Chapter 9 Invisible Ruler


  • 1 Arduino
  • 1 Arduino USB cable
  • 1 breadboard
  • 3 jumper cables
  • Your computer

Special parts

  • 1 Ping sensor

Optional parts

  • 1 LED

Maybe you know how bats “see” with sound: emitting high-pitched clicks and listening for how those sounds bounce off things. It’s called “echolocation” because the bats literally locate things using echoes. We can make an Arduino do the same thing!

Concepts: Distance Sensing

Detecting objects around us is key to navigating our world, and can be important for smart objects, too. Is the cat nearby? Am I about to bump into a wall?

To give our Arduino “eyes,” we’ll use a Ping sensor, which, just like a bat, emits high-pitched sounds and listens for them to return. By timing how ...

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