wtrssn/part9_AJAXautoDigitalAnalogReading.ino

## part9_AJAXautoDigitalAnalogReading.ino
/*--------------------------------------------------------------
  Program:      eth_websrv_AJAX_IN

  Description:  Uses Ajax to update the state of two switches
                and an analog input on a web page. The Arduino
                web server hosts the web page.
                Does not use the SD card.

  Hardware:     Arduino Uno and official Arduino Ethernet
                shield. Should work with other Arduinos and
                compatible Ethernet shields.

  Software:     Developed using Arduino 1.0.3 software
                Should be compatible with Arduino 1.0 +

  References:   - WebServer example by David A. Mellis and
                  modified by Tom Igoe
                - Ethernet library documentation:
                  http://arduino.cc/en/Reference/Ethernet
                - Learning PHP, MySQL & JavaScript by
                  Robin Nixon, O'Reilly publishers

  Date:         20 February 2013

  Author:       W.A. Smith, http://startingelectronics.org
--------------------------------------------------------------*/

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

// MAC address from Ethernet shield sticker under board
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 1, 177); // IP address, may need to change depending on network
EthernetServer server(80);  // create a server at port 80

String HTTP_req;            // stores the HTTP request

const int SWITCH_02 = 2;
const int SWITCH_03 = 3;
const int POTENC_00 = 0;

void setup()
{
    Ethernet.begin(mac, ip);  // initialize Ethernet device
    server.begin();           // start to listen for clients
    Serial.begin(9600);       // for diagnostics
    pinMode(SWITCH_02, INPUT);        // switch is attached to Arduino pin 7
    pinMode(SWITCH_03, INPUT);        // switch is attached to Arduino pin 8
}

void loop()
{
    EthernetClient client = server.available();  // try to get client

    if (client) {  // got client?
        boolean currentLineIsBlank = true;
        while (client.connected()) {
            if (client.available()) {   // client data available to read
                char c = client.read(); // read 1 byte (character) from client
                HTTP_req += c;  // save the HTTP request 1 char at a time
                // last line of client request is blank and ends with \n
                // respond to client only after last line received
                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: keep-alive");
                    client.println();
                    // AJAX request for switch state
                    if (HTTP_req.indexOf("ajax_switch") > -1) {
                        // read switch state and analog input
                        GetAjaxData(client);
                    }
                    else {  // HTTP request for web page
                        // send web page - contains JavaScript with AJAX calls
                        client.println("<!DOCTYPE html>");
                        client.println("<html>");
                        client.println("<head>");
                        client.println("<title>Arduino Web Page</title>");
                        client.println("<script>");
                        client.println("function GetSwitchAnalogData() {");
                        client.println(
                            "nocache = \"&nocache=\" + Math.random() * 1000000;");
                        client.println("var request = new XMLHttpRequest();");
                        client.println("request.onreadystatechange = function() {");
                        client.println("if (this.readyState == 4) {");
                        client.println("if (this.status == 200) {");
                        client.println("if (this.responseText != null) {");
                        client.println("document.getElementById(\"sw_an_data\")\.innerHTML = this.responseText;");
                        client.println("}}}}");
                        client.println("request.open(\"GET\", \"ajax_switch\" + nocache, true);");
                        client.println("request.send(null);");
                        client.println("setTimeout('GetSwitchAnalogData()', 1000);");
                        client.println("}");
                        client.println("</script>");
                        client.println("</head>");
                        client.println("<body onload=\"GetSwitchAnalogData()\">");
                        client.println("<h1>Arduino AJAX Input</h1>");
                        client.println("<div id=\"sw_an_data\">");
                        client.println("</div>");
                        client.println("</body>");
                        client.println("</html>");
                    }
                    // display received HTTP request on serial port
                    Serial.print(HTTP_req);
                    HTTP_req = "";            // finished with request, empty string
                    break;
                }
                // every line of text received from the client ends with \r\n
                if (c == '\n') {
                    // last character on line of received text
                    // starting new line with next character read
                    currentLineIsBlank = true;
                }
                else if (c != '\r') {
                    // a text character was received from client
                    currentLineIsBlank = false;
                }
            } // end if (client.available())
        } // end while (client.connected())
        delay(1);      // give the web browser time to receive the data
        client.stop(); // close the connection
    } // end if (client)
}

// send the state of the switch to the web browser
void GetAjaxData(EthernetClient cl)
{
    int analog_val;

    if (digitalRead(SWITCH_02)) {
        cl.println("<p>Switch 2 state: ON</p>");
    }
    else {
        cl.println("<p>Switch 2 state: OFF</p>");
    }
    if (digitalRead(SWITCH_03)) {
        cl.println("<p>Switch 3 state: ON</p>");
    }
    else {
        cl.println("<p>Switch 3 state: OFF</p>");
    }
    // read analog pin A2
    analog_val = analogRead(POTENC_00);
    cl.print("<p>Analog A0: ");
    cl.print(analog_val);
    cl.println("</p>");
}
	/*--------------------------------------------------------------
	Program: eth_websrv_AJAX_IN

	Description: Uses Ajax to update the state of two switches
	and an analog input on a web page. The Arduino
	web server hosts the web page.
	Does not use the SD card.

