Reference for Buddy Block Use

[Vexalor]

I have recently been building a number of circuits using buddy blocks, and thought it might be useful to other circuit-builders to know what block updates and state changes they are capable of detecting.

Further, FC is currently allowing suggestions for making certain block updates detectable by the buddy block. Please don't spam him with requests, but, if you believe one of the unsupported block update notifies would be extremely useful for you, you can go to the suggestions subforum.

Many of the circuits I have been building have been for pure amusement on my part or for research (for this thread), but let me get down to the business of listing:

Things buddy can detect (so far):

-Block placement
-Block breakage (except that of other buddy blocks)
-Any flow change in a fluid
-Falling of sand, gravel, or dead weight (not past the buddy block, only if landing in an adjacent space)
-Fire creation and extinguishing
-Eating of cake
-Production of sound/particles by cake
-Silverfish entering a block
-Furnace beginning to burn and extinguishing its flame
-Rail lines curving to create a corner
-Powder Keg igniting
-Redstone ore activating
-Dirt becoming farmland or vice versa
-Farmland or planter being fertilized or losing fertilization
-Movement of piston
-Growth of flowers and tall grass
-Spread/death of grass/mycelium on dirt
-Opening of a chest
-Tree growth
-Leaf decay
-Change in orientation of a block (e.g., a gearbox being right clicked)
-Sugarcane and hemp growth
-Growth of pumpkins and melons (blocks)
-Melting/freezing of ice
-Growth of pumpkin/melon stems
-Enderman removal/placement of block (having great difficulties testing; code seems to indicate this should be detectable)
-Any change in mechanical power state of axle, gearbox, millstone, etc. (but not the redstone states of these blocks, for instance redstone on gearbox)
-Rotation of turntable and any blocks that it rotates
-Setting the speed on a turntable
-Second block of stoked fire disappearing
-Expansion/compression of bellows
-Kiln becoming active due to a stoked fire being created under it
-An item dropping from a finished kiln firing
-Filter being added to hopper
-Activation/deactivation of light block
-Block broken by saw
-Moving pulleys/platforms
-Nether Groth growth
-Growth of Blood Wood trees
-Growth and maturation of blight
-Creation of mossy and cracked stone brick with lava and water
-Activation or deactivation of a portal if adjacent to where actual portal blocks are/will be
-Eating of grass by sheep, etc.
-Opening/closing of doors and fence gates
-Spiders shooting webs
-Lightning strike
-Creation of mossy cobblestone due to nearby mob spawner


Things buddy cannot detect:

-Hydration/dehydration of farmland
-Opening/closing of trapdoor
-Growth of wheat, carrots, and potatoes
-Changes in the state of redstone dust or any redstone device (intentional)
-Opening the inventory of any storage block aside from the chest
-Change in water level of cistern, whether by player or weather
-Placement/Removal of Eye of Ender in End Portal Frame
-Insertion/Removal of Discs from Juke Box
-Setting the Delay on a Redstone Repeater
-Growth of nether wart
-Stoked fire appearing
-Other Buddy Block triggering (probably counts as redstone state change)
-Conversion of unfired pottery texture to interim texture between unfired and fired in a kiln
-Item entering the inventory of a storage block (cauldron, hopper, etc.)
-Things cooking in the crucible, furnace, cauldron, etc.
-Beacon activating
-Damage to the Dead Weight (impossible to test; code seems to indicate that it can't be detected anyways)
-Breaking of adjacent buddy blocks


I will hopefully be updating this list. If anyone has any corrections, please state them, but before you say that something in the "cannot detect" section worked for you in the past, remember that Mojang removed a large number of block update notifies in 1.5 in an unsuccessful attempt to get rid of BUD switches in vanilla.

EDIT: If anyone has a suggestion for any state change/block update for me to test and add, it would be most appreciated, seeing as I have run out of ideas.

[FlowerChild]

<cringes at the inevitable spam of update requests> :)

[BlackCat]

Enderman removal/placing counts as movement of a block, therefor it will be detected.

And IIRC nether wart does trigger one, but I suppose I could easily be wrong.

