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 Joystick widget simulates a real joystick with two axes, x and y. You can add a Joystick widget to the canvas by following these steps:

  1. Tap the plus icon to open the Widget Box.
  2. Under Controllers, tap JOYSTICK. A Joystick widget will be added to the canvas.

The Joystick widget consumes 400 power:

Joystick widget

Using digital pins

In split mode, the Joystick widget uses two pins on your hardware for each axis, x and y. The pins should be capable of PWM to write values in a predefined range. Unfortunately, the Raspberry Pi has a single pin that is BCM_GPIO 18 capable with PWM, but you will require one more PWM pin. Therefore, you can't use the Joystick widget with Raspberry Pi digital pins.