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Arduino Essentials

You're reading from   Arduino Essentials Enter the world of Arduino and its peripherals and start creating interesting projects

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Product type Paperback
Published in Feb 2015
Publisher Packt
ISBN-13 9781784398569
Length 206 pages
Edition 1st Edition
Tools
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Toc

Table of Contents (12) Chapters Close

Preface 1. Meeting the Arduino Family 2. The Arduino Development Environment FREE CHAPTER 3. Interacting with the Environment the Digital Way 4. Controlling Outputs Softly with Analog Outputs 5. Sensing the Real World through Digital Inputs 6. Analog Inputs to Feel Between All and Nothing 7. Managing the Time Domain 8. Communicating with Others 9. Dealing with Interrupts 10. Arduino in a Real Case – Greenhouse Control Index

Other types of digital sensors


Switches are perhaps the most used devices as digital input sensors but obviously not the only ones. Any device that can open or close a circuit branch can be easily configured and connected to Arduino to act like a digital input sensor, from a reed relay (http://en.wikipedia.org/wiki/Reed_relay) to a PIR motion detector (http://en.wikipedia.org/wiki/Passive_infrared_sensor).

One of those devices that are very cheap and easy to acquire are optocouplers or, as they are sometimes referred to, optical switches.

An optocoupler is a very simple device that has two parts:

  • An infrared light emitter: This is a simple infrared LED in a housing that directs its light emission in a precise direction

  • A phototransistor: This is a special kind of transistor whose base is activated by the reception of light, infrared light in this case, and also in a special case that ensures that the phototransistor gets excited only with light coming from a concrete direction—that of the...

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