Observer


Behavior

In the Computer Edition, an observer will detect changes in its target`s block ID or data value, or the breaking or placing of a block. (Changes in its basic block state, but not its extended/actual block state.) This means that changes like the age of crops will be detected, since they are part of the basic block state that is converted to metadata when the world is saved; be that as it may, changes such as the shape of a fence will not be detected, since those are part of the extended block state, which is not saved when the world is saved.

In the Pocket Edition, an observer acts as a block update detector, and detects anything that causes a block update in that edition. (Note that what causes a block update and how they propagate is very different between the Computer Edition and the Pocket Edition.)

When it detects something, the observer emits a redstone pulse See a specific category of redstone circuits. For other circuits, see redstone circuits. A pulse circuit is a redstone circuit which generates, modifies, detects, or otherwise operates on redstone pulses. See also: minecraft , powering redstone dust Redstone Transparency Yes Luminance No Blast resistance 0 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Availability Survival Drops Redstone (1) Data values See Data values Name See Data values This article is minecraft , redstone comparators Redstone Comparator Transparency Yes Luminance No (7 when powered, in Pocket Edition) Blast resistance 0 Tool Any tool Renewable No Stackable Yes (64) Flammable No Drops Redstone Comparator (1) Data values See Data values Name minecraft and redstone repeaters Redstone Repeater Transparency Yes (partial) Luminance No (7 when powered, in Pocket Edition) Blast resistance 0 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Availability Survival, Creative Drops Redstone Repeater (1) Data values minecraft , as well as powering mechanism components located at its opposite end with power level 15 for 2 game ticks Nearly all video games (including Minecraft) are driven by one big program loop. Just as every gear in a clock is synchronized with the pendulum, every task involved in advancing a game simulation is synchronized (1 redstone tick Nearly all video games (including Minecraft) are driven by one big program loop. Just as every gear in a clock is synchronized with the pendulum, every task involved in advancing a game simulation is synchronized ). In the Java/Computer Edition, the observer outputs strong power, and can strongly power blocks like a redstone repeater. It also has a delay of 1 redstone tick before emitting a pulse.

In Pocket Edition, the observer emits the same kind of pulse as the Computer Edition observer, except that it does not strongly power blocks, and the observer outputs activation power only, similar to a block of redstone Block of Redstone Transparency Partial (blocks light, mob spawning possible) Luminance No Blast resistance 30 Tool Renewable Yes Stackable Yes (64) Flammable No Drops Itself Data value dec: 152 hex: 98 bin: 10011000 Name redstone_block This article is minecraft . It is supposed to have a delay of 1 redstone tick like the Java Edition observer, but in practice it has a 2 redstone tick delay, due to MCPE-15793, a bug causing redstone delays to be incorrect when components are activated by world changes (which, in the case of the observer in MCPE, is the only way it can be activated), as opposed to pure redstone components ticking.

It also counts as a block change/block state change/block update when the observer itself is moved by a piston. When this happens, an observer emits a pulse after being pushed or pulled, but not beforehand.

Observers behave as a transparent block even though they block light. This means they cannot be powered by an external power source, nor power themselves with their own output.

Because observers in the Computer Edition detect changes in the basic block state, and not block updates, they can detect a wider range of phenomena than a block update detector See the redstone circuit. For the block, see Observer. The Block Update Detector, or "BUD switch", is a redstone mechanism that uses quirks in the game in order to detect changes in minecraft (BUD) circuit in the Computer Edition can detect (as some block state changes don`t cause block updates), though it has different limitations. Observers in the Pocket Edition do detect block updates (but not block state changes), and so they detect the exact same things that any other BUD would detect in that edition.

Obtaining

An observer requires a pickaxe to be mined. When mined without a pickaxe, it will drop nothing.

Block
Observer
Hardness 3.5
Tool
Breaking "Punch" redirects here. For the enchantment, see Enchanting#Punch. The Player punches trees and gets wood (click to view animation). Breaking, digging, punching, or mining is one of the most fundamental activities in Minecraft, performed (by minecraft time
Hand 17.5
Wooden 2.65
Stone 1.35
Iron 0.9
Diamond 0.7
Golden 0.45
  1. ⃢₆ₑ Times are for unenchanted tools in seconds.

Videos

Info

An observer is a block that emits a redstone signal when an adjacent block is updated.

