There are a lot of repeater here, but really it is all basic redstone. I will guide you through it.
It starts here:
That redstone torch is the start of the chain that kickstarts the entire thing. When the tree grows the sapling over there turns into a log, and the powered repeater powers that log which then powers the other repeater and here this signal is split into three. for easier understanding lets name them: downsignal, longsignal going to the left and shortsignal going to the right.
Longsinal branches a little and frees a servo that will go down and get some sand.
Before downsignal is on, here are the pictures of the floor below:
Downsginal is on the block above the far left torch (there is a slab above that torch).
Shortsignal deactivates a Pressurizer (which is a thing that sucks itens). For now ignore that parasieve and comparator.
Two comments here. First, there is a reason why I need to deactivate it. Second, I could have done this differently, with a servo going around the edges. Maybe I'll do it at a later date.
The servo will go up to the ceiling and go in a loop here:
it will place a sand block under the piston then activate a redstone pulse that will activate said piston.
The servo will continue this loop until it has no sand left in its inventory when it then will go down again.
Longsignal just pretty much loops around...
...and goes to a AND gate, althought why will be made clearer later. that signal ends at the robotic arm, which is the thing that will plant the sapling back and something else.
The sand will push down the logs until it reaches the lacerator down on the second floor where these wil get harvested. When the last log is gone the sand will fall down onto a torch with a hopper bellow which will put all the sand back in the pick up place for the servo. One thing to be carefull about is that the the pressurizer, if set to a strong enough setting can pull the falling sand slightly and scew up your system.
The delay is timed so that after all the sand fell, the pistons will put the dirt block back right before the robotic arm recieves a signal for planting the sapling.
Now let's go back to the parasieve. (If you don't know about the parasieve, click
here)
So here is the deal. On the parasieve you will put sapling like this:
This configuration changes how the comparator sees the inventory. In this way the comparator will put out a 15 strong signal if there are 3 or more saplings in that inventory. This is a great and amazing feature of the parasieves. I can set it up so it will do this with any amount up to a stack.
Anyway that signal is brought down...
...where is gets picked up by another comparator as well as a repeater:
This image is showing that if the signal coming down isn't 13 or higher that comparator won't output a redstone signal.
If that was the case than this clock wouldn't be running ( I changed this part a little from the video, just for pictures sake).
(clock desing picked from thejims on youtube)
However I can also deactivate the clock with a lever.
The end of the clock is hooked to the AND gate.
And if I do this:
Than I can aply bonemeal to the saplings
