Go Down

Topic: Arduino Uno WiFi Rev2 hangs if WiFi connection disrupted (Read 4669 times) previous topic - next topic


I am having a similar problem running the SimpleWebServer example . Firmware version is 1.2.4

If I switch off my router, the programme hangs and will not reconnect when the router is back up unless I reset the Arduino.

I have tried the suggestions above, but the wifi status remains at 3 even when there is no router so the program continuosly loops and will not reconnect.

Most frustrating, any help much appreciated.

Code: [Select]


  created 25 Nov 2012
  by Tom Igoe
#include <SPI.h>
#include <WiFiNINA.h>

#include "arduino_secrets.h"
///////please enter your sensitive data in the Secret tab/arduino_secrets.h
char ssid[] = SECRET_SSID;        // your network SSID (name)
char pass[] = SECRET_PASS;    // your network password (use for WPA, or use as key for WEP)
int keyIndex = 0;                 // your network key Index number (needed only for WEP)

int status = WL_IDLE_STATUS;
WiFiServer server(80);
int x = 0;
void setup() {

  Serial.begin(9600);      // initialize serial communication
  pinMode(9, OUTPUT);      // set the LED pin mode

  // check for the WiFi module:
  if (WiFi.status() == WL_NO_MODULE) {
    Serial.println("Communication with WiFi module failed!");
    // don't continue
    while (true);

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

  createConnection ();

void loop() {

  Serial.print("Wifi Status at start of loop; ");
  Serial.println (status);

  if (status != WL_CONNECTED) {
  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

    // close the connection:
    Serial.println("client disconnected");
    x = x + 1;
    Serial.print ("Number of times through the loop: ");
    Serial.println (x);
    Serial.print ("Wifi Status at end of loop: ");
    Serial.println (status);
    if (status != WL_CONNECTED) {

  delay (1000);

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

  // print your board'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 createConnection() {
  // This new line is required to disconnect the previous connection otherwise
  // it will try to use the old connection and never reconnect if the connection fails
  status = WiFi.disconnect();

  while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to Network named: ");

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


I have found a way round this by checking the WiFi strength, if the router drops out this goes down to 0.

This is the bit of code that checks the signal and restarts the sketch if the router has dropped out.

Code: [Select]

 void(* resetFunc) (void) = 0;//declare reset function at address 0

void loop() {

  if (WiFi.RSSI() == 0) // Checks if Wifi signal lost.
  { resetFunc(); //Calls Reset

//rest of code goes here.


Go Up