Wireless sensor networks (WSNs) consist of small, low-powered devices equipped with sensors, microcontrollers, and wireless communication capabilities. They consist of tiny sensor nodes that can communicate with each other and exchange data. These devices are usually deployed in large numbers to monitor a myriad of physical or environmental conditions, such as humidity, air, and sound. Once information has been obtained from the environment, the nodes then send it to a base station, which in turn sends the data to a wired network or performs an action, depending on the thresholds that have been set.
These networks use air as their transmission medium as part of wireless transmission. Compared to traditional wired sensor networks, they offer many benefits, such as cost-effectiveness and flexibility in deployment. Furthermore, they can nearly replicate the performance of wired networks, particularly with standards such as IEEE 802.11. Despite this, they have several key challenges, such as limited power, interference, and scalability. With emerging technologies such as advances in semiconductor technology, which allows for more chip capabilities, which, in turn, adds to processor capabilities, we will continue to see WSNs be formed as part of many users’ IoT solutions.
In this chapter, we’re going to cover the following main topics:
Understanding the architecture, application, and challenges within WSNs
Building APIs for WSNs
Architecting IoT networks based on WSNs
Technical requirements
This chapter will require you to have the following hardware installed:
ESP32-CAM
Single channel relay
1 1k ohm resistor
Push button switch
Jumper cables
Breadboard
Mobile charger 5V/1A to use as a power supply
iPhone/Android phone (to run the Blynk app)
Here’s the list of software you’ll need for this chapter:
Blynk app
Arduino IDE
The Blynk app
Blynk is a platform that allows users to build graphical user interfaces (GUIs) with ease, which allows them to monitor and control IoT devices. It provides a wide number of widgets, such as buttons, sliders, or gauges, that can be added to the GUI and have specific actions linked to them or data points on the device. It can be downloaded as an app on iOS or Android and can serve as a bridge between the GUI and the device, allowing users to remotely control and monitor the device from the convenience of their smartphone or tablet.
We will be using Blynk for our smart energy monitoring and management system practical scenario later. The steps for using it, along with how we will be building on it, will be discussed later in the practical section.
You can find the GitHub folder that contains the code for this chapter at https://github.com/PacktPublishing/IoT-Made-Easy-for-Beginners/tree/main/Chapter05/.
