Creating our night-light

Now that we know our light sensor works, we can add an LED and create our night-light.

Wiring up the LED

Connect the short leg of your LED to a ground rail using a 330K ohm resistor, and wire the long leg to GPIO #5, also known as P1-29:

Coding this project

Create a file in the same folder as the other files from this chapter, and copy the contents of print-light-sensor-readings.js into it.

In the start of the board.on('ready') handler, add a constructor for our LED:

let light = new five.Led('P1-29')

And in the lightSensor.on('change') function, replace the console.log statement with the logic that will turn the LED on and off:

if(this.value <= 25) {
  light.on()
} else {
  light.off()
}

And we're ready to run! Load the folder onto your Pi, navigate to the folder in your Pi's SSH session, and run:

sudo node night-light.js

When you cover the light sensor with your thumb, the LED should light up, as shown in the following image:

 

 And when you remove your thumb (in a well-lit...