Redstone Dance Machine (Minecraft)

Dance Machine 1

Wide view of dance machine.

Legend:

Emerald: Activation Line
Red: Reset Line
White: Input Lines
Orange: Display Lines
Purple: Memory Circuits
Blue: Subtraction Lines
Diamond: Score Line
Yellow: Score Sorting Circuit
Black: Hopper Clock
Brown: Path Selection Circuits
Cyan: Output Path Lines
Gold: Output Path Splitters
Light Grey: Game Counter
Green: Shutoff Line

Dance Machine 2

Overview of main dance area. Pressure plates encircled by stairs to keep players from drifting away from pressure plates (like bumper rails on a bowling lane). Purely optional, but I can't seem to get a decent score without them.

Dance Machine 3

Overview of scoring system.

Dance Machine 4

Input lines below the pressure plates.

Dance Machine 5

Monostable pistons (left) in the input lines prevent players from camping on pressure plates to score.

If the input piston (center) is extended while the corresponding signal is active (from the gold lines), the scoring piston (right) will be quasi-powered by the extended gold block.

Dance Machine 6

The scoring line can be powered by any of the redstone blocks.

Dance Machine 7

The scoring line weaves it way up into the Score Sorting Circuit (yellow).

Dance Machine 8

The Score Sorting Circuit decides which Memory Circuit (purple) to route the scoring signal to. If it receives an input from a Memory Circuit (purple), the scoring line is routed to the Subtraction Line (blue) for that circuit. Otherwise, it tries the next one until it gets to the final one.

Dance Machine 9

Close up of a section of the Score Sorting Circuit.

Dance Machine 10

When a Subtraction Line (blue) is powered, it de-powers the piston above a Memory Circuit (purple) for 2 ticks.

Dance Machine 11

The Memory Circuit (purple) continuously loops back on itself with the same signal strength.

When the piston is retracted, two things happen.
1) The Memory Circuit clears itself. This is necessary for a weaker signal strength to take its place.
2) The redstone dust next to the block being retracted de-powers. This allows the weaker signal to loop back and input itself into the Memory Circuit.

The piston then extends and the new, weaker signal strength is locked in. The strength of the Memory Circuit is lowered by one each time the Subtraction Line is activated.

Once the Memory Circuit completely loses power, the Score Sorting Circuit (yellow) routes the Score Line (diamond) to the next Memory Circuit.

Dance Machine 12

The signal strength from the Memory Circuit (purple) is spiraled down a 3x2 path. If the signal is strong enough, it will invert all of the torches and none of the redstone lamps will be powered. Each time the Memory Circuit loses a signal strength, the signal will travel one less and a torch will be un-inverted (de-inverted? in-inverted? verted?) and a redstone lamp will become powered.

Dance Machine 13

At last, the engine that makes it possible.

Dance Machine 14

The Activation Line (emerald) locks the Hopper Clock (black [even though it looks dark brown]) until it receives a signal.

Dance Machine 15

The Hopper Clock contains 2 items. Any less and the Path Selection Circuits malfunction.

More may need to be added if built in a multiplayer server.

Dance Machine 16

The Hopper Clock osculates between powering the Path Selection Circuits (brown) and the Output Path Lines (cyan).

Dance Machine 17

The Path Selection is determined by Hopper-Droppers. The two one the left have 2 items each and the one on the right has 5 items.

Dance Machine 18

One (of the two) Hopper-Droppers on the left. When powered, the Dropper will randomly select one of its items and drop it into the Hopper. A redstone signal is then pulled from the Hopper with a Comparator.

Dance Machine 19

If the redstone dust is dropped into the Hopper, the Comparator will output a signal strength of 1 and nothing will happen.

Dance Machine 20

If the Shovel is dropped, the Comparator will output a signal strength of 3 and the signal will trigger a monostable piston which will send a 1 tick pulse to the next piston, swapping the position of the redstone block.

Dance Machine 21

Here the redstone block is lowered and the two pistons on either side are un-powered. When the redstone block is retracted both of the pistons on the side will extend and alter the path that the Output Line (cyan) takes.

Dance Machine 22

And here is the other junction in the Output Line. One block will always be raised while the other one is lowered (it is powered by the other Hopper-Dropper, which contains the same items).

There can only be one path to the display.

Dance Machine 23

The third Hopper Dropper has 5 items in it, but again, only the Shovel will produce a 3 strength redstone signal.

Dance Machine 24

The third Hopper-Dropper (top right) will activate the center piston 1 out of every 5 turns on average. If activated, it will pull back the routing block from its default position (shown). This essentially overrides the selections made by the first two Hopper-Droppers.

When the signal is turned off, a falling edge pulse will push the routing block back to its default position.

Dance Machine 25

Okay, math time!

The Hopper-Dropper on the right will override the ones on the left 1/5 of the time. The Hopper-Droppers on the left will produce 4 unique patterns (0-0, 0-1, 1-0, 1-1), with each pattern corresponding to a unique line. So, 4/5 of the time, each of the four lines on the left will have a 1/4 chance of being used; irrespective of what the previous pattern was. 4/5 X 1/4 = 1/5

So, each of the 5 lines has an equal chance of being selected (depending on how random the Dropper selection really is, I haven't checked Minecraft's game-code to see how a Dropper's randomness is generated, but it seems random enough).

Dance Machine 26

The Output Path Splitters (gold) split the Output Paths (cyan) to the main display and to the Score Line (diamond).

Dance Machine 27

Upper half of the Output Path Splitters.

Dance Machine 28

Lower half of the Output Path Splitters.

Dance Machine 29

The Game Counter Line (light grey) takes a signal up to a Memory Circuit (purple) every time the Output Line (cyan) is activated.

Dance Machine 30

A 1 tick pulse is sent to the two pistons (upper-middle-ish) from the Game Counter Line. This signal only reaches the Subtraction Line (blue) 1 out of every 4 pulses.

Dance Machine 31

Alternate view showing the monostable piston activated by the Game Counter Line.

Dance Machine 32

Same deal as the other Memory Cells. Retracted piston clears the Memory Circuit and allows for a signal strength of one less to take its place.

Dance Machine 33

Display Line (orange, center) works using exactly the same principals as the ones on the left. The only difference is that this one is horizontal (and much simpler) and the ones on the left are vertical.

Dance Machine 34

Shutoff Line (green) receives signal from Memory Circuit (purple).

Dance Machine 35

When the Shutoff Line (green) stops receiving a signal from the Memory Circuit, it inverts and cuts the signal from the Activation Line (emerald), which then turns off the Hopper Clock.

Dance Machine 36

Reset Line (red) sends a signal directly to all off the Memory Circuits.

Note that the Reset Line cannot be activated (via a button on the players side of the display) while the Activation Line (emerald) is powered.

The Activation Line becomes powered when a record is in the Jukebox.

Dance Machine 37

The Reset Line (red) introduces a 15 strength signal into the Game Counter's Memory Circuit (purple). The piston does not need to be retracted because a stronger signal will always overpower a weaker one.

Dance Machine 38

This is why I prefer Memory Circuits over Hoppers for score-keeping. They can be reset instantly. No need to wait on a Hopper to drain.

Dance Machine 39

Vanity shot #1.

Dance Machine 40

Vanity shot #2.