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)

Value Display

The Value Display widget can be used to display incoming data from the sensors attached to the Raspberry Pi. You can use one of the following mechanisms to display data on the Value Display widget:

  • Perform requests by the widget: The widget in the app reads a pin with a certain frequency. This is also called a pull model
  • Pushing data from the hardware: Send data from the hardware to the app widget at intervals. This is also called a push model

You can add a Value Display widget onto your Blynk app with the Widget Box by tapping Value Display under DISPLAY. The Value Display widget costs 200 units of energy.

The default label is VALUE, as shown in the following screenshot:

Value Display widget added to the canvas

Using digital pins