Arduino + Ajax

Projects Programming
1

Hello. My problem is I am new in Arduino programming and I would like to create an arduino webserver wich refreshes its analog data via ajax.

I started by basic ethernet code but I not understand how can I put ajax code. Can somebody explain me? thank you. Andras

#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>


byte mac[] = {
  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED
};
IPAddress ip(192, 168, 1, 20);
EthernetServer server(80);

void setup() {
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }


  // start the Ethernet connection and the server:
  Ethernet.begin(mac, ip);
  server.begin();
  Serial.print("server is at ");
  Serial.println(Ethernet.localIP());
}


void loop() {
  // listen for incoming clients
  EthernetClient client = server.available();
  if (client) {
    Serial.println("new client");
    // an http request ends with a blank line
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        Serial.write(c);
        // 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("Connection: close");  // the connection will be closed after completion of the response
          client.println("Refresh: 5");  // refresh the page automatically every 5 sec
          client.println();
          client.println("<!DOCTYPE HTML>");
          client.println("<html>");
          // output the value of each analog input pin
          for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
            int sensorReading = analogRead(analogChannel);
            client.print("analog input ");
            client.print(analogChannel);
            client.print(" is ");
            client.print(sensorReading);
            client.println("
");
          }
          client.println("</html>");
          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();
    Serial.println("client disconnected");
    Ethernet.maintain();
  }
}
2

Do you know how to use Ajax on a PC?

If not I suggest you learn that first as it is a much simpler environment and there are tons of examples on the web.

Please modify your Post and use the code button </> so your code looks like this and is easy to copy to a text editor

...R

3

The below site might have info.

4

Thank you for the answer

5

Here's an example using JSON rather than AJAX. Same idea, though:

http://playground.arduino.cc/Code/WebServerJson

6

PaulMurrayCbr:
Here's an example using JSON rather than AJAX.

AFAIK JSON is an alternative to XML, not AJAX.

AFAIK you can use either JSON or XML with AJAX (though I suppose, strictly speaking, it should then be AJAJ :slight_smile: )

...R