Trivia

Crafting

Ingredients Crafting Crafting is the method by which many blocks, tools, and materials are made in Minecraft. In order to craft something, players must move items from their inventory to a crafting grid. A 2×2 crafting grid minecraft recipe Description
Cobblestone⃂+
Redstone⃂+
Nether Quartz











Computer and Pocket editions only

Usage

An observer is placed similarly to a piston Piston Transparency Yes Luminance None Blast resistance 2.5 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Drops Itself Data values See Data values Pistons are blocks capable of pushing most blocks, depending on minecraft , and will observe the block that it is placed against. Unlike many redstone components, the `face` (detection side) points away from the player who placed the block.

In Pocket Edition Pocket Edition Author(s) Mojang AB Jens Bergensten Aron Nieminen Daniel Kaplan Tommaso Checchi Shoghi Cervantes Jason Major Daniel Wustenhoff Tomas Alaeus Mikael "Slicedlime" Hedberg @@@#@@@Microsoft(microsoft.com)###@### Studios 1] Platform(s) Written in C++ 2] Latest version 1.1.2 minecraft the observer block texture has two dots which are at opposite ends when the block is placed. The smaller dot outputs a redstone signal whilst the bigger dot detects the block update. In the Computer Edition, the texture of the detection end is that of an `observing` face.

Limitations

Block state change: Detected
in PE
Detected
in PC/CE

Locking / unlocking a redstone repeater
No No

Changes to the data value of fire that signifies flammable surfaces surrounding fire
No No









Changes in the shape of walls, fences, iron bars, glass panes, stairs, tripwire, redstone dust, vines, melon stem or pumpkin stem
No No



A grass, mycelium or podzol block becoming snowy or not snowy
No No

Changes to inventory of any blocks that comparators measure as containers
No No

Activating / deactivating a beacon
No No

Playing a note block
No No



Opening and closing shulker boxes, chests & ender chests
No No

Success of a command block
No No

Teleporting something by the end gateway
Yes No

Adding / removing contents from a flower pot
Yes No

The opening/closing of the top part of a door by hand, as opposed to by redstone power.
Yes No

Powering / depowering of activator rails
No Yes

Inverting / deinverting a daylight sensor
No Yes


Activation of a dropper or dispenser
No Yes


Activation / deactivation of redstone ore, or of a redstone torch
No Yes

A piston (not the head) extending or contracting
No Yes

Locking / unlocking a hopper
No Yes

Spread of grass to dirt, or decay of grass into dirt
No Yes



Growth of nether wart, forced growth of cocoa pods by bone meal, or growth of vines into empty space
No Yes



Aging of saplings, sugar cane or fire
No Yes

Farmland going through its hydration stages
No Yes

Moving bottles to / from a brewing stand
No Yes
All other block / block state See the definition of the block states. For the files that determine block models, see Models#Block states. Block states are extra pieces of data that further define a block. Contents 1 List minecraft changes Yes Yes

Block data

See also: Data values See values from the latest PC version of Minecraft. For values from Classic, see Data values/Classic. For values from Indev, see Data values/Indev. For values from the Pocket Edition, see Pocket Edition minecraft and Pocket Edition data values
DV Description
0 Facing down
1 Facing up
2 Facing south
3 Facing north
4 Facing east
5 Facing west

Block state

See also: Block states
Name See the definition of the block states. For the files that determine block models, see Models#Block states. Block states are extra pieces of data that further define a block. Contents 1 List minecraft Value Description

⃂facing
north
south
east
west
up
down
The direction the observer is observing. The same direction the player faces, when placing the block.

⃂power
true
false
True while the observer is observing a change and emitting a pulse.

