If you have never used multiplexors, this IC connects a single pin to one of the several outputs, where an output pin is picked using other digital input pins. Think railroad switch, but for electronics, not for railroad.
I had some of those mux board around for quite some time and they are working nicely with Arduino, so I decided to make a copy of a very short schematic and to make my own layout. Why? Well, as usual, to test and be sure I can use them in my own devices later.
- Use a multimeter's continuity testing on the original to ensure I'm using correct pins
- Order a board prototype
- Do a bunch of tests to determine it's not worse than normal breakout boards
- Create a 8-pin layout