugged into the end of the chain can shift the state of every sensor in the device out one bit at a time.
To make reading devices easy, the project has an Arduino library.
I'm glad you like it.
Yes, I'm sure it could be motorized to make it do both input an output, I agree, racks and pinions with three steppers is probably the most straightforward approach. It seems like there ought to be a less more surprising, lower part count way. Definitely worth thinking about.