[Gilberreke]

The only one that'd be useful to me would be useful would be the repeater changing, as that would essentially turn the repeater into a swanky four-way lever if combined simply with a 4bit memory cell, but that's already possible with a button and four redstone lamps and I think I recall the suggestion has already been made before and rejected.

Basically, you could make some very cool interfaces for machines, but it'd be largely aesthetic and I know I'm the only one that really cares about novel input devices.

Growth of nether wart might be useful too I guess. Never had a need for it though.

[Vexalor]

And IIRC nether wart does trigger one, but I suppose I could easily be wrong.

Just did some extensive tests. Mojang wiped this when they wiped wheat, carrots, and potatoes to kill the BUD switch farm.

<cringes at the inevitable spam of update requests> :)

I was actually surprised to see how many state changes were detected by the buddy block, and how few even potentially useful ones weren't (considering Mojang's rampage against BUDs). But then again, there's always going to be that someone who wants the buddy block to detect when their farmland gets hydrated...

[TheGatesofLogic]

I'm rather excited for the fencegate change, but I wonder how exactly he is doing that one (I imagine he is reverting the notify on the fencegate, which IMO would be vastly preferable to a special case because it would reactivate a significant number of my broken builds -piston BUD issues -.-)

[Gilberreke]

my broken builds -piston BUD issues -.-)

FC did warn that using those was highly discouraged as it was exploit usage and might break your builds down the road :p

[Vexalor]

The only one that'd be useful to me would be useful would be the repeater changing, as that would essentially turn the repeater into a swanky four-way lever if combined simply with a 4bit memory cell, but that's already possible with a button and four redstone lamps and I think I recall the suggestion has already been made before and rejected.

Good news! I just discovered that the same thing can be accomplished by changing the time setting on a turntable. Changing the time setting switch on a turntable triggers a block update, but setting the delay on a repeater does not, for no apparent reason.

[Ethinolicbob]

Buddy will also detect fertilization and consumption of fertilization on planters.
Not sure about the same on farmland

[FlowerChild]

Not sure about the same on farmland

It should.

[Vexalor]

Not sure about the same on farmland

It should.

Yep, just tested. It does. (Added to list)

[Gilberreke]

Good news! I just discovered that the same thing can be accomplished by changing the time setting on a turntable. Changing the time setting switch on a turntable triggers a block update, but setting the delay on a repeater does not, for no apparent reason.

Those are horizontal too. Cool! Will use.

[Vexalor]

Interesting... buddy blocks do not respond when an adjacent buddy block is destroyed (they respond when one is placed or any other block type destroyed). I assume this is intended.

[Gilberreke]

Interesting... buddy blocks do not respond when an adjacent buddy block is destroyed (they respond when one is placed or any other block type destroyed). I assume this is intended.

I think it is and that it's due to feedback loops between two buddy blocks.

[Vexalor]

Just saw an interesting idea proposed by Gates as an early game weather detector: to leave out a cistern to fill up with water to detect when it is raining and shut off a windmill. The rising water level would be detected by a buddy, which applies directly to this thread. Will test. I know emptying a cistern by bottle will not result in a block update, but who knows? With rain?

EDIT: Scrap that. If Gates comes by here and sees this, I just wanted to let him know that not only does filling the cistern with rain not produce a block update, but it also takes so mind blowingly long to even partially fill the cistern that the whole process would be pointless to shut down a windmill in time before overload. Further, I had to restart the test multiple times due to the testing grounds being outside in the rain, where spiders shot webs at me, triggering the BUD. (Added to list)

[dawnraider]

Just saw an interesting idea proposed by Gates as an early game weather detector: to leave out a cistern to fill up with water to detect when it is raining and shut off a windmill. The rising water level would be detected by a buddy, which applies directly to this thread. Will test. I know emptying a cistern by bottle will not result in a block update, but who knows? With rain?

EDIT: Scrap that. If Gates comes by here and sees this, I just wanted to let him know that not only does filling the cistern with rain not produce a block update, but it also takes so mind blowingly long to even partially fill the cistern that the whole process would be pointless to shut down a windmill in time before overload. Further, I had to restart the test multiple times due to the testing grounds being outside in the rain, where spiders shot webs at me, triggering the BUD. (Added to list)

Not to mention that by the time you can get a buddy, you can get a DB, which is actually cheaper in terms of redstone/lapis.

