Is it possible to chain input multiplexers together to use one PIN on the Mega?

i.e.  MEGA-PIN20 > HC4067-PIN4 (PARENT) > HC4067-PIN15 (CHILD)

and then assign a button to the "CHILD" multiplexer.

The data.cfg file could be:

B20.4.15 ALT_NAV

I have seen this done with a DM13A attached to an output multiplexer, but not input.

Thanks, Neil.
Dec 24, 2019 in General Questions by

1 Answer

No, we don't plan this.
In case of output to LEDs, it's a typical "shift-register" output. DM drivers are the shift registers with lock "memory".

Multiplexers work as "switches" with addressing.
Read description here.
So, for 16 inputs you need 4 address lines.  Making them "cascade" is useless in terms of pins saving (if making several muxes in cascade), because this needs more address lines, and can drastically complicate the configuration and coding (and lower the speed of inputs scan).

But, it doesn't mean that SimVim interface will not be developing and changing further, to improve it and use more connection and communication options


Dec 24, 2019 by