[Voja] inserted a Microchip PIC12 series microcontroller between the speaker and the unlock button. All a user has to do is tap out the right Morse code password on the call button in the lobby.

But we were impressed with [SirDan’s] Morse code decoder built with the graphical MakeCode. Granted, it is reading 5 element groups from a button on the BBC micro:bit and not worrying about ...

Morse code, on the other hand ... Operators would push down on a button attached to a small slab of brass that made an electrical connection between two wires. The connection sent electricity ...