Book Image

Creative DIY Microcontroller Projects with TinyGo and WebAssembly

By : Tobias Theel
Book Image

Creative DIY Microcontroller Projects with TinyGo and WebAssembly

By: Tobias Theel

Overview of this book

While often considered a fast and compact programming language, Go usually creates large executables that are difficult to run on low-memory or low-powered devices such as microcontrollers or IoT. TinyGo is a new compiler that allows developers to compile their programs for such low-powered devices. As TinyGo supports all the standard features of the Go programming language, you won't have to tweak the code to fit on the microcontroller. This book is a hands-on guide packed full of interesting DIY projects that will show you how to build embedded applications. You will learn how to program sensors and work with microcontrollers such as Arduino UNO and Arduino Nano IoT 33. The chapters that follow will show you how to develop multiple real-world embedded projects using a variety of popular devices such as LEDs, 7-segment displays, and timers. Next, you will progress to build interactive prototypes such as a traffic lights system, touchless hand wash timer, and more. As you advance, you'll create an IoT prototype of a weather alert system and display those alerts on the TinyGo WASM dashboard. Finally, you will build a home automation project that displays stats on the TinyGo WASM dashboard. By the end of this microcontroller book, you will be equipped with the skills you need to build real-world embedded projects using the power of TinyGo.
Table of Contents (13 chapters)

Learning to measure distances

If you have ever wondered how touchless soap dispensers or touchless blow dryers register that there is a hand beneath them, there is a good chance that they are using the HC-SR04 ultrasonic sensor. We are going to use this sensor to measure the distance between an object and the sensor. Let's begin with the HC-SR04 sensor.

Understanding the HC-SR04 sensor

The HC-SR04 sensor emits an ultrasound at 40k Hz, which travels through the air and bounces back if the emitted pulse collides with any object in its path. The sensor cannot be used as a detector for other ultrasound pulses, as it only registers echoes from the exact same pulse that it itself emitted. Typically, these sensors look similar to the one in the following photograph:

Figure 5.2 – The HC-SR04 sensor

This sensor has the following technical specifications:

  • It has a detection range from 2 to 400 centimeters.
  • It draws less than 2 mA current...