[SOLVED] Arduino Uno R2 and Wiznet 5100. DHCP does not work.

Projects Networking, Protocols, and Devices
3

Try this sketch. It tests the SPI connection from the Arduino to the shield.

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

byte mac[] = {  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192,168,2,2);

void setup() {
  Serial.begin(9600);

  // disable SD card if one in the slot
  pinMode(4,OUTPUT);
  digitalWrite(4,HIGH);

  Serial.println("Starting w5100");
  Ethernet.begin(mac,ip);

  Serial.println(Ethernet.localIP());
}

void loop() {
}

If the serial monitor displays 192.168.2.2, then that part works. If it displays any other value, like 0.0.0.0, then the SPI connection failed.