I made a police light application with a tower light and Arduino

A few days ago I bought a three-color tower light with buzzer for visual and audible alerts. And because I’m a big kid, I thought to build as the first application a game of lights in the style of a police car. The result will be seen at the bottom of this article.

Before entering into the connection and programming area, I give you some details about the product. The tower light has three colors and a buzzer. The tower can be easily controlled by an Arduino board, four N-channel MOSFETs or NPN transistors, and four resistors.

The light tower is branded Adafruit and produced in China. At least this is written on the product that I use in this tutorial. Also, there is a schema somewhere on it with Chinese letters. Thank you Adafruit!

Everywhere I’ve been looking for information about how it works and how I can control it, I’ve given this tutorial. The tutorial is dedicated to the RGB LED strips and less to a light tower. Generally, Adafruit produces good tutorials, so I think that I don’t have to make a great effort to turn ON the lights. But this time I was a bit misguided by the schema with connections found in the tutorial. For the NPN Bipolar Transistors (PN2222), I recommend you carefully look how the three pins of the transistor are located or use the schema from this article. When I connected the light tower just like in the Adafruit’s tutorial (the NPN schema), the result was a tower light that just makes some noise and has two lights on. Obviously, the pins of the transistors were wrongly connected.

Let’s get to the practical side.


  • 1 X Tower Light – Red Yellow Green Alert Light & Buzzer (I buy it from here, but you can buy it also from Amazon)
  • 4 X NPN Bipolar Transistors (PN2222) (link on Amazon)
  • 4 X 100-220 Ohm resistors (link on Amazon)
  • 1 X Arduino board (I think you already have one, but in case I’m wrong, you can take one from here)
  • some wires (link on Amazon)

The schema:

Tower light and Arduino Schema

Tower light and Arduino Schema

The Arduino code:

Tower Light Demo:

  • Posted in: Tutorials

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