Book Image

Internet of Things with Python

By : Gaston C. Hillar
Book Image

Internet of Things with Python

By: Gaston C. Hillar

Overview of this book

Internet of Things (IoT) is revolutionizing the way devices/things interact with each other. And when you have IoT with Python on your side, you'll be able to build interactive objects and design them. This book lets you stay at the forefront of cutting-edge research on IoT. We'll open up the possibilities using tools that enable you to interact with the world, such as Intel Galileo Gen 2, sensors, and other hardware. You will learn how to read, write, and convert digital values to generate analog output by programming Pulse Width Modulation (PWM) in Python. You will get familiar with the complex communication system included in the board, so you can interact with any shield, actuator, or sensor. Later on, you will not only see how to work with data received from the sensors, but also perform actions by sending them to a specific shield. You'll be able to connect your IoT device to the entire world, by integrating WiFi, Bluetooth, and Internet settings. With everything ready, you will see how to work in real time on your IoT device using the MQTT protocol in python. By the end of the book, you will be able to develop IoT prototypes with Python, libraries, and tools.
Table of Contents (19 chapters)
Internet of Things with Python
Credits
About the Author
Acknowledgments
About the Reviewer
www.PacktPub.com
Preface
Index

Using interrupts to detect pressed pushbuttons


Previously, we analyzed the advantages of disadvantages of reading digital inputs with polling as in the previous examples compared with the usage of interrupts for the same task. If we keep any of the pushbuttons pressed for a long time, the code behaves as if the pushbutton was pressed many times. Now, we don't want this situation to happen, and therefore, we will use interrupts instead of polling to detect when the pushbuttons are pressed.

Before we start editing our code, it is necessary to make changes to our existing wirings. The problem is that not all the GPIO pins support interrupts. In fact, pins number 0 and 1 don't support interrupts and we have our pushbuttons connected to them. In Chapter 1, Understanding and Setting up the Base IoT Hardware when we learned about the I/O pins included in the Intel Galileo Gen 2 board, we understood that the pins labeled with a tilde symbol (~) as a prefix for the number can be used as PWM output...