Hello internet! Welcome to the Redstone Contraptions Blog! In this blog, I will be going through the step-by-step processes of building some pretty cool redstone circuitry and devices. My work is not copyrighted in any way, so feel free to use it as you will, provided that you include my name as credit.

CONTRAPTION #01: The Chest-Opened Door
This is an interesting setup. The user will see a chest next to a door. When the proper amount of redstone dust is placed in the chest, the door will open! It is also possible to replace redstone dust with any other item if desired.
The Necessary ingredients are:
2 Hoppers
1 Chest (preferably not trapped)
1 Redstone Comparator
28 or more Wood Planks
32 Redstone Dust (Or 9 dust and 23 of desired item)
1 Redstone Repeater
1 Iron Door

Step 1:
Place two hoppers and place the chest on top.


Step 2:
Place the comparator facing away from the bottom hopper.


Step 3:
Place redstone dust (or desired item) in the shown fashion. One in each of the first four slots, and thirteen in the last slot.


Step 4:
Surround the top hopper in wood planks.


Step 5:
Build two walls around. Be sure to leave a hole for where the door will be.


Step 6:
From the door-ready wall, place one block immediately in front, and two to the side, leading behind the contraption.


Step 7:
From the comparator (which should be on) place two redstone dust and the repeater.


Step 8:
Continue the redstone circuit to the two wood planks leading to the doorway.


Step 9:
Place the door.


Step 10:
If all worked correctly, when you place the remaining six redstone (or item) in the chest, the door will open!


Further note:
Adjusting the amount of items in the hopper and how far away the repeater is will change how many items will be needed to be put into the chest.