Skip to Main Content
Raspberry Pi Cookbook, 2nd Edition
book

Raspberry Pi Cookbook, 2nd Edition

by Simon Monk
June 2016
Beginner to intermediate content levelBeginner to intermediate
508 pages
9h 40m
English
O'Reilly Media, Inc.
Content preview from Raspberry Pi Cookbook, 2nd Edition

Chapter 13. Sensors

13.0 Introduction

In this chapter, you will look at recipes for using sensors of various types that will allow the Raspberry Pi to measure temperature, light, and more.

Compared to a board like the Arduino, the Raspberry Pi lacks analog inputs. This means that for many sensors, it is necessary to use additional analog-to-digital (ADC) converter hardware. Fortunately, this is relatively easy to do. It is also possible to use resistive sensors with a capacitor and a couple of resistors.

Most of the recipes will require the use of a solderless breadboard and male-to-female jumper wires (see Recipe 9.8).

13.1 Using Resistive Sensors

Note

Be sure to check out the accompanying video for this recipe at http://razzpisampler.oreilly.com.

Problem

You want to connect a variable resistor to a Raspberry Pi and measure its resistance so that you can use the position of the variable resistor’s knob in your Python program.

Solution

You can measure resistance on a Raspberry Pi using nothing more than a capacitor, a couple of resistors, and two GPIO pins. In this case, you will be able to estimate the position of the knob on a small variable resistor (trimpot) by measuring its resistance from its slider contact to one end of the pot.

To make this recipe, you will need:

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Raspberry Pi Cookbook, 3rd Edition

Raspberry Pi Cookbook, 3rd Edition

Simon Monk

Publisher Resources

ISBN: 9781491939093Errata Page