As mentioned in title i have a problem connecting my arduino to the server using ethernet shield. I tried multiple examples aswell as mine program but either of those failed to connect. If i print client.connect(server,80); it prints -5.
I am stuck for awhile now and i would appreciate some help.
Thank you.
Post your code. Remember to use code tags !
Ok i found an error in my code...
instead of connecting to lets say "www.google.com" i was connecting to "www.google.com/".
But after i corrected that it still didn't connect, so i tried printing the return value of client.connect("www.google.com", 80), without commenting the rest of the code :
if (client.connect(server, 80)) {
Serial.println("connected");
// Make a HTTP request:
client.println("GET /search?q=arduino HTTP/1.1");
client.println("Host: www.google.com");
client.println("Connection: close");
client.println();
}
else {
Serial.println("connection failed");
}
so it looks like i have to run client.connect(server, 80) twice in order to get it connected. Any idea why?
Thank you
Your problem may be in the part of the code you don't show.
so it looks like i have to run client.connect(server, 80) twice in order to get it connected. Any idea why?
After your Ethernet.begin() call in setup, add a two second delay. Works for me.
Ethernet.begin(mac, ip, dnServer, gateway, netmask);
delay(2000);
Here's the code... it is an example for WebCliend in Ethernet library.
I previously tried to wait before client.connect() for about 10 seconds, and i tried now with 2 seconds delay but it still wont connect, except if u put client.connect() two times in my code.
/*
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
by David A. Mellis
modified 9 Apr 2012
by Tom Igoe, based on work by Adrian McEwen
*/
#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, 0x83, 0x9D };
// if you don't want to use DNS (and reduce your sketch size)
// use the numeric IP instead of the name for the server:
//IPAddress server(74,125,232,128); // numeric IP for Google (no DNS)
char server[] = "www.google.com"; // name address for Google (using DNS)
// Set the static IP address to use if the DHCP fails to assign
IPAddress ip(192,168,0,177);
// 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:
// try to congifure using IP address instead of DHCP:
Ethernet.begin(mac, ip);
}
// give the Ethernet shield a second to initialize:
delay(1000);
Serial.println("connecting...");
// 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/1.1");
client.println("Host: www.google.com");
client.println("Connection: close");
client.println();
}
else {
// kf you didn't get a connection to the server:
Serial.println("connection failed");
}
}
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:
while(true);
}
}
What ethernet shield you use ? Wiznet 5100 ? What's your router's LAN IP ? Did you try using static IPs , not DNS ?
Simple client test code you can try.
//zoomkat 9-22-12
//simple client test
//for use with IDE 1.0.1
//with DNS, DHCP, and Host
//open serial monitor and send an e to test
//for use with W5100 based ethernet shields
//remove SD card if inserted
#include <SPI.h>
#include <Ethernet.h>
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
char serverName[] = "web.comporium.net"; // zoomkat's test web page server
EthernetClient client;
//////////////////////
void setup(){
if (Ethernet.begin(mac) == 0) {
Serial.println("Failed to configure Ethernet using DHCP");
// no point in carrying on, so do nothing forevermore:
while(true);
}
Serial.begin(9600);
Serial.println("Better client test 9/22/12"); // so I can keep track of what is loaded
Serial.println("Send an e in serial monitor to test"); // what to do to test
}
void loop(){
// check for serial input
if (Serial.available() > 0) //if something in serial buffer
{
byte inChar; // sets inChar as a byte
inChar = Serial.read(); //gets byte from buffer
if(inChar == 'e') // checks to see byte is an e
{
sendGET(); // call sendGET function below when byte is an e
}
}
}
//////////////////////////
void sendGET() //client function to send/receive GET request data.
{
if (client.connect(serverName, 80)) { //starts client connection, checks for connection
Serial.println("connected");
client.println("GET /~shb/arduino.txt HTTP/1.1"); //download text
client.println("Host: web.comporium.net");
client.println("Connection: close"); //close 1.1 persistent connection
client.println(); //end of get request
}
else {
Serial.println("connection failed"); //error message if no client connect
Serial.println();
}
while(client.connected() && !client.available()) delay(1); //waits for data
while (client.connected() || client.available()) { //connected or data available
char c = client.read(); //gets byte from ethernet buffer
Serial.print(c); //prints byte to serial monitor
}
Serial.println();
Serial.println("disconnecting.");
Serial.println("==================");
Serial.println();
client.stop(); //stop client
}
If client.connect() returns -5, then that is caused by a DNS error (invalid response). This is from the ProcessResponse function in Dns.cpp.
// Check for any errors in the response (or in our request)
// although we don't do anything to get round these
if ( (header_flags & TRUNCATION_FLAG) || (header_flags & RESP_MASK) )
{
// Mark the entire packet as read
iUdp.flush();
return -5; //INVALID_RESPONSE;
}