Hello!
This is just a small project I did using item-frames to create a sweet little programmable combination lock. Operation is simple: set the code by rotating the items in the inside frames. Match the frames outside and activate the button to open the door. I've colour-coded all the circuits on wool so I could post a key:

The circuit(s) on the...

• lime, light-blue, red and white are the eight digit-encoders (two of each) and the memory outputs on the receiver side which are just coloured to match the data points
• yellow transmits the data to the memory (serial format)
• orange is a cut-off circuit. This verifies all item frames are present with items in them, otherwise no data is transmitted when the button is activated
• blue is the transmission line and the memory cells
• purple are the XOR gates which compare the set-data with the received data. They all have to be off (A=B) for the door to open
• light-gray is the twelve-input NOR gate which reads the outputs of all the XOR gates and triggers the door accordingly
• gray is the power to the door and from the panel override inputs. The 'keep open' override just powers the door while the 'keep closed' override disables an AND gate that would otherwise power it if the codes match.

The two modules can be placed anywhere and connected with a single line of redstone. There are no pistons in the build, everything is torch-controlled with a delay of roughly 5 seconds to send/process the data.
Let me know if you think of any improvements.

*4,096 possible combinations.



JAVA 1.20.1