W5100 送電後不會運作，要手按 RESET

[yehlu]

https://www.youtube.com/watch?v=9ZBeprOqC3w

http://forum.arduino.cc/index.php?topic=28175.15

dentified an issue with various W5100 (Wiznet) clone Ethernet shields - the issue is that upon applying power to the Arduino, the Ethernet shield doesn't initialise unless you press the reset button. Tried various solutions including adding a delay before Ethernet.Begin() but didn't work. After pulling out the oscilloscope I discovered that the Ethernet board was not being reset because the reset pin wasn't held low long enough - initially butchered the board and added code to manually pull the W5100 reset pin low, but found a much simpler, more elegant solution - Add a 0.1uf (100nF) capacitor between the pins on the reset switch. Works well for me. Inspired by these posts - http://forum.arduino.cc/index.php?top...