Ethernet Client.connect() returns error code -5

Projects Programming
1

I have googled and searched these forums and cannot find any reference of my error code.

If I wait for "client" to return true, the program waits forever (from http://arduino.cc/en/Reference/IfEthernetClient)

while(!client){
;
}

If I skip that and try to connect anyway, I get a connection result of -5.

int ret = client.connect(serverName, 6990);
if (ret == 1) {
Serial.println("Connected");
client.println("GET /index.html");
client.println();
}
else {
Serial.println("Failed to connect ");
Serial.println(ret);
Serial.println(client.status());
}

Does anyone know what that error code means? Is the shield bunk? Is it a PIN conflict, I am very new to arduino, but have tried many examples and they all seem to have the same result.

My Router shows the MAC and hostname with a valid lease:
90:a2:da:0d:4e:71 192.168.000.007 255.255.255.000 D:00 H:08 M:53 S:20 Sat Sep 08 04:37:11 2012 WIZnet0D4E71

/*
  Web client
 
 This sketch connects to a website (http://www.google.com)
 using an Arduino Wiznet Ethernet shield. 
 
 Circuit:
 * Ethernet shield attached to pins 10, 11, 12, 13
 
 created 18 Dec 2009
 modified 9 Apr 2012
 by David A. Mellis
 
 */

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

// Enter a MAC address for your controller below.
// Newer Ethernet shields have a MAC address printed on a sticker on the shield

byte mac[] = {0x90, 0xA2, 0xDA, 0x0D, 0x4E, 0x71 };;
IPAddress server(173,194,33,104); // Google

// Initialize the Ethernet client library
// with the IP address and port of the server 
// that you want to connect to (port 80 is default for HTTP):
EthernetClient client;

void setup() {
 // Open serial communications and wait for port to open:
  Serial.begin(9600);
   while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }

  // start the Ethernet connection:
  if (Ethernet.begin(mac) == 0) {
    Serial.println("Failed to configure Ethernet using DHCP");
    // no point in carrying on, so do nothing forevermore:
    for(;;)
      ;
  }
  // give the Ethernet shield a second to initialize:
  delay(1000);
  Serial.println("connecting...");
 
    Serial.println("Obtaining local IP");
    IPAddress myIPAddress = Ethernet.localIP(); 
    Serial.println(myIPAddress);
  // if you get a connection, report back via serial:
  if (client.connect(server, 80)) {
    Serial.println("connected");
    // Make a HTTP request:
    client.println("GET /search?q=arduino HTTP/1.0");
    client.println();
  } 
  else {
    // kf you didn't get a connection to the server:
    Serial.println("connection failed");
    Serial.println(ret);
    Serial.println(client.status());
  }
}

void loop()
{
  // if there are incoming bytes available 
  // from the server, read them and print them:
  if (client.available()) {
    char c = client.read();
    Serial.print(c);
  }

  // if the server's disconnected, stop the client:
  if (!client.connected()) {
    Serial.println();
    Serial.println("disconnecting.");
    client.stop();

    // do nothing forevermore:
    for(;;)
      ;
  }
}

result:

connecting...
Obtaining local IP 
192.168.0.7
connection failed
-5
0

disconnecting.
2

I'm not clear what those two bits of code are - the first fragment seems completely different to the second one. The examples connect to a specified IP address. Have you tried doing that? And I suggest you ensure it's a local IP address not something out on the internet, just to eliminate any wide area network issues. I guess that the first code fragment is connecting to a server specified by hostname and that relies on DNS working, which is an extra layer of complexity. Hard-code the IP address for a test as shown in the second example for a better chance of success.

3

Thanks for your response. Sorry is the snippets don't line up, I have been trying all sortts of examples and custom code.

Anyway it seems the solution was to add a delay between the Serial.begin() and Ethernet.begin(), as well as increasing the delay before using client.connect().

However even though I can now pull back google.com using the hostname, while(!client){} will still cause the program to hold indefinitely... So that is why I just went with a 5 second delay after Ethernet.begin().

/*
  Web client

 This sketch connects to a website (http://www.google.com)
 using an Arduino Wiznet Ethernet shield. 

 Circuit:
 * Ethernet shield attached to pins 10, 11, 12, 13

 created 18 Dec 2009
 modified 9 Apr 2012
 by David A. Mellis

 */

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

// Enter a MAC address for your controller below.
// Newer Ethernet shields have a MAC address printed on a sticker on the shield

byte mac[] = {0x90, 0xA2, 0xDA, 0x0D, 0x4E, 0x71 };;
char server[] = "google.com"; // Google

// Initialize the Ethernet client library
// with the IP address and port of the server 
// that you want to connect to (port 80 is default for HTTP):
EthernetClient client;

void setup() {
 // Open serial communications and wait for port to open:
  Serial.begin(9600);
   while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }
delay(5000);
  // start the Ethernet connection:
  if (Ethernet.begin(mac) == 0) {
    Serial.println("Failed to configure Ethernet using DHCP");
    // no point in carrying on, so do nothing forevermore:
    for(;;)
      ;
  }
  // give the Ethernet shield a second to initialize:
  delay(5000);
  Serial.println("connecting...");

    Serial.println("Obtaining local IP");
    IPAddress myIPAddress = Ethernet.localIP(); 
    Serial.println(myIPAddress);
  // if you get a connection, report back via serial:
  int ret = client.connect(server, 80);
  if (ret == 1) {
    Serial.println("connected");
    // Make a HTTP request:
    client.println("GET /search?q=arduino HTTP/1.0");
    client.println();
  } 
  else {
    // kf you didn't get a connection to the server:
    Serial.println("connection failed");
    Serial.println(ret);
    Serial.println(client.status());
  }
}

void loop()
{
  // if there are incoming bytes available 
  // from the server, read them and print them:
  if (client.available()) {
    char c = client.read();
    Serial.print(c);
  }

  // if the server's disconnected, stop the client:
  if (!client.connected()) {
    Serial.println();
    Serial.println("disconnecting.");
    client.stop();

    // do nothing forevermore:
    for(;;)
      ;
  }
}