The streetlight is a classic exercise project in learning microcontrollers. In its basic form, it is formed with some wires, 3 LEDs and matching current limiting resistors and build unto a breadboard or PCB. While it may not be difficult to build, the time and resources spend may sometimes be enough reason to look for off the shelves solutions.
The 3-LED module aka the “Streetlight Module” is basically 3 Ledswith the necessary resistors and a common ground pin (CC) built into a small PCB with the 3 signals and CC pin broken out into 4 standard pitched right-angled headers. This makes it easy to connect to an existing circuit or an Arduino and also allows connection in a breadboard. It may also be used as simple notification module.