Im working with the arduino uno and ethernet shield W5100.
Im trying to find some code which will read a URL and put that into three custom variables.
When I call the url 192.168.1.102?var1=100&var2=101&var3=102 the serial monitor returns GET /?var1=100&var2=101&var3=102 HTTP/1.1 for the following code:
Serial.println(readString.indexOf("?"))
What I want to do is read the values of the variable in the URI and put it in three different variables. How can I do this?
When I call the url 192.168.1.102?var1=100&var2=101&var3=102 the serial monitor returns GET /?var1=100&var2=101&var3=102 HTTP/1.1 for the following code:
No, it doesn't. The indexOf() function returns an int. "GET /?var1=100&var2=101&var3=102 HTTP/1.1" is not an int.
Post all of your code.
You're right, after shuffling around that line of code its returning "5" so now I'm more baffled than before. It is returning the line I quoted, but I was being a bit dopey as its in a If statement.
Heres the full code, sorry if its a bit messy.
//zoomkat 12-8-11
//simple button GET with iframe code
//for use with IDE 1.0
//open serial monitor to see what the arduino receives
//use the \ slash to escape the " in the html
//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>
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(80); //server port
Servo servo1; // create servo object to control a servo
Servo servo2; // create servo object to control a servo
String readString;
//////////////////////
void setup(){
servo1.attach(7); // attaches the servo on pin 7 to the servo object
servo2.attach(8); // attaches the servo on pin 8 to the servo object
pinMode(9, OUTPUT); //pin selected to control
//start Ethernet
Ethernet.begin(mac, ip, gateway, subnet);
server.begin();
//enable serial data print
Serial.begin(9600);
Serial.println("server LED 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
//now output HTML data header
if(readString.indexOf('?') >=0) { //don't send new page
client.println("HTTP/1.1 204 Zoomkat");
client.println();
client.println();
}
else {
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>Location Clock 0.1.1</TITLE>");
client.println("</HEAD>");
client.println("<BODY>");
client.println("<H1>Location Clock 0.1.1</H1>");
client.println("<a href=\"/?on\" target=\"inlineframe\">ON</a>");
client.println("<a href=\"/?off#the#wall\" target=\"inlineframe\">OFF</a>");
//client.println("<IFRAME name=inlineframe src=\"res://D:/WINDOWS/dnserror.htm\" width=1 height=1\">");
client.println("<IFRAME name=inlineframe style=\"display:none\" >");
client.println("</IFRAME>");
client.println("</BODY>");
client.println("</HTML>");
}
delay(1);
//stopping client
client.stop();
//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
///////////////////// control arduino pin
if(readString.indexOf("on") >0)//checks for on
{
Serial.println("[begin URI]");
Serial.println(readString.indexOf("?"));
Serial.println("[end URI]");
digitalWrite(9, HIGH); // set pin 9 high
Serial.println("Led On");
}
if(readString.indexOf("off") >0)//checks for off
{
digitalWrite(9, LOW); // set pin 9 low
Serial.println("Led Off");
}
//clearing string for next read
readString="";
}
}
}
}
}
When you enter a URL in a browser, the browser software converts the URL to a GET request. That is where the "GET /?var1=100&var2=101&var3=102 HTTP/1.1" is coming from.
The call to indexOf() is missing from this code, but what it does is find the position of the ? in "GET /?var1=100&var2=101&var3=102 HTTP/1.1". 0 is G, 1 is E, etc., so the ? is in position 5.
You could create a substring of the rest of the data in readString, or you could locate the & that ends the first name=value token. Create a substring that contains just the first name=value token.
Then, you can separate the name=value token into name and value tokens, and them convert the value token to a number, using atoi(). Store that number somewhere based on the name token.
Thank you PaulS, you've solved a problem I was unaware of, and substring was the solution to the rest of it.
I've used substring to read in the segments from the GET request of 192.168.1.102?user=123456789&pass=123456789&servo1=123&servo2=456&servo3=789, the segment of code reads:
Serial.println("[begin URI]");
Serial.println(readString); //print to serial monitor for debuging
Serial.println("[end URI]");
Serial.println("[begin servo positions]");
Serial.println("servo1: " + readString.substring(43,46));
Serial.println("servo2: " + readString.substring(54,57));
Serial.println("servo3: " + readString.substring(65,68));
Serial.println("[end servo positions]");
Which displays in the serial monitor as:
[begin URI]
GET /?user=123456789&pass=123456789&servo1=123&servo2=456&servo3=789 HTTP/1.1[end URI]
[begin servo positions]
servo1: 123
servo2: 456
servo3: 789
[end servo positions]
Thank you again.
My full code now reads:
//zoomkat 12-8-11
//simple button GET with iframe code
//for use with IDE 1.0
//open serial monitor to see what the arduino receives
//use the \ slash to escape the " in the html
//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>
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(80); //server port
Servo servo1; // create servo object to control a servo
Servo servo2; // create servo object to control a servo
String readString;
//////////////////////
void setup(){
servo1.attach(7); // attaches the servo on pin 7 to the servo object
servo2.attach(8); // attaches the servo on pin 8 to the servo object
pinMode(9, OUTPUT); //pin selected to control
//start Ethernet
Ethernet.begin(mac, ip, gateway, subnet);
server.begin();
//enable serial data print
Serial.begin(9600);
Serial.println("server LED 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
//now output HTML data header
if(readString.indexOf('?') >=0) { //don't send new page
client.println("HTTP/1.1 204 Zoomkat");
client.println();
client.println();
}
else {
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>Location Clock 0.1.1</TITLE>");
client.println("</HEAD>");
client.println("<BODY>");
client.println("<H1>Location Clock 0.1.1</H1>");
client.println("<a href=\"/?on\" target=\"inlineframe\">ON</a>");
client.println("<a href=\"/?off#the#wall\" target=\"inlineframe\">OFF</a>");
//client.println("<IFRAME name=inlineframe src=\"res://D:/WINDOWS/dnserror.htm\" width=1 height=1\">");
client.println("<IFRAME name=inlineframe style=\"display:none\" >");
client.println("</IFRAME>");
client.println("</BODY>");
client.println("</HTML>");
}
delay(1);
//stopping client
client.stop();
//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
//@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
Serial.println("[begin URI]");
Serial.println(readString); //print to serial monitor for debuging
Serial.println("[end URI]");
Serial.println("[begin servo positions]");
Serial.println("servo1: " + readString.substring(43,46));
Serial.println("servo2: " + readString.substring(54,57));
Serial.println("servo3: " + readString.substring(65,68));
Serial.println("[end servo positions]");
///////////////////// control arduino pin
if(readString.indexOf("on") >0)//checks for on
{
digitalWrite(9, HIGH); // set pin 9 high
Serial.println("Led On");
}
if(readString.indexOf("off") >0)//checks for off
{
digitalWrite(9, LOW); // set pin 9 low
Serial.println("Led Off");
}
//clearing string for next read
readString="";
}
}
}
}
}
The below link has info on some string operations that can be used in various ways to get information from the string. Below is some simple serial monitor code that can be used for parse testing using the serial monitor.
// zoomkat 7-30-11 serial I/O string test
// type a string in serial monitor. then send or enter
// for IDE 0019 and later
String readString;
void setup() {
Serial.begin(9600);
Serial.println("serial test 0021"); // so I can keep track of what is loaded
}
void loop() {
while (Serial.available()) {
delay(2); //delay to allow byte to arrive in input buffer
char c = Serial.read();
readString += c;
}
if (readString.length() >0) {
Serial.println(readString);
////do parse testing here
//////
readString="";
}
}