Book Image

Practical Python Programming for IoT

By : Gary Smart
Book Image

Practical Python Programming for IoT

By: Gary Smart

Overview of this book

The age of connected devices is here, be it fitness bands or smart homes. It's now more important than ever to understand how hardware components interact with the internet to collect and analyze user data. The Internet of Things (IoT), combined with the popular open source language Python, can be used to build powerful and intelligent IoT systems with intuitive interfaces. This book consists of three parts, with the first focusing on the "Internet" component of IoT. You'll get to grips with end-to-end IoT app development to control an LED over the internet, before learning how to build RESTful APIs, WebSocket APIs, and MQTT services in Python. The second part delves into the fundamentals behind electronics and GPIO interfacing. As you progress to the last part, you'll focus on the "Things" aspect of IoT, where you will learn how to connect and control a range of electronic sensors and actuators using Python. You'll also explore a variety of topics, such as motor control, ultrasonic sensors, and temperature measurement. Finally, you'll get up to speed with advanced IoT programming techniques in Python, integrate with IoT visualization and automation platforms, and build a comprehensive IoT project. By the end of this book, you'll be well-versed with IoT development and have the knowledge you need to build sophisticated IoT systems using Python.
Table of Contents (20 chapters)
1
Section 1: Programming with Python and the Raspberry Pi
6
Section 2: Practical Electronics for Interacting with the Physical World
9
Section 3: IoT Playground - Practical Examples to Interact with the Physical World

Digital input

Generally, when we think about digital input and voltages for a 3.3-volt device such as the Raspberry Pi, we think of connecting a pin to the ground (0 volts) to drive it low or connect it to 3.3 volts to make it high. In most applications, this is exactly what we will strive to do. However, in truth, there is more to this story because GPIO pins don't just operate at two discrete voltage levels. Instead, they work within a range of voltages that define an input pin as being high and low. This applies to the Raspberry Pi and similar computers with GPIOs, microcontrollers, ICs, and breakout boards.

Consider the following diagram, which shows a voltage continuum between 0 and 3.3 volts, as well as three highlighted areas labeled low, floating, and high:

Figure 6.4 – Digital input trigger voltages

This illustration is telling us that if we apply a voltage between 2.0 volts and 3.3 volts, then the input pin will read as a digital high. Alternatively...