I am using an arduino mega 2560 + ethernet shield. It is working fine from a network point of view. But I noticed that DIGITAL PIN 51 is always HIGH. Even if I write it low.
I read that such pin 51 is used for SPI communication. Does it explain the HIGH level on pin 51 ? Is there a workaround ?
Thanks for your answer.
You must leave pins 50-53 alone. Those are used by the SPI bus.