4-Bit Binary Full Adder is a graphical representation of 4 daisy chained full adders.
The idea is to use the dashboard as an educational tool for the curious.
The user selects two 4-bit integers to sum using two sets four toggle switches.
When no user input is detected for ~20 seconds, the dashboard periodically selects two random integers to sum thus displaying a retro computer vibe of dancing lights.
The discrete combinational logic illuminated graphic reflects the two 4-bit inputs.
The legend displays the truth table for the AND, OR, and XOR gates; and decodes binary to decimal.
Behind the scenes is microcontroller, two led drivers, 109 red LEDs, and a mess of wires.
The dashboard is driven by and Arduino Nano and two I2C PCA9685 16x PWM drivers.
The 109 LEDs are held in place using several 3D printed brackets.
Everything is wired together using silicon sheathed 30AWG wire.
Source code and design files: https://github.com/reubenstr/4-BitAdder
The 3D printed LED holders worked rather well during assembly and to keep the LEDs flush with the acrylic front panel. In retrospect, if creating more than one dashboard the time investment for creating multiple PCBs would outweigh the time and frustration of manually wiring 109 LEDs (and resistors).
Although the goal with this projects was to keep the functionality and aesthetic as simple as possible, a variation with a variety of input and output methods could enhance the educational aspect. Example: 7-segment displays, keypads, etc.