REDSTONEPEDIA › Circuits › Automatic doors
Automatic door: opens as you walk up, closes behind you (2×2 piston door)
opens as you walk up, closes behind you · 42 blocks · no waiting, even sprinting
A 2×2 piston door that opens by itself when you walk up from either side and closes behind you, even when two people walk through close together. Stand still in the doorway and the door closes on you and hurts you (half a heart per hurt) until you step out.
it closes 1.35 s after you pass · fits in 8×5×3
Try it
The view shows the door as built: the browser's simulator has no walkers to open it. In the game, walk up to it from either side: it opens before you reach it, even at a sprint, and closes once you have passed. Walk on through: if you stop in the doorway, it closes on you.
How this design does it: Opens as you walk up, closes behind you, from either side: a stone plate in front of and behind each door column, any of them opening the whole door, their supports wired under the floor into the torches that hold classic6's pistons closed; each torch sits beside its bottom piston and powers the top one through the stone above it.
Build it
Download .litematic Download the design as text
The .litematic opens in Litematica (Minecraft 26.3): every block of the design in one region. The text file is the same build written as plain text, block by block.
Put its plates where mobs can't walk: a mob on a plate opens it too.
Blocks used: redstone torch redstone wire smooth stone sticky piston stone stone pressure plate
Which to build: this door takes 42 blocks and opens before you reach it, even at a sprint, but it closes on anyone who stops in the doorway. For a door that also stays open for someone standing in the doorway: Automatic door: opens as you walk up, closes behind you · 91 blocks · you wait up to 0.65 s at the door. If the entrance doesn't need to be hidden, two iron doors with pressure plates do the job in about 10 blocks.
Details: how it works, measurements and properties
In depth
A 2×2 piston door: four sticky pistons pull the four door blocks into the wall. Its detectors lie in the walkway on both sides of the door, where you step anyway: stone pressure plates, which feel players and mobs but never dropped items (a wooden plate would feel items too), or tripwire strings, which feel anything that crosses them. A plate powers the block under it, and the signal runs under the floor to the redstone that holds the pistons closed: step on a plate and the door opens.
A stone plate stays down for at least 1 second after it is pressed and checks again every second, letting go once nobody is on it, so the door closes a second or two after the last person has passed. The doorway itself is only one block deep: you cross it, between the plates on either side, in a fraction of a second.
Nothing can feel someone standing in the doorway: no detector fits there, since the pistons sweep it and a plate or a string pushed into pops off. A door with no memory, the simplest, closes on them; one with memory reads the order its plates were pressed in and stays open for them, for about twice the blocks.
How to try it
The view shows the door as built, closed: the browser's simulator has no walkers, so nothing steps on its plates here. Drag to look around, pinch or scroll to zoom. Its pressure plates lie in the walkway on both sides of the door, where you step anyway: in the game, walk through from either side.
Measurements
| metric | value | what it means |
|---|---|---|
| door | 2x2 | the size of the doorway it opens |
| open wait | 0 s | the longest a walker waited at the closed door before it opened, in game ticks |
| close delay | 1.35 s | game ticks from the last walker leaving the doorway to the door being flush again |
| stop in doorway | the door closes on them | what the door does when someone stops and stands still in the doorway: stays open for them, or closes on them (it squeezes them and hurts them, half a heart per hurt, until they step out); reported, not required |
Notes from its designer
Opens as you walk up, closes behind you, from either side: a stone plate in front of and behind each door column, any of them opening the whole door, their supports wired under the floor into the torches that hold classic6's pistons closed; each torch sits beside its bottom piston and powers the top one through the stone above it. 42 blocks (the obvious door is 44), no waiting even at a sprint, wherever you walk across the doorway. Stand still in the doorway and the door closes on you and hurts you (half a heart per hurt) until you step out. A mob on a plate opens it too: nothing vanilla tells a player from a mob, so put the plates where mobs can't walk. If the entrance doesn't need to be hidden, two iron doors with plates do the job in about 10 blocks.
Properties
| Study | Automatic doors |
|---|---|
| Kind | Automatic door: opens as you walk up, closes behind you (2×2 piston door) |
| Blocks placed | 42 |
| Box | 8×5×3 (120 blocks of space) |
| Made of (the blocks that change state) | redstone torch, redstone wire, smooth stone, sticky piston, stone, stone pressure plate |
| Design file | auto-door-raised-torch |
The design file
Design file (37 lines)
# Automatic door: opens as you walk up, closes behind you · 42 blocks · no waiting, even sprinting # https://vjeux.github.io/redstonepedia/circuits/autodoor/auto-door-raised-torch.html name: auto-door-raised-torch circuit: auto-door port door.a: 0 0 0 port door.b: 1 1 0 origin: -3 0 -1 palette: S minecraft:stone A minecraft:smooth_stone P minecraft:stone_pressure_plate[powered=false] W minecraft:redstone_wire[east=none,north=none,power=0,south=none,west=none] T minecraft:redstone_torch[lit=true] K minecraft:sticky_piston[extended=true,facing=east] k minecraft:piston_head[facing=east,short=false,type=sticky] J minecraft:sticky_piston[extended=true,facing=west] j minecraft:piston_head[facing=west,short=false,type=sticky] layer -3: ...SS... ..SSSS.. ...SS... layer -2: ...WW... .SWWWWS. ...WW... layer -1: ...SS... SW....WS ...SS... layer 0: ...PP... TKkAAjJT ...PP... layer 1: ........ SKkAAjJS ........