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)

Playing the app

Now, your Raspberry Pi is successfully connected with the Blynk cloud at The following steps show you how to use the app to control the LED attached to GPIO pin 18:

  1. Tap the Play button on the toolbar:
Tapping Play button on the toolbar
  1. This will switch you from edit mode to play mode, where you can interact with the hardware. The play button is replaced with a Stop button that allows you to go back to edit mode:
Application in play mode
  1. You can tap the chip icon (the icon like a microprocessor) to see the device status, whether it is online or offline. The following screenshot show that the Raspberry Pi is online:
Checking device status: Raspberry Pi is online
  1. If your Raspberry Pi is offline, the notification looks as shown in the following screenshot. There are several reasons it can go offline. Some of them are:
    • Lost internet...