Also reset the segment drive lines befor switching to the next digit
otherwise you will get a 'ghost' of the previous digit on the display. This
is just a bug I encountered when I tried using 7-seg displays.

> Yes, it's called multiplexing.  You only have to tweak the
>  timing between digits to get minimum current draw, while still
>  all of them appearing to be on at the same time.  Not difficult,
>  but may take a few tries to get it just the way you want them.
>
>                                               Regards,
>
>                                                  Jim
>
>
>
> On Mon, 24 January 2000, Russell Farnhill wrote:
>
> >
> > Hi all,
> >
> > I want to make myself a UV exposure box for making PCB's.
> > I need to design a PIC timer board that is capable of
> > counting down any where from 9mins & 59secs, I want to drive
> > 3 7-Segment displays and be able to set the timer by
> > turning a pot which is processed by an ADC on the pic.
> >
> > I was thinking how to drive the display and wanted to know
> > if it sounded ok or not ?
> >
> > First common all the three disp-segs data lines and connect to one
> > of the ports, then take the 3 commons and connect them to separate
> > port pins, then just cycle through each display by outputting the data
> > to the port and pull the relevant common pin to ground for a short time,
> > then repeat for each display in a loop.
> >
> > Is this the usual way of driving more than one display ??
> >
> > Thanks,
> >
> > Russ...
>
> jim@jpes.com