Hola buena tardes.
Les comento que estoy realizando un proyecto con Shild ethernet y un sensor de humedad y temperatura el cual quiero realizar una pagina web con los datos del sensor DHT21 , pero la pagina que creada con un editor y puesta en una tarjeta sd lo cual con el programa llamo a la pagina mi consulta es como guardar los datos del sensor y mostrarlos dentro de la pagina , ya que también necesito agregar un historial de las temperaturas
Por su atención muchas gracias les dejare el código .
#include <SPI.h>
#include <Ethernet.h>
#include <SD.h>
#include <DHT.h>
// size of buffer used to capture HTTP requests
#define REQ_BUF_SZ 20
#define DHTTYPE DHT21
#define DHTPIN 2 // Conecto el sensor al pin 2
DHT dht(DHTPIN, DHTTYPE);
// MAC address from Ethernet shield sticker under board
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 0, 3); // IP address, may need to change depending on network
EthernetServer server(80); // create a server at port 80
File webFile;
char HTTP_req[REQ_BUF_SZ] = {0}; // buffered HTTP request stored as null terminated string
char req_index = 0; // index into HTTP_req buffer
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.");
Ethernet.begin(mac, ip); // initialize Ethernet device
server.begin(); // start to listen for clients
}
void loop()
{
float h = dht.readHumidity();
float t = dht.readTemperature();
if (isnan(t) || isnan(h))
Serial.println("Failed to read from DHT");
else {
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++;
}
// print HTTP request character to serial monitor
Serial.print(c);
// last line of client request is blank and ends with \n
// respond to client only after last line received
if (c == '\n' && currentLineIsBlank) {
// open requested web page file
if (StrContains(HTTP_req, "GET / ") || StrContains(HTTP_req, "GET /index.htm")) {
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println("Connnection: close");
client.println("<!DOCTYPE HTML>");
client.println("<html>");
client.println("");
webFile = SD.open("index.htm");
client.println("</html>");
client.print(h +10 );
client.print(t);
}
else if (StrContains(HTTP_req, "GET /historico.htm")) {
client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/html");
client.println("Connnection: close");
client.println();
webFile = SD.open("historico.htm");
}
else if (StrContains(HTTP_req, "GET /logo.png")) {
webFile = SD.open("logo.png");
if (webFile) {
client.println("HTTP/1.1 200 OK");
client.println();
}
}
if (webFile) {
while(webFile.available()) {
client.write(webFile.read()); // send web page to client
}
webFile.close();
}
// 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)
}
// 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;
}