If you watch at about 2:50, you can see most of the left half of the circuit. The part for the stairs looks like it isn't shown very well but that is less important timing wise. Watch carefully over and over and see if you can replicate it this way. It looks like the repeaters for the middle activate and deactivate immediately. So the order (from a circuit standpoint) for both directions is M, L+R. This works for closing because the middle repeaters don't have anything to activate until the blocks are pushed into the middle. When opening, they will retract the middle immediately.
Breaking it down:
Opening
- Middle repeaters deactivate (middle pistons retract)
- Delay
- Left and Right redstones deactivate (left and right pistons retract)
Closing
- Middle repeaters activate (nothing happens because the middle pistons are not in position)
- Delay
- Left and Right redstones activate (left and right pistons extend)
- Now the middle pistons have been pushed into position and are activated by the middle repeaters
I don't know the definition of tree miller...
[EDIT: as the video I linked to disappeared, thank Robotnik for pointing this out]
But there are a variety of semi-automated tree harvesters out there that are capable of a modest amount of AFK.
The idea is for you to have saplings in your hand, plant one, have a bone meal dispsenser adjacent, which bone meals the sapling.
Once the sapling grows into a tree, a large redstone device, which surrounds a 5x5 area pushes the logs out to a large wood collection area.
If you are daring, you can build an enclosure for a wither, and have the wither blow up the wood, most of which will get harvested.
Saplings are collected in hoppers at the bottom, and moved back to you, so you just have to sit and plant saplings.
There are many tutorials on the topics, in particular, google: Minecraft automatic tree farm (or minecraft AFK tree farm). A video from a more famous youtuber than previously posted is here:
Best Answer
There are a number of methods for extending a redstone signal:
Repeaters
Just plonk down repeaters. Each one gives you another 15 blocks, however, there is a 1-tick delay in the signal for each repeater you use, which can slow down large circuits.
Instant Wire
This allows for instantaneous redstone transmission over long distances. There's a wiki page for it! It's a little complex, so here's video:
Should the video go down, a search for Instant Wire will turn up many more.
Mods
MineFactory Reloaded has redstone wiring that can extend for supposedly unlimited distance, preserving signal strength, using a network system.