> 12 lines is for sissies. A real hacker would use 9 lines. And no extra
> components, just the PIC, displays and resistors. And up to 8 displays
> with the same 9 lines. OK, maybe N transistors if the PIC pins can't
> handle the common current (N = number of displays). And maybe 8 extra
> transistors if the PIC pins can't handle the segment current either, but
> I have never worked out that case.

That's not so easy if you decide to put the transistors in there (which are
needed if you want more than 25mA total per digit).  Your scheme is clever,
but relies on the fact that PIC pins can have 3 output states.  It could be
done, but would require more external parts than just a BJT and a base
resistor.


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads