IntermediateFarms
How to build an automatic sugar cane farm in Minecraft
Above each piston, place an Observer whose face looks at the spot of the third cane block (layer 7).
×8 Tested 26.3 The Observer watches the block in front of it and sends a short redstone pulse from its back whenever that block changes. It is the heart of most automatic farms.
It is made with the Crafting Table from 6 × Cobblestone, Nether Quartz and 2 × Redstone Dust. It is mined with a pickaxe.
What it does
The face looks at one block; the red dot on the back is the output. Placing or breaking that block, a crop growing, a door opening or a furnace lighting up all trigger the Observer, which emits a pulse of full strength for a very short time.
Point one at sugar cane, a pumpkin stem or bamboo and wire it to a piston, and the farm harvests itself when the plant grows. Two Observers facing each other create a fast clock.
Together with Slime Blocks and pistons, Observers are used to build flying machines that move on their own.
How to craft
Crafting table 
6 × Cobblestone + 2 × Redstone Dust + Nether Quartz → Observer
// Slots with several items cycle through every accepted option.
Tutorials with Observer (2)
×8 Tested 26.3 BeginnerRedstone
Redstone basics in Minecraft: dust, repeater, comparator, observer
Repeaters boost and delay it, comparators compare it and read containers, observers create pulses.
×1 Tested 26.3 Block states
| facing | north · east · south · west · up · down |
|---|---|
| powered | true · false |
Tags
#minecraft:blocks_dolphin_jump#minecraft:blocks_fluid_flow#minecraft:blocks_lava_fire_spread#minecraft:blocks_motion#minecraft:blocks_motion_in_heightmap#minecraft:blocks_motion_in_heightmap_no_leaves#minecraft:blocks_motion_no_leaves#minecraft:causes_suffocation#minecraft:entities_can_teleport_to#minecraft:ice_melts_when_destroyed_above#minecraft:mineable/pickaxe#minecraft:sulfur_cube_swallowable
Observer · FAQ
How do you get Observer in Minecraft?
At the Crafting Table: 6 × Cobblestone, 1 × Nether Quartz and 2 × Redstone Dust give 1 × Observer. Mining the block drops it.
What is Observer used for in Minecraft?
It detects changes to the block it faces and sends a short redstone pulse, which is ideal for automatic farms.
What tool do you need to mine Observer?
The fastest tool is the pickaxe.
What sound does a note block make on Observer?
Placed under a Note Block, Observer gives the Bass drum sound.