I have read the book Beginning Arduino written by Michael McRoberts and I have gotten the ethernet projects working using the Arduino Ethernet Shield. I have no problem pushing data to email or a web page.
My question is how do I push data (user entering data in real time on a web page) back to the Arduino? I assume the Arduino sends the HTTP code for a web page that has blank entry fields and a SUBMIT button? And if so, then would the Arduino listen for what in response? I just want to have the user send a 2 digit code, thats all.
// Very small part of example code to read each char from web
void serialEvent() {
// Read a char
char inChar = client.read();
if (inChar == 'A1') {
//do something
} else if (inChar == 'A2') {
//do something else
etc,etc
I know I am probably not explaining this very well. If you need more explanation, please let me know.
//zoomkat 4-1-12
//simple button GET for servo and pin 5
//for use with IDE 1.0
//open serial monitor to see what the arduino receives
//use the \ slash to escape the " in the html, or use ' instead of "
//address will look like http://192.168.1.102:84 when submited
//for use with W5100 based ethernet shields
#include <SPI.h>
#include <Ethernet.h>
#include <Servo.h>
Servo myservo; // create servo object to control a servo
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
byte ip[] = { 192, 168, 1, 102 }; // ip in lan
byte gateway[] = { 192, 168, 1, 1 }; // internet access via router
byte subnet[] = { 255, 255, 255, 0 }; //subnet mask
EthernetServer server(84); //server port
String readString;
//////////////////////
void setup(){
pinMode(5, OUTPUT); //pin selected to control
//start Ethernet
Ethernet.begin(mac, ip, gateway, gateway, subnet);
server.begin();
myservo.write(90); //set initial servo position if desired
myservo.attach(7); //the pin for the servo control
//enable serial data print
Serial.begin(9600);
Serial.println("server servo/pin 5 test 1.0"); // so I can keep track of what is loaded
}
void loop(){
// Create a client connection
EthernetClient client = server.available();
if (client) {
while (client.connected()) {
if (client.available()) {
char c = client.read();
//read char by char HTTP request
if (readString.length() < 100) {
//store characters to string
readString += c;
//Serial.print(c);
}
//if HTTP request has ended
if (c == '\n') {
///////////////
Serial.println(readString); //print to serial monitor for debuging
client.println("HTTP/1.1 200 OK"); //send new page
client.println("Content-Type: text/html");
client.println();
client.println("<HTML>");
client.println("<HEAD>");
client.println("<TITLE>Arduino GET test page</TITLE>");
client.println("</HEAD>");
client.println("<BODY>");
client.println("<H1>Zoomkat's simple Arduino button</H1>");
client.println("<a href=\"/?on\">ON</a>");
client.println("<a href=\"/?off\">OFF</a>");
client.println("</BODY>");
client.println("</HTML>");
delay(1);
//stopping client
client.stop();
///////////////////// control arduino pin
if(readString.indexOf("on") >0)//checks for on
{
myservo.write(40);
digitalWrite(5, HIGH); // set pin 5 high
Serial.println("Led On");
}
if(readString.indexOf("off") >0)//checks for off
{
myservo.write(140);
digitalWrite(5, LOW); // set pin 5 low
Serial.println("Led Off");
}
//clearing string for next read
readString="";
}
}
}
}
}
" is an escaped double quote. When the string being sent contains double quotes, they need to be escaped, to distinguish them from the end of string double quote.
The / in /?on is the name of the web page (i.e. none). The ? separates the form data from the URL. The form data, a single value, since there is no & in the string, is on.