Simples :-)
Start with a keypad :-
Open it up...
There is not a lot of space...
(This had a proxy reader, which I removed)
We'll need a few parts, including a freshly milled PCB. All from GitHub.
No space for the spacer...
Fits nicely...
Not forgetting a wire link - sadly I could not manage a layout without this...
Add the RS485 convertor and power regulator and some wires, crop the leads nicely...
Looks tidy... (I then sprayed the bare copper with clear lacquer, by the way).
They keypad has handy 5V pads...
And the A/B wires...
And it fits in nicely...
Put back together...
And it works!
