Book Image

Hands-On Mobile and Embedded Development with Qt 5

By : Lorn Potter
Book Image

Hands-On Mobile and Embedded Development with Qt 5

By: Lorn Potter

Overview of this book

Qt is a world-class framework, helping you to develop rich graphical user interfaces (GUIs) and multi-platform applications that run on all major desktop platforms and most mobile or embedded platforms. The framework helps you connect the dots across platforms and between online and physical experience. This book will help you leverage the fully-featured Qt framework and its modular cross-platform library classes and intuitive APIs to develop applications for mobile, IoT, and industrial embedded systems. Considerations such as screen size, device orientation changes, and small memory will be discussed. We will focus on various core aspects of embedded and mobile systems, such as connectivity, networking, and sensors; there is no IoT without sensors. You will learn how to quickly design a flexible, fast, and responsive UI that looks great. Going further, you will implement different elements in a matter of minutes and synchronize the UI elements with the 3D assets with high precision. You will learn how to create high-performance embedded systems with 3D/2D user interfaces, and deploy and test on your target hardware. The book will explore several new features, including Qt for WebAssembly. At the end of this book, you will learn about creating a full software stack for embedded Linux systems using Yocto and Boot to Qt for Device Creation.
Table of Contents (23 chapters)
Title Page
Dedication
About Packt
Foreword
Contributors
Preface
Index

What is Bluetooth Low Energy?


Bluetooth Low Energy (BLE), or Bluetooth Smart as it is also called, was originally developed by Nokia under the name Wibree and was originally released in 2006. It was integrated into the Bluetooth 4.0 specification and released in 2010.

Bluetooth is a wireless connection technology that operates in the 2,400-2,483.5 MHz range of the 2.4 GHz frequency band. There are 79 data channels it can choose for transmitting packets. BLE limits the data channels to 40.

BLE is targeted at mobile and embedded devices that require lower power consumption. Unlike Bluetooth, BLE is designed for devices that exchange small amounts of data periodically, as opposed to regular Bluetooth that was designed for continuous data streams. Most importantly, BLE has a sleep mode that it uses to conserve power.

Qt has support for BLE in the Qt Connectivity module alongside Near-field Communication (NFC). BLE has a number of profiles and services:

  • Alerts
  • Battery
  • Fitness
  • Health
  • HID
  • Internet
  • Mesh
  • Sensors...