Arduino WiFi default connection timeout?

Projects Networking, Protocols, and Devices
1

I created an application to control and Arduino Uno R3 wirelessly using an Arduino Wifi shield. In developing it I noticed that when I set the WiFi shield in server mode, it stops listening after about 10 seconds of inactivity, or after 10 seconds without a client connected to it. Does anybody know if this is the case and how to change this timeout? I wrote a small sketch to illustrate the problem.

echo_server.txt (2.54 KB)

2

I added the code so it can be viewed instead of downloaded:

/*
 Echo Server
 
 A simple server that distributes that echoes what the client sends.

 Circuit:
 Arduino UNO R3 + Arduino WiFi shield attached
 
 */

#include <SPI.h>
#include <WiFi.h>

char ssid[] = "MyNet"; //  your network SSID (name) 
char pass[] = "MyPassword";    // your network password (use for WPA, or use as key for WEP)
char buffer[100];             // Input buffer

int index = 0;            // index for input buffer

int status = WL_IDLE_STATUS;

WiFiServer server(23);

boolean alreadyConnected = false; // whether or not the client was connected previously

void setup() {
  //Initialize serial and wait for port to open:
  Serial.begin(9600); 
  
  // check for the presence of the shield:
  if (WiFi.status() == WL_NO_SHIELD) {
    Serial.println("WiFi shield not present"); 
    // don't continue:
    while(true);
  } 
  
  // attempt to connect to Wifi network:
  while ( status != WL_CONNECTED) { 
    Serial.print("Attempting to connect to SSID: ");
    Serial.println(ssid);
    // Connect to WPA/WPA2 network.     
    status = WiFi.begin(ssid, pass);

    // wait 10 seconds for connection:
    delay(10000);
  } 
  // start the server:
  server.begin();
  // connected now, print out the status:
  printWifiStatus();
  
  memset(buffer, '\0', sizeof(buffer));
  index = 0;
 }


void loop() {
  // wait for a new client:
  WiFiClient client = server.available();


  // when the client sends the first byte, say hello:
  if (client) {
    
    if (!alreadyConnected) {
      // clean out the input buffer:
      client.flush();    
      Serial.println("We have a new client");
      client.println("Hello, client!");
      client.flush();
      alreadyConnected = true;
    } 

    if (client.available() > 0) {
      
      // read a byte incoming from the client:
      char thisChar = client.read();
      if ((thisChar != '\n') 
       && (thisChar != '\r')
       && (index < sizeof(buffer))
       ) {
        buffer[index++] = thisChar;
      } 
      else {
        client.println(buffer);
        client.flush();
        Serial.println(buffer);
        memset(buffer, '\0', sizeof(buffer));
        index = 0;
      }
    }
  }
}


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

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

There is a defect reported that seems to be related to this: Google Code Archive - Long-term storage for Google Code Project Hosting.

Does anybody know how to get the source code of the WiFi library and how to build it? I googled it and couldn't find anything.

3

Libraries are supplied as source. They are compiled when you compile the sketch.

4

I did't know that and it didn' ocurred to me to check. Thanks for the info.