This project is a simple 8-bit counter using two 4-bit counter ICs. Powered by AA batteries and connected to LEDs, it visually displays counting up to 8-bits in binary. This works as a cool little visual display that can be displayed around the house or in a MakerSpace. It has no functional purpose, it is purely for display reasons only.
This project started as a found parts project after I found some 4-bit counters in school's student run makerspace. We had a whole wall of just 74xx ICs, which I had been going through, trying to figure out some of them did and find some 7-segment display decoders. These counters caught my eye. They are cascadable, so I could go up any number I wanted, as long as I had the LEDs for it.
After finding the datasheets (these ICs were old), I started bread-boarding a 4-bit counter with LEDs connected to the outputs. With that verified, I bread-boarded two counters cascaded, still using LEDs.
The next step for this project was to build a proto-board version using a 555 timer as a clock and 3D a cage for it. This version worked well, though the external battery pack was annoying and awkward.
Enter the PCB. Based on the bread-board and proto-boarded versions, I designed a PCB to minimize the footprint.