You can hide the hopper by using either minecarts or blocks that are not full height slabs stairs soulsand use a inverted door you can simply open this one with a redstone torch even with block protection it might be long enough to clip through.
Hopper door lock minecraft.
This will lock the door in its current state closed preventing the pressure plate outside from functioning.
Construct a xnor gate where.
From outside walk over the pressure plate and through the door.
But to really hide the piston door better we need to use some advanced redstone circuits.
It s a very simple way to make a door that needs a key.
A good place to start is rogue fox s guide to making an invisible button for a hidden piston door.
The hopper underneath is powered so that it cannot remove items from the top.
Sounds like you re thinking about hoppers wrong.
2 of the wires meet.
The redstone circuit required is simple enough but it gets more complex when adding a dropper a hopper and a redstone comparator.
It s as if hoppers don t just pull items out but push items in.
A door that opens when buttons are pressed in certain order.
Connect to adjacent outputs with and gates.
These outputs are connected to final and gate.
It s a very simple way to make a door that needs a key.
Item sorters are a type of redstone mechanism which can be used to filter specific items into chests they generally work using two hoppers as shown in the schematic the top hopper is filled as shown under the image.
Wait for the door to close then use the lever to push it to the on position.
Final and gate if connected to iron door.
When enough items fill the top hopper the bottom hopper is unpowered so that it can remove the extra.