The Wandboard blockdiagram explains clearly which signals are being used and how they are routed from the System-on-Module (SoM) towards the EDM connector that comes down to the I/O shield which holds all the physical connectors such as the HDMI, LAN, USB and so forth.

To give you all a short update : We are working around the clock to have software and documentation in a shape that is easy to understand for beginning engineers and at the same time not annoying experienced engineers. It’s a tough challenge given that we want to have Wandboards in people’s hand before the end of the year.