[TheGatesofLogic]

Not to mention that by the time you can get a buddy, you can get a DB, which is actually cheaper in terms of redstone/lapis.

well, the idea was that you could use a vanilla BUD switch to detect it, but obviously that idea is shot. I know the idea used to work but was extremely unreliable unless you had about 15 cisterns (its a random event)

[Vexalor]

well, the idea was that you could use a vanilla BUD switch to detect it, but obviously that idea is shot. I know the idea used to work but was extremely unreliable unless you had about 15 cisterns (its a random event)

Now it makes more sense. Ah well, it was a good idea, but, nope, any state change for the cistern doesn't seem trigger a block update.

EDIT: I just tested it even though I know it doesn't work to see how quickly the cisterns fill, and even with twenty they still fill extremely slowly, so it could just be that Mojang slowed them down or it could be something BTW did, but either way they seem totally useless for this purpose.

EDIT: This is just a vanilla bug actually, MC-7530, that prevents most cisterns from filling with rain at all.

[Vexalor]

A strange thing that keeps happening--and I don't know whether this is a bug or a known quirk--is that almost always the buddy block will trigger for no reason at all a few minutes after being placed. It seems only to happen when I am near by, however, and can be quite annoying with false alarms when I am testing these things.

EDIT: That would be my bad, folks; I can't reproduce it, so I'll just assume it was me, even though it happened a few times.

EDIT: What do you know? Not my bad, it seems. It only happens when a) I am nearby and b)there are multiple buddy blocks adjacent to each other. If someone could tell me whether this is known behavior or not, that would be most helpful, as, if it is not, I ought to file a bug report.

EDIT: Holy crap, I use way too many edits.
I totally forgot that grass despawning under other blocks triggers a block update. You may now insult my stupidity.

[Six]

A strange thing that keeps happening--and I don't know whether this is a bug or a known quirk--is that almost always the buddy block will trigger for no reason at all a few minutes after being placed. It seems only to happen when I am near by, however, and can be quite annoying with false alarms when I am testing these things.

EDIT: That would be my bad, folks; I can't reproduce it, so I'll just assume it was me, even though it happened a few times.

EDIT: What do you know? Not my bad, it seems. It only happens when a) I am nearby and b)there are multiple buddy blocks adjacent to each other. If someone could tell me whether this is known behavior or not, that would be most helpful, as, if it is not, I ought to file a bug report.

EDIT: Holy crap, I use way too many edits.

Uhh, are you placing them on grass by chance?

[Vexalor]

Uhh, are you placing them on grass by chance?

Yes I am, and I am an absolute idiot, as it turns out. Thank you anyways. I really need to actually start thinking about the fact that GRASS DESPAWNS under other blocks before raising alarm.

[dawnraider]

Not to mention that by the time you can get a buddy, you can get a DB, which is actually cheaper in terms of redstone/lapis.

well, the idea was that you could use a vanilla BUD switch to detect it, but obviously that idea is shot. I know the idea used to work but was extremely unreliable unless you had about 15 cisterns (its a random event)

Oh. Whoops. I forgot those things existed. I myself don't find much use of those, which don't even auto reset without a lot of work, and make use of a glitch, and I tend to forget about things I don't use. (I actually forgot ore drops xp until i played a super hostile map)

[milkmandan]

Huh, so no crop growth detection but fertilization change detection. Should make carrot/potato farms a lot easier to construct.

Also, the bellows change made me think of a ridiculously expensive bellows timer coupling a buddy, torch and BD.

[TheGatesofLogic]

Huh, so no crop growth detection but fertilization change detection. Should make carrot/potato farms a lot easier to construct.

Also, the bellows change made me think of a ridiculously expensive bellows timer coupling a buddy, torch and BD.

expensive, but the most compact you'll find ;)

[Six]

Huh, so no crop growth detection but fertilization change detection. Should make carrot/potato farms a lot easier to construct.

Also, the bellows change made me think of a ridiculously expensive bellows timer coupling a buddy, torch and BD.

expensive, but the most compact you'll find ;)

From the 'Show us your builds!' thread:

Mr. Bellows sheep begs to differ!

Spoiler

Show

The cobble is necessary to keep the operator from catching on fire!