I have a project with an arduino UNO, a proto shield with some electronics on it and the official ethernet shield.
The ethernet functions work only when the ethernet shield is directly stacked on top of the arduino. When the protoshield is stacked between the arduino and the ethernet shield, I can't connect it to ethernet, I can't ping, I cant post data... nada!
I have a problem with this too. I got an Mega with and ethershield that uses the 10-13 pins, but also the ICSP header.
can someone explain me this? what is the really useful pins? the header on the right ( with the 6 pins) or the 10-13 pins? or, in my case, on the MEGA, should I use the 10-13 or the 50-53 or even the 50-52 and leave the 10 put?
this is driving me nuts, because I cannot figure out how have worked in the past and is sort of random...