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Topic: Setting up web client to local server on Mac OSX (direct connection) (Read 1 time) previous topic - next topic


Hi there,

I have an Arduino Uno w. Ethernet Shield running a slightly modified version of the demo WebClient sketch. I am wanting to connect to a server running locally on my macbook (running Mountain Lion), which is what I am also connecting the ethernet cable to. I have been able to connect to the server using it's local IP address (The code below is what I have used to do this), which would be going through my home router. However, I would like to be able to connect to this server without any network connection at all (for easy demonstration purposes).

Note that I am using DHCP, but I don't require this. Although I can't seem to get DHCP working unless I have a network connection.

My feeling is I'll have to set up some kind of virtual gateway, but at this stage am a bit lost. I would appreciate a bit of direction.

Code: [Select]
  Web client

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

* 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[] = {  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress server(192,168,0,3); // 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:

   while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only

  // start the Ethernet connection:
  Serial.println("Setting up Ethernet");
  if (Ethernet.begin(mac) == 0) {
    Serial.println("Failed to configure Ethernet using DHCP");
    // no point in carrying on, so do nothing forevermore:
  // give the Ethernet shield a second to initialize:

  // if you get a connection, report back via serial:
  if (client.connect(server, 5000)) {
    // Make a HTTP request:
    client.println("GET /home HTTP/1.0");
  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();

  // if the server's disconnected, stop the client:
  if (!client.connected()) {

    // do nothing forevermore:



you need a crossover cable (or a hub/switch) and hard set the ip address on both the arduino and your computer

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