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)

Notification widget

The Notification widget allows you to send push notifications from your Raspberry Pi to your smartphone or tablet.

This has the following limitations:

  • The maximum message length is 128 characters (mix of alphanumeric and symbols)
  • You can send only one notification per 15 seconds

However, you can increase the message length by including the following statement at the beginning of the code:

#define BLYNK_MAX_SENDBYTES 256 // Default is 128

You can add a Notification widget onto your project canvas using the Widget Box. The Notification widget also consumes 0 units of energy from your energy bank. Only one notification widget is allowed for a project:

Notification widget is added next to the Twitter widget

Configuring the Notification widget