Chapter 1: Getting Started with ESP32
Espressif ESP32 is a powerful tool in the toolbox of a developer for many types of Internet of Things (IoT) projects. We are all developers, and we all know how important it is to select the right tool for a given problem in a domain. To solve the problem, we need to understand the domain, and we need to know the available tools and their features that are important for that specific problem in order to find the right one (or perhaps several combined). After selecting the tool, we eventually need to figure out how to use it in the most efficient and effective way possible so as to maximize the added value for end users.
In this chapter, I will discuss the technology, IoT, in general, what an IoT solution looks like in terms of basic architecture, and how ESP32 fits into those solutions as a tool. If you are new to IoT technology, or are thinking of using ESP32 in your next project, this chapter helps you to understand the big picture from the technology perspective by describing what ESP32 provides, its capabilities, and its limitations.
The main topics covered in this chapter are as follows:
- IoT as an emerging technology and its application areas with some examples
- The basic structure of IoT solutions, including security considerations
- An introduction to the ESP32 platform and modules
- Available development platforms and frameworks
- Real-Time Operating System (RTOS) options for ESP32
Technical requirements
In this book, we are going to have many practical examples where we can learn how to use ESP32 effectively in real-world scenarios. Although links to the examples are provided within each chapter, you can take a sneak peek at the online repository here: https://github.com/PacktPublishing/Internet-of-Things-with-ESP32. The examples are placed in their relative directories of the chapters for easy browsing. There is also a common source code directory that contains the shared libraries across the chapters.
We will use different software tools and hardware components throughout the book. Each chapter shows its own list of these tools and components.
IoT as an emerging technology
When I started my career 20 years ago, my first project involved collecting data regarding radio and TV stations by measuring some Radio Frequency (RF) parameters of broadcasted channels. The task was to design and develop a system in order to understand whether the stations comply with the existing regulations in the country. As a solution for this engineering problem, the technical leaders in the team designed a van with various equipment, including the following:
- A spectrum analyzer
- A TV demodulator
- Different types of antennas to measure those parameters
- An industrial PC to run the application software
- A radio transmitter to upload the measurements and some basic analysis to a data center
I was lucky that I participated in such a project in my very first job and saw how a complete data acquisition system was designed and developed to solve a real-world problem. This project was in the year just after Kevin Ashton introduced the term Internet of Things to technology literature in 1999.
When I first heard this term and was trying to understand what it actually means, I quickly noticed the similarities between an IoT solution and our monitoring van. We collected data from the environment by using some sensing devices, we had a processing unit, and we also transferred information to a central data storage and processing center. This last part was to access more processing and spot correlation between data coming from multiple vans. So, why not call it an IoT product? Well, not exactly. From that perspective, you could easily call any SCADA or PLC product an IoT system as well, so IoT would only then constitute a rebranding of existing technologies.
What is IoT?
Although the definition of IoT might change slightly from different viewpoints, there are some key concepts in the IoT world that differentiate it from other types of technologies:
- Connectivity: An IoT device is connected, either to the internet or to a local network. An old-style thermostat on the wall waiting for manual operation with basic programming features doesn't count as an IoT device.
- Identification: An IoT device is uniquely identified in the network so that data has a context identified by that device. In addition, the device itself is available for remote update, remote management, and diagnostics.
- Autonomous operation: IoT systems are designed for minimal or no human intervention. Each device collects data from the environment where it is installed, and it can then communicate the data with other devices to detect the current status of the system and respond as configured. This response can be in the form of an action, a log, or an alert if required.
- Interoperability: Devices in an IoT solution talk to one another, but they don't necessarily belong to a single vendor. When devices designed by different vendors share a common application-level protocol, adding a new device to that heterogeneous network is as easy as clicking on a few buttons on the device or on the management software.
- Scalability: IoT systems are capable of horizontal scalability to respond to an increasing workload. A new device is added when necessary to increase capacity instead of replacing the existing one with a superior device (vertical scalability).
- Security: I wish I could say that every IoT solution implements at least the minimal set of mandatory security measures, but unfortunately, this is not the case, despite a number of bad experiences, including the infamous Mirai botnet attack. On a positive note, I can say that IoT devices mostly have secure boot, secure update, and secure communication features to ensure confidentiality, integrity, and availability the (CIA triad).
Gartner added IoT in the 2011 hype cycle, with the expectation of more than 10 years to mainstream adoption. However, many related technologies, such as RFID, mesh networking, and Bluetooth, were already on the list many years before 2011, along with enablers such as mobile and cloud technologies. Since then, Gartner has added several other IoT technologies and applications to its list, including the following:
- IoT platform
- Connected home
- Smart dust
- Edge computing
- Low-cost, single-board computers at the edge
5G and embedded AI are other revolutionary technologies on the Gartner list that support IoT and expand its area of application.
Where do we apply IoT?
The application areas are vast, but conceptually speaking, we can group them into two basic categories:
- In the consumer IoT category, we can see mainly smart home and security systems, personal healthcare products, wearable technologies, and asset tracking applications.
- The industrial IoT category has more application areas, as you might expect. Every year, IoT Analytics publishes a top-10 trend list for industrial applications by reviewing thousands of new projects and the 2020 list contains manufacturing, transportation, energy, retail, cities, healthcare, supply chain, agriculture, and building applications in that order (https://iot-analytics.com/top-10-iot-applications-in-2020).
Since we have limited space in this book, I don't want to waste pages talking about each of these application areas. Instead, I'd like to share more interesting cases to show how the IoT technology can provide powerful solutions when incorporated with other cutting-edge technologies.
AI/ML on the edge
AI has been around for a long time and there are many successful examples...
