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

Determining the darkness level with analog inputs and the mraa library


We will create a new DarknessSensor class to represent the photoresistor included in the voltage divider and connected to our board, specifically, to an analog input pin. As we already wrote code to read and transform an analog input, we will use the previously created VoltageInput class. The following lines show the code for the new DarknessSensor class that works with the mraa library. The code file for the sample is iot_python_chapter_06_02.py.

import mraa
import time

class DarknessSensor:
    # Light level descriptions
    light_extremely_dark = "extremely dark"
    light_very_dark = "very dark"
    light_dark = "just dark"
    light_no_need_for_a_flashlight = \
        "there is no need for a flashlight"
    # Maximum voltages that determine the light level
    extremely_dark_max_voltage = 2.0
    very_dark_max_voltage = 3.0
    dark_max_voltage = 4.0

    def __init__(self, analog_pin):
        self.voltage_input...