WiFi101 - WiFi.beginProvision()


Initializes the WiFi101 library’s in provision mode. This mode implements the behaviour needed to connect the board to known APs or to select new ones if nothing known can be reached.

When called, the function will try to connect to a previously associated access point. If this fails, an access point named “wifi101-XXXX” will be created, where XXXX are the last 4 digits of the boards MAC address. You need to connect to the access point created, then visit http://wifi101/ and configure an SSID and password of an AP within reach. When the new association is done, the next connection will be to that AP.




channel: optional parameter, to specify channel to use for provisioning mode, channel 1 will be used by default


WL_CONNECTED when connected to a network WL_PROVISIONING when connecting to previously associated access point fails


  WiFi Web Server

  A simple web server that shows the value of the analog input pins.
  using a WiFi 101 Shield.

  This example is written to configure the WiFi settings using provisioning mode.
  It also sets up an mDNS server so the IP address of the board doesn't have to
  be obtained via the serial monitor.

   WiFi 101 Shield attached
   Analog inputs attached to pins A0 through A5 (optional)

  created 13 July 2010
  by dlf (Metodo2 srl)
  modified 31 May 2012
  by Tom Igoe


#include <SPI.h>
#include <WiFi101.h>
#include <WiFiMDNSResponder.h>

const int ledPin = 6; // LED pin for connectivity status indicator

char mdnsName[] = "wifi101"; // the MDNS name that the board will respond to
                             // after WiFi settings have been provisioned
// Note that the actual MDNS name will have '.local' after
// the name above, so "wifi101" will be accessible on
// the MDNS name "wifi101.local".

WiFiServer server(80);

// Create a MDNS responder to listen and respond to MDNS name requests.
WiFiMDNSResponder mdnsResponder;

void setup() {
  //Initialize serial:

  // check for the presence of the shield:
  if (WiFi.status() == WL_NO_SHIELD) {
    Serial.println("WiFi 101 Shield not present");
    // don't continue:
    while (true);

  // configure the LED pin for output mode
  pinMode(ledPin, OUTPUT);

  // Start in provisioning mode:
  //  1) This will try to connect to a previously associated access point.
  //  2) If this fails, an access point named "wifi101-XXXX" will be created, where XXXX
  //     is the last 4 digits of the boards MAC address. Once you are connected to the access point,
  //     you can configure an SSID and password by visiting http://wifi101/

  while (WiFi.status() != WL_CONNECTED) {
    // wait while not connected

    // blink the led to show an unconnected status
    digitalWrite(ledPin, HIGH);
    digitalWrite(ledPin, LOW);

  // connected, make the LED stay on
  digitalWrite(ledPin, HIGH);


  // Setup the MDNS responder to listen to the configured name.
  // NOTE: You _must_ call this _after_ connecting to the WiFi network and
  // being assigned an IP address.
  if (!mdnsResponder.begin(mdnsName)) {
    Serial.println("Failed to start MDNS responder!");

  Serial.print("Server listening at http://");

  // you're connected now, so print out the status:

void loop() {
  // Call the update() function on the MDNS responder every loop iteration to
  // make sure it can detect and respond to name requests.

  // listen for incoming clients
  WiFiClient client = server.available();
  if (client) {
    Serial.println("new client");
    // an HTTP request ends with a blank line
    bool currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        // if you've gotten to the end of the line (received a newline
        // character) and the line is blank, the HTTP request has ended,
        // so you can send a reply
        if (c == '\n' && currentLineIsBlank) {
          // send a standard HTTP response header
          client.println("HTTP/1.1 200 OK");
          client.println("Content-Type: text/html");
          client.println("Connection: close");  // the connection will be closed after completion of the response
          client.println("Refresh: 5");  // refresh the page automatically every 5 sec
          client.println("<!DOCTYPE HTML>");
          // output the value of each analog input pin
          for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
            int sensorReading = analogRead(analogChannel);
            client.print("analog input ");
            client.print(" is ");
            client.println("<br />");
        if (c == '\n') {
          // you're starting a new line
          currentLineIsBlank = true;
        else if (c != '\r') {
          // you've gotten a character on the current line
          currentLineIsBlank = false;
    // give the web browser time to receive the data

    // close the connection:
    Serial.println("client disconnected");

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

  // print your WiFi 101 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");