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Topic: arduino wifi shield don't open widi when sd activ (Read 2415 times) previous topic - next topic


I have a problem with the official arduino wifi shield and UNO all in R3.
When i begin SD operation, i cannot use Wifi. Here is the sketch :

Code: [Select]

  WiFi Web Server LED Blink
#include <SPI.h>
#include <WiFi.h>
#include <SD.h>

File root;

char ssid[] = "dlink";      // your network SSID (name)
char pass[] = "xxxx";   // your network password
int keyIndex = 0;                // your network key Index number (needed only for WEP)

int status = WL_IDLE_STATUS;
WiFiServer server(80);

const int chipSelect = 4;

void setup() {
  Serial.begin(9600);      // initialize serial communication
  pinMode(13, OUTPUT);      // set the LED pin mode

  Serial.print("\nInitializing SD card...");
 // pinMode(53, OUTPUT);     // change this to 53 on a mega
  pinMode(10, OUTPUT);

  if (!SD.begin(chipSelect)) {
    Serial.println("initialization failed!");
  Serial.println("initialization done.");

  root = SD.open("/");
  printDirectory(root, 0);

 digitalWrite(4,HIGH); // forcage SS SD pour d├ęsactiver SD

  // check for the presence of the shield:
  if (WiFi.status() == WL_NO_SHIELD) {
    Serial.println("WiFi shield not present");
    while (true);       // don't continue

  String fv = WiFi.firmwareVersion();
  if ( fv != "1.1.0" )
    Serial.println("Please upgrade the firmware");

  // attempt to connect to Wifi network:
  while ( status != WL_CONNECTED) {
    Serial.print("Attempting to connect to Network named: ");
    Serial.println(ssid);                   // print the network name (SSID);

    // Connect to WPA/WPA2 network. Change this line if using open or WEP network:
    status = WiFi.begin(ssid, pass);
    // wait 10 seconds for connection:
  server.begin();                           // start the web server on port 80
  printWifiStatus();                        // you're connected now, so print out the status

void loop() {
  WiFiClient client = server.available();   // listen for incoming clients

  if (client) {                             // if you get a client,
    Serial.println("new client");           // print a message out the serial port
    String currentLine = "";                // make a String to hold incoming data from the client
    while (client.connected()) {            // loop while the client's connected
      if (client.available()) {             // if there's bytes to read from the client,
        char c = client.read();             // read a byte, then
        Serial.write(c);                    // print it out the serial monitor
        if (c == '\n') {                    // if the byte is a newline character

          // if the current line is blank, you got two newline characters in a row.
          // that's the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
            // and a content-type so the client knows what's coming, then a blank line:
            client.println("HTTP/1.1 200 OK");

            // the content of the HTTP response follows the header:
            client.print("Click <a href=\"/H\">here</a> turn the LED on pin 9 on<br>");
            client.print("Click <a href=\"/L\">here</a> turn the LED on pin 9 off<br>");

            // The HTTP response ends with another blank line:
            // break out of the while loop:
          else {      // if you got a newline, then clear currentLine:
            currentLine = "";
        else if (c != '\r') {    // if you got anything else but a carriage return character,
          currentLine += c;      // add it to the end of the currentLine

        // Check to see if the client request was "GET /H" or "GET /L":
        if (currentLine.endsWith("GET /H")) {
          digitalWrite(13, HIGH);               // GET /H turns the LED on
        if (currentLine.endsWith("GET /L")) {
          digitalWrite(13, LOW);                // GET /L turns the LED off
    // close the connection:
    Serial.println("client disonnected");

void printWifiStatus() {
  // print the SSID of the network you're attached to:
  Serial.print("SSID: ");

  // print your WiFi shield's IP address:
  IPAddress ip = WiFi.localIP();
  Serial.print("IP Address: ");

  // print the received signal strength:
  long rssi = WiFi.RSSI();
  Serial.print("signal strength (RSSI):");
  Serial.println(" dBm");
  // print where to go in a browser:
  Serial.print("To see this page in action, open a browser to http://");

void printDirectory(File dir, int numTabs) {
  while (true) {

    File entry =  dir.openNextFile();
    if (! entry) {
      // no more files
    for (uint8_t i = 0; i < numTabs; i++) {
    if (entry.isDirectory()) {
      printDirectory(entry, numTabs + 1);
    } else {
      // files have sizes, directories do not
      Serial.println(entry.size(), DEC);

and the monitor says:

Initializing SD card...initialization done.
TI-01-06.CSV      26277
2015TELE.CSV      110
TI-01-07.CSV      61222
TI-01-10.CSV      61454
TI-01-11.CSV      61246
TI-01-12.CSV      61877
TI-01-13.CSV      24391
TI-01-08.CSV      61241
TI-01-09.CSV      61571
   INDEXE~1      76
2015TELE.CS1      185
INDEX.HTM      13337
Please upgrade the firmware
Attempting to connect to Network named: dlink
Attempting to connect to Network named: dlink

If i comment the line "if (!SD.begin(chipSelect)) {" to "  Serial.println("done!");", the Wifi works well.
The shield is updates at V 1.1.0

Can any help me, making a webserver with this bug are not cool...


Jan 26, 2015, 10:32 pm Last Edit: Jan 26, 2015, 10:34 pm by SurferTim
What IDE version are you using?

Please upgrade the firmware
The firmware is not upgraded to v1.1.0.

You can check. Try printing the firmware version.
Code: [Select]
String fv = WiFi.firmwareVersion();
  if ( fv != "1.1.0" )
    Serial.println("Please upgrade the firmware");

// add this
Serial.print(F("Firmware version: "));



I have a Mega 2560 (not R3) with a wifi shield (R3), and your sketch works with IDE versions 1.0.6 and 1.5.8. Maybe someone else will test it with an Uno R3.


I have also a mega and have the same pb.
In all cases, Wifi works fine alone, Sd also alone, but both don't works.
I have not the firmware message with wifi alone.
Can it be the shield has a preoblem?


I have also a mega and have the same pb.
In all cases, Wifi works fine alone, Sd also alone, but both don't works.
I have not the firmware message with wifi alone.
Can it be the shield has a preoblem?
Could be the shield or the SD card. I tested this with my setup and it worked fine. ??


It was the SD card!!
That was a 32 GB Samsung .
The new is a 8 GB Intenso.
Is there a reason?

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