Step 2: Connect the Piston Activators with Redstone

Dig a two deep trench connecting the redstone torches on each side of your piston set up.

 Remove a block underneath the block that your redstone torches sit on. Do this on either side.

Place a redstone torch. You will see that the top redstone torch deactivates.

Dig three blocks out from the torch you just placed and run redstone wire to a third torch.

Connect these third torches with redstone wire as seen above. This will ensure the piston arrays communicate with each other when activated.