8 pin DIP w/6 outputs ?

**dhouston** · - 13th September 2009, 14:33

Originally Posted by Sam

I figure (?) you're talking about tip 2 I/O multiplexing ? That may just work for my application. I'll take a close look at it now, it however means redesigning my PCB and changing the code.

And wouldn't it leave 2 outputs to spare, GPIO.4 and .5 ?

Yes, I meant Tip 2. It was past my bedtime - I meant to say it would leave an input pn free plus two input/output pins.

**Sam** · - 13th September 2009, 19:14

Hey Dave,

Thank you very much, that multiplexing completely solved my issue ! I never thought about doing it like that but once you see it (tip 2) it makes perfect sense. It's just what I needed and it's working great.

You're a great asset to the forum and I really appreciate all your help,

SS

**dhouston** · - 13th September 2009, 19:37

I'm surprised I remembered it. I had a copy of that PDF on a network HDD which failed a few weeks back but vaguely recalled it had several unconventional but simple methods for getting the most out of minimal hardware. I have a new, bigger NAS drive but had not grabbed a copy of the PDF until your post jogged my synapses.

The Atmel AVR ATTiny12 allows you to use MCLR as an open drain output but its pinout is different.

**falingtrea** · - 14th September 2009, 19:38

I think that is officially called "Charlieplexing" and is a method originally though up by someone from Maxim Semi. Check this webpage:

http://en.wikipedia.org/wiki/Charlieplexing