Book Image

Developing IoT Projects with ESP32

By : Vedat Ozan Oner
Book Image

Developing IoT Projects with ESP32

By: Vedat Ozan Oner

Overview of this book

Developing IoT Projects with ESP32 provides end-to-end coverage of secure data communication techniques from sensors to cloud platforms that will help you to develop production-grade IoT solutions by using the ESP32 SoC. You'll learn how to employ ESP32 in your IoT projects by interfacing with different sensors and actuators using different types of serial protocols. This book will show you how some projects require immediate output for end-users, and cover different display technologies as well as examples of driving different types of displays. The book features a dedicated chapter on cybersecurity packed with hands-on examples. As you progress, you'll get to grips with BLE technologies and BLE mesh networking and work on a complete smart home project where all nodes communicate over a BLE mesh. Later chapters will show you how IoT requires cloud connectivity most of the time and remote access to smart devices. You'll also see how cloud platforms and third-party integrations enable endless possibilities for your end-users, such as insights with big data analytics and predictive maintenance to minimize costs. By the end of this book, you'll have developed the skills you need to start using ESP32 in your next wireless IoT project and meet the project's requirements by building effective, efficient, and secure solutions.
Table of Contents (18 chapters)
1
Section 1: Using ESP32
7
Section 2: Local Network Communication
12
Section 3: Cloud Communication

Adding a speaker with I²S

Inter-IC Sound (I²S) is another type of data interface but for audio. Essentially, it has three lines for the following:

  • Data, Data-In (DIN), or Data-Out (DOUT)
  • Clock or bit clock (BCLK)
  • Channel select, word select (WS), or left-right clock (LRCLK)

The interface is a standard; however, the naming is not, as we see above. The data line carries stereo audio data for both the left (channel 0) and right (channel 1) channels. The channel select signal indicates which channel data is currently being transferred: it is a low level for the left channel and a high level for the right channel. Finally, the clock line is a common clock for both ends provided by the master, which is usually the sending party in this type of communication.

ESP32 provides two I2S peripherals that can be configured as input or output. When configured as input, a mic can be used to sample the sound data and store it on the flash for later use. If it is...