Bom dia a todos.

Pessoal tenho um código aqui que eu peguei para estudo na internet onde ele usa um Arduino Uno e um modulo Ethernet Shield com cartão SD.

Ja tentei de varias formas mas não consegui. O que eu gostaria era que no link que aparece na pagina web criada dentro do shield eu conseguisse fazer o download dos arquivos, mas ao invés disso ele me mostra uma pagina web em branco.

Por acaso aqui alguém ja conseguiu fazer de alguma forma o download dos arquivos que tem no SDCARD via browser?

O codigo que eu peguei esta abaixo.

/*
* USERS OF ARDUINO 0023 AND EARLIER: use the 'SDWebBrowse.pde' sketch...
* 'SDWebBrowse.ino' can be ignored.
* USERS OF ARDUINO 1.0 AND LATER: **DELETE** the 'SDWebBrowse.pde' sketch
* and use ONLY the 'SDWebBrowse.ino' file. By default, BOTH files will
* load when using the Sketchbook menu, and the .pde version will cause
* compiler errors in 1.0. Delete the .pde, then load the sketch.
*
* I can't explain WHY this is necessary, but something among the various
* libraries here appears to be wreaking inexplicable havoc with the
* 'ARDUINO' definition, making the usual version test unusable (BOTH
* cases evaluate as true). FML.
*/

/*
* This sketch uses the microSD card slot on the Arduino Ethernet shield
* to serve up files over a very minimal browsing interface
*
* Some code is from Bill Greiman's SdFatLib examples, some is from the
* Arduino Ethernet WebServer example and the rest is from Limor Fried
* (Adafruit) so its probably under GPL
*
* Tutorial is at http://www.ladyada.net/learn/arduino/ethfiles.html
* Pull requests should go to http://github.com/adafruit/SDWebBrowse
*/

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

/************ ETHERNET STUFF ************/
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
byte ip[] = { 192, 168, 1, 80 };
EthernetServer server(80);

/************ SDCARD STUFF ************/
Sd2Card card;
SdVolume volume;
SdFile root;
SdFile file;

// store error strings in flash to save RAM
#define error(s) error_P(PSTR(s))

void error_P(const char* str) {
PgmPrint("error: ");
SerialPrintln_P(str);
if (card.errorCode()) {
PgmPrint("SD error: ");
Serial.print(card.errorCode(), HEX);
Serial.print(',');
Serial.println(card.errorData(), HEX);
}
while(1);
}

void setup() {
Serial.begin(9600);

PgmPrint("Free RAM: ");
Serial.println(FreeRam()); 

// initialize the SD card at SPI_HALF_SPEED to avoid bus errors with
// breadboards. use SPI_FULL_SPEED for better performance.
pinMode(10, OUTPUT); // set the SS pin as an output (necessary!)
digitalWrite(10, HIGH); // but turn off the W5100 chip!

if (!card.init(SPI_HALF_SPEED, 4)) error("card.init failed!");

// initialize a FAT volume
if (!volume.init(&card)) error("vol.init failed!");

PgmPrint("Volume is FAT");
Serial.println(volume.fatType(),DEC);
Serial.println();

if (!root.openRoot(&volume)) error("openRoot failed");

// list file in root with date and size
PgmPrintln("Files found in root:");
root.ls(LS_DATE | LS_SIZE);
Serial.println();

// Recursive list of all directories
PgmPrintln("Files found in all dirs:");
root.ls(LS_R);

Serial.println();
PgmPrintln("Done");

// Debugging complete, we start the server!
Ethernet.begin(mac, ip );
server.begin();
}

void ListFiles(EthernetClient client, uint8_t flags) {
// This code is just copied from SdFile.cpp in the SDFat library
// and tweaked to print to the client output in html!
dir_t p;

root.rewind();
client.println("<ul>");
while (root.readDir(&p) > 0) {
// done if past last used entry
if (p.name[0] == DIR_NAME_FREE) break;

// skip deleted entry and entries for . and ..
if (p.name[0] == DIR_NAME_DELETED || p.name[0] == '.') continue;

// only list subdirectories and files
if (!DIR_IS_FILE_OR_SUBDIR(&p)) continue;

// print any indent spaces
client.print("<li><a href=\"");
for (uint8_t i = 0; i < 11; i++) {
if (p.name[i] == ' ') continue;
if (i == 8) {
client.print('.');
}
client.print((char)p.name[i]);
}
client.print("\">");

// print file name with possible blank fill
for (uint8_t i = 0; i < 11; i++) {
if (p.name[i] == ' ') continue;
if (i == 8) {
client.print('.');
}
client.print((char)p.name[i]);
}

client.print("</a>");

if (DIR_IS_SUBDIR(&p)) {
client.print('/');
}

// print modify date/time if requested
if (flags & LS_DATE) {
root.printFatDate(p.lastWriteDate);
client.print(' ');
root.printFatTime(p.lastWriteTime);
}
// print size if requested
if (!DIR_IS_SUBDIR(&p) && (flags & LS_SIZE)) {
client.print(' ');
// client.print(p.fileSize);
}
client.println("</li>");
}
client.println("</ul>");
}

// How big our line buffer should be. 100 is plenty!
#define BUFSIZ 100

void loop()
{
char clientline[BUFSIZ];
int index = 0;

EthernetClient client = server.available();
if (client) {
// an http request ends with a blank line
boolean current_line_is_blank = true;

// reset the input buffer
index = 0;

while (client.connected()) {
if (client.available()) {
char c = client.read();

// If it isn't a new line, add the character to the buffer
if (c != '\n' && c != '\r') {
clientline[index] = c;
index++;
// are we too big for the buffer? start tossing out data
if (index >= BUFSIZ) 
index = BUFSIZ -1;

// continue to read more data!
continue;
}

// got a \n or \r new line, which means the string is done
clientline[index] = 0;

// Print it out for debugging
Serial.println(clientline);

// Look for substring such as a request to get the root file
if (strstr(clientline, "GET / ") != 0) {
// send a standard http response header

client.println("HTTP/1.1 200 OK");
client.println("Content-Type: application/force-download");
client.println("Content-Type: application/octet-stream;");
client.println("Content-Type: text/html");
client.println("Connection: close");
client.println("<!DOCTYPE HTML>");
client.println();

// print all the files, use a helper to keep it clean
client.println("<h2>Files:</h2>");

//Lista todos os arquivos do cartao para download
ListFiles(client, LS_SIZE);

} else if (strstr(clientline, "GET /") != 0) {
// this time no space after the /, so a sub-file!
char *filename;

filename = clientline + 5; // look after the "GET /" (5 chars)
// a little trick, look for the " HTTP/1.1" string and 
// turn the first character of the substring into a 0 to clear it out.
(strstr(clientline, " HTTP"))[0] = 0;

// print the file we want
Serial.println(filename);

if (! file.open(&root, filename, O_READ)) {
client.println("HTTP/1.1 404 Not Found");
client.println("Content-Type: text/html");
client.println();
client.println("<h2>File Not Found!</h2>");
break;
}

Serial.println("Opened!");

client.println("HTTP/1.1 200 OK");
client.println("Content-Type: text/plain");
client.println();

int16_t c;
while ((c = file.read()) > 0) {
// uncomment the serial to debug (slow!)
//Serial.print((char)c);
client.print((char)c);
}
file.close();
} else {
// everything else is a 404
client.println("HTTP/1.1 404 Not Found");
client.println("Content-Type: text/html");
client.println();
client.println("<h2>File Not Found!</h2>");
}
break;
}
}
// give the web browser time to receive the data
delay(1);
client.stop();
}
}