I built an LED matrix board for a future project. I designed it so multiple boards can be strung together to form a larger display. I also used SMT for the design. There are no mounting options save for hot melt adhesive. It uses the popular MAX7219 driver chip and one resistor.
Useless Machine
If you do a Google search for useless machine you will see a bunch of these. I saw several people’s useless machines and I wanted one so, I made one. I used a small servo, 3 AA Batteries, and a simple 555 circuit to control the servo. It was a quick and dirty build but it works.
Resistor Grid
The infinite resistor grid problem is interesting and I thought it might look nice on my wall so I built one. I made a quick jig out of wood and went to work. I spent my free time on this for a few weeks. The final piece is not quite as elegant as I had hoped but it’s still neat.
NTP Wall Clock
Uses real POE and NTP for wall clock. Might use e-paper display but probably 7 segment display or LED matrix.