There's nothing special about ground, it's the same as a digital pin set to low (from an M/C perspective). You don't need to have two separate grids. Just try o

There's nothing special about ground, it's the same as a digital pin set to low (from an M/C perspective). You don't need to have two separate grids. Just try out combinations of pins as data/power and ground until you get a set that works and float (disconnect/set as input) the others.