Book Image

Raspberry Pi Zero Cookbook

Book Image

Raspberry Pi Zero Cookbook

Overview of this book

The Raspberry Pi Zero, one of the most inexpensive, fully-functional computers available, is a powerful and revolutionary product developed by the Raspberry Pi Foundation. The Raspberry Pi Zero opens up a new world for the makers out there. This book will give you expertise with the Raspberry Pi Zero, providing all the necessary recipes that will get you up and running. In this book, you will learn how to prepare your own circuits rather than buying the expensive add–ons available in the market. We start by showing you how to set up and manage the Pi Zero and then move on to configuring the hardware, running it with Linux, and programming it with Python scripts. Later, we integrate the Raspberry Pi Zero with sensors, motors, and other hardware. You will also get hands-on with interesting projects in media centers, IoT, and more.
Table of Contents (17 chapters)
Raspberry Pi Zero Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

Converting a 5V signal into a 3.3V signal and slew rates


Note

Microcontrollers such as Arduinos have become extremely popular over the years and are great to have if getting involved in the Internet of Things. It would be completely natural to have an Arduino collecting measurements and sending that data to a Raspberry Pi for processing. A big issue between the two, however, is what they understand the HIGH signal to be. For a Raspberry Pi, the HIGH signal is 3.3V. For an Arduino, HIGH is 5V. Before your data is sent from a 5V high system to a 3.3V HIGH system, you need to convert it. That's what we will cover in this recipe. Technically the Raspberry PI will interpret any voltage under 0.8V as LOW and any voltage above 1.3V as HIGH. In between, depends on the input logic.

When unconnected, CMOS inputs will oscillate rapidly and may draw a dangerous amount of power. This is why the RPi has weak 50KΩ pull up resistors enabled by default on all GPIOs on startup. Inputs can also be configured...