For the Ethernet shield R3, I'm not using the microSD and don't have a card in the slot. So can I use digital pin 4 in my sketch, or should I just set it as a HIGH OUTPUT and not use it?

Ethernet Shield - Can I use pin 4?

SurferTim September 6, 2012, 12:38pm 2

Yes. Pin 4 is only needed if there is a memory card in the slot.

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