I'm banging my head against the wall trying to google this one... I'm sure this has come up before and been answered before, but I just can't find the information I need.
I'm using 2 shields (Sparkfun CAN shield & official WiFi shield), that appear to both be using the same 'handshake' pin (pin 7). This appears to be separate from the SS pin used for SPI communication. Both shields have documentation which basically reads: 'Digital pin 7 is used as a handshake pin, and should not be used'. I've got the 2 shields isolated and connected with a mess of jumper wires, and I can use either as long as I disconnect the other from pin 7, so I'm pretty sure that's where my conflict is.
So here are my questions: What is the handshake pin, what is it used for, and where is it defined so I can change it? I'd prefer to change it on the CAN shield and leave the wifi alone, but either way can work. I've looked through the .h and .c files for the CAN shield library, with no luck. I'm not sure where to find the WiFi library files (built in lib). Since I'm not quite sure how a handshake pin is used, I'm not sure exactly what I'm looking for in those files.