Chapter 3 A Dark-Detecting Light


  • 1 Arduino Uno
  • 1 Arduino USB cable
  • 1 breadboard
  • Your computer
  • 1 LED
  • 3 jumper wires
  • 1 photoresistor (some kits call these a “photocell”)
  • 1 10K-ohm (10KΩ) resistor, which has a brown-black-orange stripe pattern

Let’s make our objects just a little smarter by adding the ability to notice changes in the immediate area with a sensor. In this case, we’ll make our blinky bulb respond to the amount of light the sensor “sees.”

Along the way, you’ll learn how easy it is to detect light levels, and about the breadboard—a piece of plastic used to connect electronic parts together without soldering.

Concept: Sensing Light

Light sensors are among the simplest sensors around, and they’re super cheap, too. ...

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