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1) Overview

In this lesson, we’ll learn how remote to control a relay switch to turn on/off a led. Actually the code is quite similar to that of Lesson 2. The only difference is that we use Relay to turn on/off the LED.
Relay is switch which is turn on/off a high voltage circuit with low voltage signal. We often use relay to control 110V or 220 V devices in home and office.

2 )Hardware Preparation

OSOYOO Basic board 1
Ethernet Shield W5100 1
USB cable 1
1K resistor 1
Relay 1
Jumper wires several
Breadboard 1

3) Hardware connection

Connect the relay with OSOYOO Basic board as following diagram:

4)Software Installation

Download the sketch file from :

Unzip the download file and enter the folder W5100-lesson2, double click the w5100-lesson12.ino file, upload the sketch to your IDE . Open your Serial Monitor, you can see your router will assign an IP address to your IDE as following:

In above example, is the IP address of my mainboard .
Now use another computer or your cell phone’s  browser to visit url :
Your browser will show following result:

5)Make a Test:

Click Turn On LED link, your LED will be turn on , then click Turn Off LED link, your LED will be turn off.