Place any solid block with an item frame and an item on it.
Turn the item to what you want it to be.
Put a comparator behind the block and put redstone dust until the signal goes out.
Put this at the end of the redstone line.
Add a redstone torch to invert the signal.
The redstone torch it the output. You can hook it up to a door or lamp.
Combine multiple of these together to make a password. Each item frame is one digit that can be 1-8.
You can make this more compact but I built it spaced out so it is easier to see.
The creator of this guide has not included tools