Traffic Signal

| August 2021 |

This is a 31.5" tall Arduino powered programmable traffic signal with a trapezoidal shape, 10.5" at the front and 6" at the back, like a real-world traffic signal. The lenses are 10" glass lens from San Francisco that are no longer in use.

Construction

The entire structure was CNC'ed from a salvaged piece of 3/4" plywood that had a severe bow that had to be flattened with weights and a water soak. However, this caused significant cracking on the outer veneer that had to be filled with wood filler and primer. Hinged front and back panels on the traffic signal are secured using a ball catch latch and provide access to the internal electronics. The hinges and latches were adhered using epoxy, and the exterior was primed, and spray painted black. There are two-disc cutouts, one on top and one on bottom, each with a lazy Susan mounted underneath that allow the traffic signal to rotate freely when top or bottom mounted.

Electronics

An Arduino Uno powers a LCD menu that allows the user to program the traffic signal. There are 4 menu options: All On, Flashing RYG, Flashing Red, Flashing Yellow, and Random RYG. A potentiometer is used to scroll through the menu and the 3 vertical buttons are used to increase, confirm, and decrease the time for each respective light. A relay controls each LED bulb that is wired to AC power. A 120v 3D printed outlet box was installed on the inside, powers the Arduino, and turns each bulb on/off based on the selected programming. There is also an on/off toggle switch to turn all the lights on/off but keeps the Arduino running so any custom settings are saved. The electronics were mounted to a custom laser cut 1/8" clear acrylic piece with heat shrink tubing added where necessary.