Sorry, I forgot the sainsmart 3.3 - 5 v switch. It must be at 5 v.
The SeedStudio ethernet (the one i bought from Radio Shack) wont initialize!!
The newer ethernet shields from Radio Shack have the w5200 ethernet controller onboard. Is it this one?http://www.seeedstudio.com/wiki/Ethernet_Shield_V2.0If so, you must download and install the Ethernet Shield V2.0 library for that controller from that page.
I use a w5100 shield and Mega 2560, and my server code with a SD works great.http://playground.arduino.cc/Code/WebServerSTYou can do me a favor and try it with your w5200. Insure you change the includes as specified for the w5200. Let me know if it works ok.
// change this Ethernet.begin(mac, ip, gateway, subnet);// to this Ethernet.begin(mac, ip, gateway, gateway, subnet);
// charge this card.init(SPI_FULL_SPEED, 4);// to this card.init(SPI_HALF_SPEED, 4);
// add this digitalWrite(4,HIGH); Ethernet.begin(mac, ip, gateway, gateway, subnet);
// change this card.init(SPI_FULL_SPEED, 4);// to this card.init(SPI_HALF_SPEED, 4);
I attached the new w5200.h file and the test sketch. Go to "My Documents/Arduino/libraries/EthernetV2_0/utility" folder. Rename the current w5200.h file to w5200orig.h. Then move this w5200.h file into that folder.Then compile and upload the DHCPAddressPrinterW5200.ino sketch.It should report "interface up" or "interface down", depending on the CAT5 cable. If you leave it inserted, it should report "interface up". If you remove it, it should report "interface down".Thanks for testing this for me. I'm looking forward to getting a w5200 shield soon.
Serial.println("Starting....");byte linkStatus = W5100.getPHYStatus(); Serial.println(linkStatus); if(linkStatus & 0x20) Serial.println("interface up");else Serial.println("interface down");