	Hardware: Arduino Uno and official Arduino Ethernet
	shield. Should work with other Arduinos and
	compatible Ethernet shields.

	Software: Developed using Arduino 1.0.3 software
	Should be compatible with Arduino 1.0 +

	References: - WebServer example by David A. Mellis and
	modified by Tom Igoe
	- Ethernet library documentation:
	http://arduino.cc/en/Reference/Ethernet
	- Learning PHP, MySQL & JavaScript by
	Robin Nixon, O'Reilly publishers

	Date: 20 February 2013

	Author: W.A. Smith, http://startingelectronics.org
	--------------------------------------------------------------*/

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

	// MAC address from Ethernet shield sticker under board
	byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
	IPAddress ip(192, 168, 1, 177); // IP address, may need to change depending on network
	EthernetServer server(80); // create a server at port 80

	String HTTP_req; // stores the HTTP request

	const int SWITCH_02 = 2;
	const int SWITCH_03 = 3;
	const int POTENC_00 = 0;

	void setup()
	{
	Ethernet.begin(mac, ip); // initialize Ethernet device
	server.begin(); // start to listen for clients
	Serial.begin(9600); // for diagnostics
	pinMode(SWITCH_02, INPUT); // switch is attached to Arduino pin 7
	pinMode(SWITCH_03, INPUT); // switch is attached to Arduino pin 8
	}

	void loop()
	{
	EthernetClient client = server.available(); // try to get client

	if (client) { // got client?
	boolean currentLineIsBlank = true;
	while (client.connected()) {
	if (client.available()) { // client data available to read
	char c = client.read(); // read 1 byte (character) from client
	HTTP_req += c; // save the HTTP request 1 char at a time
	// last line of client request is blank and ends with \n
	// respond to client only after last line received
	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: keep-alive");
	client.println();
	// AJAX request for switch state
	if (HTTP_req.indexOf("ajax_switch") > -1) {
	// read switch state and analog input
	GetAjaxData(client);
	}
	else { // HTTP request for web page
	// send web page - contains JavaScript with AJAX calls
	client.println("<!DOCTYPE html>");
	client.println("<html>");
	client.println("<head>");
	client.println("<title>Arduino Web Page</title>");
	client.println("<script>");
	client.println("function GetSwitchAnalogData() {");
	client.println(
	"nocache = \"&nocache=\" + Math.random() * 1000000;");
	client.println("var request = new XMLHttpRequest();");
	client.println("request.onreadystatechange = function() {");
	client.println("if (this.readyState == 4) {");
	client.println("if (this.status == 200) {");
	client.println("if (this.responseText != null) {");
	client.println("document.getElementById(\"sw_an_data\")\.innerHTML = this.responseText;");
	client.println("}}}}");
	client.println("request.open(\"GET\", \"ajax_switch\" + nocache, true);");
	client.println("request.send(null);");
	client.println("setTimeout('GetSwitchAnalogData()', 1000);");
	client.println("}");
	client.println("</script>");
	client.println("</head>");
	client.println("<body onload=\"GetSwitchAnalogData()\">");
	client.println("<h1>Arduino AJAX Input</h1>");
	client.println("<div id=\"sw_an_data\">");
	client.println("</div>");
	client.println("</body>");
	client.println("</html>");
	}
	// display received HTTP request on serial port
	Serial.print(HTTP_req);
	HTTP_req = ""; // finished with request, empty string
	break;
	}
	// every line of text received from the client ends with \r\n
	if (c == '\n') {
	// last character on line of received text
	// starting new line with next character read
	currentLineIsBlank = true;
	}
	else if (c != '\r') {
	// a text character was received from client
	currentLineIsBlank = false;
	}
	} // end if (client.available())
	} // end while (client.connected())
	delay(1); // give the web browser time to receive the data
	client.stop(); // close the connection
	} // end if (client)
	}

	// send the state of the switch to the web browser
	void GetAjaxData(EthernetClient cl)
	{
	int analog_val;

	if (digitalRead(SWITCH_02)) {
	cl.println("<p>Switch 2 state: ON</p>");
	}
	else {
	cl.println("<p>Switch 2 state: OFF</p>");
	}
	if (digitalRead(SWITCH_03)) {
	cl.println("<p>Switch 3 state: ON</p>");
	}
	else {
	cl.println("<p>Switch 3 state: OFF</p>");
	}
	// read analog pin A2
	analog_val = analogRead(POTENC_00);
	cl.print("<p>Analog A0: ");
	cl.print(analog_val);
	cl.println("</p>");
	}