I tinkered a while back with using a web server to control and Arduino over a serial connection and then I got an ENC28J60. A really cheap Ethernet socket that can work with the Arduino. It uses the Ethercard community provided library.
My goal was to find a way to turn on and off LEDs which can later become Servos once I've done the hard coding from a web server that then connects to the Arduino over Ethernet.
Using this method the web server and the Arduino don't have to be near each other and even more importantly they don't need to be physically connected.
After a bit of research and trial and error I have something working.
This example presents a simple PHP based web page on the web server with the options to turn on or off 2 LEDs. (sorry for the gaudy colours in the video I thought it would be good to match the LED colours with the menus.
When you click a button on the web page it calls itself with a POST variable set.
The PHP page then interprets this and does an fopen() to the Arduino to do the requested action.
By doing an fopen() the actual connection to the Arduino is not shown on the web page.
The fun with this is that it could be expanded to control more pins easily and also control more than 1 Arduino.
PHP Code on the Server
<!--
Winlkeink
August 2012
For feedback, comments and questions go to winkleink.blogspot.com
This code works with the Ethercard_LED_ONOFF_PHPCall code for Arduino to control Pin2 and Pin4 on
the Arduino using a web server as the interface.
The web page is served with the options and when you click the button it does an fopen in the background
to the Arduino with the relevant command.
By doing this the IP address of the Arduino is not needed and also the commands to control the Arduino is not
shown publicly when compared to using the Arduino as the web server itself and using a GET REQUEST.
By doing it this way you have more control over the Arduino and the web interface.
NOTE:
As always my code is rough and is designed to get things done rather than beign perfect or pretty.
Use as you wish and let me know your thoughts.
-->
<!-- Start of the HTML -->
<html>
<head>
<title>Click to Turn on or OFF the LED in the background</title>
</head>
<body bgcolor="#FF9933">
<?php
// Check of LED2 is set. If it is use it
if (isset($_POST["LED2"]))
{
$LED2= $_POST["LED2"];
//echo "<b>$LED2</b>";
}
else
{
$LED2 ="";
}
if ($LED2 == "ON")
{
// Set led2 ON by calling the Arduino using fopen
//ini_set("allow_url_fopen On", true);
$h = @fopen("http://192.168.1.5/?LED2=ON", "rb");
}
else if ($LED2 == "OFF")
{
// Set led2 OFF by calling the Arduino using fopen
//ini_set("allow_url_fopen On", true);
$h= @fopen("http://192.168.1.5/?LED2=OFF", "rb");
}
// Check of LED4 is set. If it is use it
if (isset($_POST["LED4"]))
{
$LED4= $_POST["LED4"];
//echo "<b>LED4 is $LED4</b>";
}
else
{
$LED4 ="";
}
if ($LED4 == "ON")
{
// Set led4 ON by calling the Arduino using fopen
//ini_set("allow_url_fopen On", true);
$h = @fopen("http://192.168.1.5/?LED4=ON", "rb");
}
else if ($LED4 == "OFF")
{
// Set led4 OFF by calling the Arduino using fopen
//ini_set("allow_url_fopen On", true);
$h= @fopen("http://192.168.1.5/?LED4=OFF", "rb");
}
?>
<!-- LED2 FORM -->
<table>
<tr><td colspan="2"><font size="4" color="yellow">Turn on and off the LED2</font></H4></td></tr>
<tr><td>
<form action="led2.php" method="post">
<input type="hidden" name="LED2" value="ON">
<input type="submit" name="submit" value="ON">
</form>
</td><td>
<form action="led2.php" method="post">
<input type="hidden" name="LED2" value="OFF">
<input type="submit" name="submit" value="OFF">
</form>
</td></tr>
</table>
<table>
<tr><td colspan="2"><font size="4" color="green">Turn on and off the LED4</font></td></tr>
<tr><td>
<form action="led2.php" method="post">
<input type="hidden" name="LED4" value="ON">
<input type="submit" name="submit" value="ON">
</form>
</td><td>
<form action="led2.php" method="post">
<input type="hidden" name="LED4" value="OFF">
<input type="submit" name="submit" value="OFF">
</form>
</td></tr>
</table>
</body>
</html>
Arduino code
/*
Winlkeink
August 2012
For feedback, comments and questions go to winkleink.blogspot.com
Script to allow the controling on the Arduino over Ethernet using an ENC28J60 Ethernet socket and the Ethercard library
Assigning Static IP for the Arduino so I can know exactly which Arduino I am controlling
For this example the request is either http://192.168.1.5/?LED2=ON or http://192.168.1.5/?LED2=OFF
These can be called directly but then the Arduino would have to be the web server and present back the web page
with the option to turn the LED off or ON
For this example I am controlling the Arduino from a webserver on my PC (XAMP) using a PHP script.
