by Ari Dor
1. Piston & Sticky Piston
Pistons and sticky pistons push and pull blocks. Pistons push blocks when powered, and sticky pistons push when powered and and pull when depowered9,10,11,. Pistons canât push more than 12 blocks, and if they are powered when more than 12 blocks are in front of them, they wonât do anything. This also applies to sticky pistons. When a sticky piston pushes more than 1 block and gets depowered, it will only retract 1 block. This is where slime blocks and honey blocks come in: they are the only âstickyâ blocks in the game. They allow for more blocks to be retracted at once12,13.
Observers14, well, observe. If something somehow changes directly in front of it, it will send a quick redstone output behind it. It is most commonly used in automatic farming, to detect when a plant has reached a certain height and is therefore ready for harvest15.