Microduino ENC Network (7)

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Objective

This tutorial will show you how to control a LED from a web page.

Equipment

  • Other equipment
    • USB cable

A bit of HTML

First, you need to write an HTML page that will be the web interface Arduino sends to your web browser:

Htmlcode.jpg

This web page is very simple: a label about LED’s actual status and a button to change it.

Looking at page's HTML source, you can identify the variable elements; i.e. the elements that change according to the LED's status:

From the source, you can also understand what's going to happen when the user clicks the button: his browser will ask to Arduino a web page named:

/?status=ON, if the LED has to be turned on /?status=OFF, if the LED has to be turned off The use of ?name=value to send data to a web server reflects the standard syntax of HTML forms using the GET method.

Schematic

  • Microduino-ENC28J60
  • Microduino-RJ45
  • Microduino-Core
  • Microduino-FT232R

Stack all modules and then connect the ethernet cable, as follows:

MicroduinoENCLED.jpg

Program

Refer to ENCnetworkseven

Debug

Step 1: Download the EtherCard library and copy to your libraries fold of IDE, then restart IDE. https://github.com/jcw/ethercard

Step 2: Explain the program:

//Two static strings (ON, OFF) and two variables are defined: the variables will be used in HTML page creation, associating to them one of the two static strings.

   char* on = "ON";
   char* off = "OFF";
   char* statusLabel;

  char* buttonLabel;

//In the setup(), in addition to EtherCard library setup, LED's initial status (off) is configured.

     pinMode(ledPin, OUTPUT);
     digitalWrite(ledPin, LOW);
     ledStatus = false;

//In the main loop(), our sketch parse browser's request (saved in Ethernet::buffer buffer starting from pos position) looking for status ON/OFF commands.

       if(strstr((char *)Ethernet::buffer + pos, "GET /?status=ON") != 0) {
         Serial.println("Received ON command");
         ledStatus = true;
       }
       if(strstr((char *)Ethernet::buffer + pos, "GET /?status=OFF") != 0) {
         Serial.println("Received OFF command");
         ledStatus = false;
       }

//The status of ledPin (Arduino's PIN the LED is connected to) is updated and the two string variables are associated to the correct labels:

       if(ledStatus) {
         digitalWrite(ledPin, HIGH);
         statusLabel = on;
         buttonLabel = off;
       } else {
         digitalWrite(ledPin, LOW);
         statusLabel = off;
         buttonLabel = on;
       }

Step 3: Connect the bulb, as follows:

ConnectLED.jpg

Step 4: Compile the code and download it.

Step 5: Use the browser to access the Microduino's IP, then click ON/OFF, observe the bulb's state.

Result

Access Microduino's IP, you will see following picture:

LEDWebPage.jpg

Then you can use the browser to control the bulb.

Video

http://v.youku.com/v_show/id_XNzAzMzM0NzUy.html