History

Official releaseAnnounce Minecraft 1.0 Starting version 1.0.0 (Nov. 18th, 2011) Latest version 1.12 Paid Yes Website http://www.minecraft.net/ See the official release of Minecraft for the PC. For the version, see 1.0.0. For the first minecraft
1.11 1.11 Official name Exploration Update 1] Release date Nov. 14, 2016 Development versions View all Snapshots 16w32a 16w32b 16w33a 16w35a 16w36a 16w38a 16w39a 16w39b 16w39c 16w40a 16w41a 16w42a 16w43a 16w44a Pre-releases 1.11-pre1 Download Client (.json) minecraft 16w39a 16w39a Type Snapshot Release date Sep. 28, 2016 Snapshot for 1.11 Download Client (.json) Server ◄◄ 1.10.2 ◄ 16w38a 16w39b ► 1.11.1 ►► See the computer edition. For other editions, see Version minecraft Added observer block. When first added, the observers acted as a block update detector See the redstone circuit. For the block, see Observer. The Block Update Detector, or "BUD switch", is a redstone mechanism that uses quirks in the game in order to detect changes in minecraft , and would emit pulses that lasted 1 game tick (0.5 redstone ticks) and had a signal strength of 1. The observer could also power blocks (like a repeater Redstone Repeater Transparency Yes (partial) Luminance No (7 when powered, in Pocket Edition) Blast resistance 0 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Availability Survival, Creative Drops Redstone Repeater (1) Data values minecraft ). It also had no delay between detecting a block update and emitting a pulse, meaning that observers were essentially instant. They were also placed with the observing, or input, side facing the player.
Note: the "arrow" texture on the top/bottom of the observer was pointing the wrong direction (towards the input, rather than the output). This was not noticed by most people, though, since the observer in Pocket Edition Pocket Edition Author(s) Mojang AB Jens Bergensten Aron Nieminen Daniel Kaplan Tommaso Checchi Shoghi Cervantes Jason Major Daniel Wustenhoff Tomas Alaeus Mikael "Slicedlime" Hedberg MicrosoftTechnology company Studios 1] Platform(s) Written in C++ 2] Latest version 1.1.2 minecraft had (and as of 1.0.0 still has) a texture bug where the top & side textures wouldn`t rotate properly (except the output/input sides), causing the arrow texture to always point in the same direction.
16w41a Observers were changed to emit 4 game tick (2 redstone tick) pulses, and their signal strength was changed to 15.
Observers *appear* to no longer strongly power blocks, and now only emit activation power, like a block of redstone Block of Redstone Transparency Partial (blocks light, mob spawning possible) Luminance No Blast resistance 30 Tool Renewable Yes Stackable Yes (64) Flammable No Drops Itself Data value dec: 152 hex: 98 bin: 10011000 Name redstone_block This article is minecraft . (And this may have been the intended behavior for this snapshot.) Be that as it may, in reality, they still strongly power blocks, but the blocks adjacent to those blocks aren`t given block updates, causing weird and buggy behavior.
Observers are now placed with the output facing the player.
Fixed a bug where observers would redirect redstone dust from all 4 directions. (They are only supposed to redirect dust from their output side.)
16w42a The devs attempted to make observers no longer detect block updates happening to air blocks, in order to make observer behavior more predictable. In the process they broke redstone mechanics a bit, so that the block update bug from the previous snapshot now affected repeaters & comparators, too.
16w43a Observer PE.png Fixed the rotation of the "arrow" texture so it would point in the right direction.
General redstone mechanics work as they did before 16w42a, with the exception of the change named below.
Observers now output strong power like in 16w39a, except that they, as well as repeaters & comparators, no longer provide block updates to transparent blocks or air.
16w44a The block update changes relating to redstone from 16w42a & 16w43a were fully reverted.
Observer behavior was overhauled/redefined. The observer changed from a block update detector to a block state change detector. Observers were changed to detect when the block it was observing changed, its basic block state changed, or the block was placed/destroyed. (Note that it does not detect changes in the extended block state, AKA changes that are not saved when the world is unloaded, such as the shape of a fence, or whether or not a repeater is locked.) This change made observer behavior much more predictable, as unexpected/invisible block updates would no longer trigger observers.
Observers were changed to emit a 2 game tick (1 redstone tick) pulse when activated.
Observers no longer output power instantly.
1.11-pre1 Observer.png Changed front (detecting side) texture to be an `observing face`. The "arrow" texture on the top/bottom of the observer was also modified.
The redstone output side now blinks red when it outputs power.
Pocket Edition Alpha
0.15.0 May 2, 2016 Jeb tweeted that Daniel Wustenhoff is a working on a BUD block.
ObserverRejectedGraphics.jpg
Tommaso Checchi tweeted his "rejected graphics" for the block.
build 1 Observer PE.png Added observer block.
0.15.3 Observers are now placed like a piston Piston Transparency Yes Luminance None Blast resistance 2.5 Tool Any tool Renewable Yes Stackable Yes (64) Flammable No Drops Itself Data values See Data values Pistons are blocks capable of pushing most blocks, depending on minecraft and not a log.

Issues

Issues relating to ⃢₀ₜObserver⃢₀₝ are maintained on the issue tracker. Report issues there.

Gallery

Appearance

The Observer has a small red dot on the back. The sides are similar to a Dispenser, but with a gray "belt" on them. The front is decorated with a stone face.

Mechanics

The Observer has two sides: a detector side, and an output side. The output side will create a one-redstone-tick (two game ticks, or 0.1 seconds) if the block at the detector is side is updated or changed. For a more elaborate demonstration, click here.