*/
// I took took inspiration from the following 2 examples
// The BackSoon example provided with the EtherCard library
// Present a "Will be back soon web page", as stand-in webserver.
// 2011-01-30 <jc@wippler.nl> http://opensource.org/licenses/mit-license.php
// Example from the Internet
// https://github.com/lucadentella/enc28j60_tutorial/blob/master/_5_BasicServer/_5_BasicServer.ino
#include <EtherCard.h>
// ethernet mac address - must be unique on your network
static byte mymac[] = { 0x74,0x69,0x69,0x2D,0x30,0x31 };
// ethernet interface ip address
static byte myip[] = { 192,168,1,5 };
// gateway ip address
static byte gwip[] = { 192,168,1,1 };
byte Ethernet::buffer[500]; // tcp/ip send and receive buffer
// Using a Variable for the Pin, but it is not necessary
const int ledPin2 = 2;
const int ledPin4 = 4;
// Some stuff for responding to the request
char* on = "ON";
char* off = "OFF";
char* statusLabel;
char* buttonLabel;
// Small web page to return so the request is completed
char page[] PROGMEM =
"HTTP/1.0 503 Service Unavailable\r\n"
"Content-Type: text/html\r\n"
"Retry-After: 600\r\n"
"\r\n"
"<html>"
"<head><title>"
"Arduino 192.168.1.5"
"</title></head>"
"<body>"
"<h3>Arduino 192.168.1.5</h3>"
"</body>"
"</html>"
;
void setup(){
// Set Pin2 to be an Output
pinMode(ledPin2, OUTPUT);
// Set Pin4 to be an Output
pinMode(ledPin4, OUTPUT);
// Scary complex intializing of the EtherCard - I don't understand this stuff (yet0
ether.begin(sizeof Ethernet::buffer, mymac);
// Set IP using Static
ether.staticSetup(myip, gwip);
}
void loop(){
word len = ether.packetReceive();
word pos = ether.packetLoop(len);
// IF LED2=ON turn it ON
if(strstr((char *)Ethernet::buffer + pos, "GET /?LED2=ON") != 0) {
Serial.println("Received ON command");
digitalWrite(ledPin2, HIGH);
}
// IF LED2=OFF turn it OFF
if(strstr((char *)Ethernet::buffer + pos, "GET /?LED2=OFF") != 0) {
Serial.println("Received OFF command");
digitalWrite(ledPin2, LOW);
}
// IF LED4=ON turn it ON
if(strstr((char *)Ethernet::buffer + pos, "GET /?LED4=ON") != 0) {
Serial.println("Received ON command");
digitalWrite(ledPin4, HIGH);
}
// IF LED4=OFF turn it OFF
if(strstr((char *)Ethernet::buffer + pos, "GET /?LED4=OFF") != 0) {
Serial.println("Received OFF command");
digitalWrite(ledPin4, LOW);
}
//Return a page so the request is completed.
memcpy_P(ether.tcpOffset(), page, sizeof page);
ether.httpServerReply(sizeof page - 1);
}
If you want more details on using the ENC28J60 check out my previous post on it. It gives details on wiring and various libraries for it.
