minecraft-java-editionminecraft-redstone
I want to know how the AFK fish farm works.
I know that the hopper carries the fished item into the chest, and that the trapdoor is opened by the pressure plate.
But, I would like to know how the fish farm reels in the fishing rod at the right time.
I'm just trying to get better at redstone, and I thought this was important to know.
Anyway, if anyone can help, I would really appreciate it!
This setup works:
One of your items is an arrow, the other is any non-dispensing item like redstone.
Arrows will fire and miss the tripwire. Items will hit it then burn up, triggering a signal. You can use the items you suggested: arrow, cobble, cobble, arrow and the desired signal will be generated (well, the inverse).
A hit with a snowball can summon a reinforcement zombie.
Just tested with the following setup: 1.6.2, creative, hard, clean superflat world, time 23000, daylight cycle off. Time 23000 prevents both natural spawning and sun damage.
It can take quite some time to get a spawn, though. Wiki mentions 80 x 80 x 80 spawning area. If this is a randomly picked point, the probability is 1/80 per hit on unobstructed superflat, and it definitely is somewhere in that order of magnitude by my testing. Not worth it for farming improvement, I'd say.
Best Answer
Fish farms use a carefully balanced system of blocks. The water that you look at is at exactly the right level that the fishing bobber just barely triggers a tripwire above the water. When a fish bites, the bobber not only visually moves down, it actually does move downwards and un-triggers the tripwire.
That opens the trapdoor that is otherwise closed in front of you, making your constant clicks no longer be trapdoor clicks, but instead fishing rod clicks, so you reel it in, which automatically catches the fish, and cast it out again, which triggers the tripwire again.
Note that this type of farm no longer produces overpowered end-game loot in 1.16, because there you need to actually fish in open water to be able to catch treasure loot. You can still get tons of fish with the classic fish farms, you can still get treasure loot from fishing manually and you can still get all kinds of loot in newly designed "open water" fish farms, but those do not use tripwires, so they are very slow (all intended for game balancing). Getting over-powered end-game items is also still possible, by actually proceeding in and playing the game normally.