7I84U multiplex control panel switches

Hello Folks, 

I searched, but not much came about multiplexing the IO on a 7I84U or other mesa card. My panel will have 28 push buttons, 3 pots and one MPG. I could wire everything to the 7I84U, but with a 5x6 matrix I can mux all the switches, saving IOs. 

How can this be done? Examples would be much appreciated.

Greetings  

This can be done with 5 7I84U outputs and 6 7I84U inputs in conjunction
with the matrix_kb component

If you expect to press more than one switch at a time
you need to add one diode per switch

I'm pretty sure there are examples of this on the forum so a
search for "7i84" and "matrix" might find something...