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.
Components:
- 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
The Arduino code:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 | //Constants #define REDPIN 9 #define YELLOWPIN 10 #define GREENPIN 11 #define BUZZ 12 //Variables int ledDelay=50; long previousMillisLights = 0; long intervalLights = 500; long previousMillisTemperature = 0; long intervalTemperature = 1000; void setup() { Serial.begin(9600); pinMode(REDPIN, OUTPUT); pinMode(YELLOWPIN, OUTPUT); pinMode(GREENPIN, OUTPUT); pinMode(BUZZ, OUTPUT); } void loop() { unsigned long currentMillis = millis(); if ((unsigned long)(currentMillis - previousMillisLights) >= intervalLights) { redPoliceLights(); yellowPoliceLights(); greenPoliceLights(); //add here the code if you want the turn on the buzzer //analogWrite(BUZZ, HIGH); intervalLights = currentMillis; } } //turn ON and OFF the red light void redPoliceLights(){ analogWrite(REDPIN, HIGH); delay(ledDelay); analogWrite(REDPIN, LOW); delay(ledDelay); analogWrite(REDPIN, HIGH); delay(ledDelay); analogWrite(REDPIN, LOW); delay(ledDelay); analogWrite(REDPIN, HIGH); delay(ledDelay); analogWrite(REDPIN, LOW); delay(ledDelay); } //turn ON and OFF the yellow light void yellowPoliceLights(){ analogWrite(YELLOWPIN, HIGH); delay(ledDelay); analogWrite(YELLOWPIN, LOW); delay(ledDelay); analogWrite(YELLOWPIN, HIGH); delay(ledDelay); analogWrite(YELLOWPIN, LOW); delay(ledDelay); analogWrite(YELLOWPIN, HIGH); delay(ledDelay); analogWrite(YELLOWPIN, LOW); delay(ledDelay); } //turn ON and OFF the green light void greenPoliceLights(){ analogWrite(GREENPIN, HIGH); delay(ledDelay); analogWrite(GREENPIN, LOW); delay(ledDelay); analogWrite(GREENPIN, HIGH); delay(ledDelay); analogWrite(GREENPIN, LOW); delay(ledDelay); analogWrite(GREENPIN, HIGH); delay(ledDelay); analogWrite(GREENPIN, LOW); delay(ledDelay); } |
Tower Light Demo:
That’s a cool project!
I want to use one of those tower light in one of my project as well. Do you think that it’s visible which light is turned on when it is placed in direct sunlight?