Hello !
This time I’m having a little problem with combining two functionalities from two codes.
Till today, I was using web serwer code from this tutorial : http://startingelectronics.com/tutorials/arduino/ethernet-shield-web-server-tutorial/SD-card-AJAX-XML-web-server/
My arduino is sending 14 floats and 24 boolean variables to the web. There is 4 files on SD card. With this code everything works ok but it is SOOOOOOO SLOOOOW…
Here is an example from this tutorial :
/*--------------------------------------------------------------
#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>
// size of buffer used to capture HTTP requests
#define REQ_BUF_SZ 50
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 0, 20);
EthernetServer server(80);
File webFile;
char HTTP_req[REQ_BUF_SZ] = {0};
char req_index = 0;
void setup()
{
// disable Ethernet chip
pinMode(10, OUTPUT);
digitalWrite(10, HIGH);
Serial.begin(9600); // for debugging
// initialize SD card
Serial.println("Initializing SD card...");
if (!SD.begin(4)) {
Serial.println("ERROR - SD card initialization failed!");
return; // init failed
}
Serial.println("SUCCESS - SD card initialized.");
// check for index.htm file
if (!SD.exists("index.htm")) {
Serial.println("ERROR - Can't find index.htm file!");
return; // can't find index file
}
Serial.println("SUCCESS - Found index.htm file.");
pinMode(7, INPUT); // switch is attached to Arduino pin 7
pinMode(8, INPUT); // switch is attached to Arduino pin 8
Ethernet.begin(mac, ip); // initialize Ethernet device
server.begin(); // start to listen for clients
}
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
// buffer first part of HTTP request in HTTP_req array (string)
// leave last element in array as 0 to null terminate string (REQ_BUF_SZ - 1)
if (req_index < (REQ_BUF_SZ - 1)) {
HTTP_req[req_index] = c; // save HTTP request character
req_index++;
}
// 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");
// remainder of header follows below, depending on if
// web page or XML page is requested
// Ajax request - send XML file
if (StrContains(HTTP_req, "ajax_inputs")) {
// send rest of HTTP header
client.println("Content-Type: text/xml");
client.println("Connection: keep-alive");
client.println();
// send XML file containing input states
XML_response(client);
}
else { // web page request
// send rest of HTTP header
client.println("Content-Type: text/html");
client.println("Connection: keep-alive");
client.println();
// send web page
webFile = SD.open("index.htm"); // open web page file
if (webFile) {
while(webFile.available()) {
client.write(webFile.read()); // send web page to client
}
webFile.close();
}
}
// display received HTTP request on serial port
Serial.print(HTTP_req);
// reset buffer index and all buffer elements to 0
req_index = 0;
StrClear(HTTP_req, REQ_BUF_SZ);
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 XML file with switch statuses and analog value
void XML_response(EthernetClient cl)
{
int analog_val;
cl.print("<?xml version = \"1.0\" ?>");
cl.print("<inputs>");
cl.print("<button1>");
if (digitalRead(7)) {
cl.print("ON");
}
else {
cl.print("OFF");
}
cl.print("</button1>");
cl.print("<button2>");
if (digitalRead(8)) {
cl.print("ON");
}
else {
cl.print("OFF");
}
cl.print("</button2>");
// read analog pin A2
analog_val = analogRead(2);
cl.print("<analog1>");
cl.print(analog_val);
cl.print("</analog1>");
cl.print("</inputs>");
}
// sets every element of str to 0 (clears array)
void StrClear(char *str, char length)
{
for (int i = 0; i < length; i++) {
str[i] = 0;
}
}
// searches for the string sfind in the string str
// returns 1 if string found
// returns 0 if string not found
char StrContains(char *str, char *sfind)
{
char found = 0;
char index = 0;
char len;
len = strlen(str);
if (strlen(sfind) > len) {
return 0;
}
while (index < len) {
if (str[index] == sfind[found]) {
found++;
if (strlen(sfind) == found) {
return 1;
}
}
else {
found = 0;
}
index++;
}
return 0;
}
Today I found web server code written by SurferTim :http://playground.arduino.cc/Code/WebServerST
And it is incredibly fast ! I tried to adapt it to my needs and I made arduino serving my 4 pages with no problem. But I cannot get ajax / xml part to work. I’m not sure where and how should I place this piece of code from tutorial in Tim’s code :
if (StrContains(HTTP_req, "ajax_inputs")) {
// send rest of HTTP header
client.println("Content-Type: text/xml");
client.println("Connection: keep-alive");
client.println();
// send XML file containing input states
XML_response(client);
}
I have added XML file type in Tim’s original code.
In Tim’s code, there is :
if(strcmp(requestBuffer,"/MYTEST.PHP") == 0) {
#ifdef ServerDEBUG
Serial.println(F("dynamic page"));
#endif
And I channged it to :
if (strcmp(requestBuffer,"ajax_inputs") == 0) {
strcat_P(tBuf, PSTR("Connection: keep-alive"));
client.write(tBuf);
strcat_P(tBuf, PSTR("\r\n\r\n"));
client.write(tBuf);
I tried many things but all I’m getting in serial debug messages is :“File not found” “Closed” . I can see Ajax requests every second but server cant find XML file ( because it’s not on SD card )
Could anyone tell me, how to combine this “virtual” XML file with Tim’s code or is there different way to refresh automaticaly about 40 variables on web page without reloading the page itself? Ajax approach seems perfect for this but I really need faster responding server ( WebServerST code is very fast ) .
I’m using arduino Mega and WIZ W5100.
I can’t post my whole code because is quite large.
Thanks in advance!
