I/O expanders

[Demon]

This is my offer for the smallest design on the MCP23017 I/O expander in bi-directional mode:

9667


It's possible to smoosh an SOIC with 0603 SMD down to 23mm x 107mm (0.9in x 4.2in), with no support holes (I slide them vertically around the enclosure perimeter. The headers should make for easy access.

9668


Circuit looks like this:

9669


Hopefully I didn't do something real dumb, like on my prototype (A0-2 wired wrong, can only get 111 without hot-jumping wires :D )

[Demon]

Am I the only person that can't stand having VSS above, and VDD below?

I had to go and fix the caps so VDD was above, and VSS below.

9670

[Ioannis]

No, you are not alone! Don't like it, can't stand it!

And bothers me alot when schematics from big companies do that on purpose, to just make your day miserable!

Ioannis