minecraft-java-editionminecraft-redstone
I am trying to make a "Zombies" map and you need five rotten flesh to open the door. I made hopper to put the items in the chest with a comparator to power the door. No matter how many items I put in the chest the comparator only sends a length of one to the redstone.
What can I do to fix this?
This setup works:
One of your items is an arrow, the other is any non-dispensing item like redstone.
Arrows will fire and miss the tripwire. Items will hit it then burn up, triggering a signal. You can use the items you suggested: arrow, cobble, cobble, arrow and the desired signal will be generated (well, the inverse).
As with most counting problems in Minecraft, the answer is eggs.
Take a look at my sample setup.
To the right, we have a monostable circuit to shorten the input (the button) down to 1 tick. I use Sethbling's favored design, the repeater is set to 3.
The Centerpiece is a Hopper-Dropper-Counter (a hopper and dropper pointing into each other), containing, in this case, 9 Eggs (or anything that stacks to 16) and 10 Cobblestone (or anything that stacks to 64), for a total of 19 items. You realize this is 1 short, but that's actually fine.
The comparator turns to 3 when all items are in the hopper. In this case, the torch at the bottom of the picture turns off.
The last component is a Repeater-Lock. On each button press, the hopper will update to whatever redstone signal is on the bottom torch before the button was pressed. So if it's at three bars after 19 clicks, it will unlock the hopper on the 20th click, causing all items to go back into the dropper.
To make something happen every 20th click, you should get the signal from the block next to the hopper (i.e. the state of the locked repeater), it is only ever off 1/20 of the time. You could put redstone dust underneath, or put a torch on top, for example (but watch out for signal inversion).
Design notice: I used a variation of this for a three state enchanting room (lvl 1, lvl 18, lvl 30 enchants), using 2 wooden swords, and repeaters checking for a signal >0 and >3, respectively.
Best Answer
Assuming you're using a small (non-double) chest, try filling it like so:
Then set up your redstone roughly like this:
The comparator will output a signal with strength 1 if there are between 1 and 123 pieces of flesh in the chest, and strength 2 (or higher) if there are more. Putting 115 pieces of flesh in the chest means that five more pieces are needed to increase the strength. Once those five pieces are inserted, the repeater will activate, and power the door.