Book Image

Hands-On Internet of Things with Blynk

By : Pradeeka Seneviratne
Book Image

Hands-On Internet of Things with Blynk

By: Pradeeka Seneviratne

Overview of this book

Blynk, known as the most user-friendly IoT platform, provides a way to build mobile applications in minutes. With the Blynk drag-n-drop mobile app builder, anyone can build amazing IoT applications with minimal resources and effort, on hardware ranging from prototyping platforms such as Arduino and Raspberry Pi 3 to industrial-grade ESP8266, Intel, Sierra Wireless, Particle, Texas Instruments, and a few others. This book uses Raspberry Pi as the main hardware platform and C/C++ to write sketches to build projects. The first part of this book shows how to set up a development environment with various hardware combinations and required software. Then you will build your first IoT application with Blynk using various hardware combinations and connectivity types such as Ethernet and Wi-Fi. Then you'll use and configure various widgets (control, display, notification, interface, time input, and some advanced widgets) with Blynk App Builder to build applications. Towards the end, you will learn how to connect with and use built-in sensors on Android and iOS mobile devices. Finally you will learn how to build a robot that can be controlled with a Blynk app through the Blynk cloud and personal server. By the end of this book, you will have hands-on experience building IoT applications using Blynk.
Table of Contents (10 chapters)


The LED widget simulates an LED and it can be used as an indicator to present the status or amount of an input. As an example, you can use it to present the status of a switch or output value of a potentiometer attached to the Raspberry Pi.

You can add an LED widget onto your Blynk app with the Widget Box by tapping LED under DISPLAYS. The LED widget costs 100 units of energy (see the following screenshot):

LED widget listed under DISPLAYS

Using virtual pins

The LED widget supports only virtual pins. Using a momentary push button with Raspberry Pi is a great way to learn how virtual pins work with inputs. In this example, you will see how the LED widget can be turned on and off according to the status of the momentary...