I thought it would take an hour to make all the custom cables I need to connect the shield to the front panel, RJ45 jack, etc. Luckily I started with the RJ45 jack cable so I could test the boards. I needed to crimp a connector onto each wire and slide them into the female connector header. But the magic crimping tool ain’t so magic after all, and it takes a lot of finessing to get a clean crimp that will slide and snap into the connector properly.
The cable carries the two TX/RX signals for the Hand Controllers to two RJ45 jacks.
Rather than spend the rest of the night making the other cables I plugged the Mega and a Hand Controller together, powered them up and it worked! The Hand Controller sent a steady stream of accelerometer data to the Mega.
I am NOT looking forward to more cable making.