I was hoping there'd be something more elegant than having a full Arduino and power supply between keyboard and computer.
You can use Arduino board and power it (and the Amiga keyboard) from USB.
I built this couple of years ago and have used it succesfully with my Amiga keyboards (also my A2000 Cherry one), the code is pretty much from the thread linked above. It could use a more elegant casing but I haven't bothered
