A simple web server that shows the value of the analog input pins.
using an Arduino Wiznet Ethernet shield.

Circuit:
* Ethernet shield attached to pins 10, 11, 12, 13
* Analog inputs attached to pins A0 through A5 (optional)

created 18 Dec 2009
by David A. Mellis
modified 4 Sep 2010
by Tom Igoe

*/

#include
#include

// Example testing sketch for various DHT humidity/temperature sensors
// Written by ladyada, public domain

#include "DHT.h"

#define DHTPIN 2 // what pin we're connected to

// Uncomment whatever type you're using!
//#define DHTTYPE DHT11 // DHT 11
#define DHTTYPE DHT22 // DHT 22 (AM2302)
//#define DHTTYPE DHT21 // DHT 21 (AM2301)

// Connect pin 1 (on the left) of the sensor to +5V
// Connect pin 2 of the sensor to whatever your DHTPIN is
// Connect pin 4 (on the right) of the sensor to GROUND
// Connect a 10K resistor from pin 2 (data) to pin 1 (power) of the sensor

DHT dht(DHTPIN, DHTTYPE);

// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192,168,1, 177);

// Initialize the Ethernet server library
// with the IP address and port you want to use
// (port 80 is default for HTTP):
EthernetServer server(80);

// Request
int Request; // any function will see this variable

void setup() {
// start the Ethernet connection and the server:
Ethernet.begin(mac, ip);
server.begin();

// Serial.begin(9600);
// Serial.println("DHTxx test!");

// Request
Request = 0;

// DHT
dht.begin();
}

void WEBloop()
{
// listen for incoming clients
EthernetClient client = server.available();
if (client) {
// an http request ends with a blank line
boolean currentLineIsBlank = true;
while (client.connected()) {
if (client.available()) {
char c = client.read();
// if you've gotten to the end of the line (received a newline
// character) and the line is blank, the http request has ended,
// so you can send a reply
if (c == '\n' && currentLineIsBlank) {
// send a standard http response header
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println();

// output the value of each analog input pin
//for (int analogChannel = 0; analogChannel < 6; analogChannel++) { //client.print("analog input "); //client.print(analogChannel); //client.print(" is "); //client.print(analogRead(analogChannel)); //client.println("
");
//}

// Reading temperature or humidity takes about 250 milliseconds!
// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
float h = dht.readHumidity();
float t = dht.readTemperature();

// check if returns are valid, if they are NaN (not a number) then something went wrong!
if (isnan(t) || isnan(h)) {
// Serial.println("Failed to read from DHT");
//
client.print("Failed to read from DHT");
client.println("
");
} else {
// Serial.print("Humidity: ");
// Serial.print(h);
// Serial.print(" %\t");
// Serial.print("Temperature: ");
// Serial.print(t);
// Serial.println(" *C");
//
client.print("Request: ");
//client.println(random(1000));
Request = Request + 1;
client.println(Request);
//
client.print("Humidity: ");
client.print(h);
client.print(" %\t");
client.print("Temperature: ");
client.print(t);
client.println(" *C");
client.println("
");
}

break;
}
if (c == '\n') {
// you're starting a new line
currentLineIsBlank = true;
}
else if (c != '\r') {
// you've gotten a character on the current line
currentLineIsBlank = false;
}
}
}
// give the web browser time to receive the data
delay(1);
// close the connection:
client.stop();
}
}

void loop() {

//DHTloop();
WEBloop();

}

void DHTloop() {
// Reading temperature or humidity takes about 250 milliseconds!
// Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
float h = dht.readHumidity();
float t = dht.readTemperature();