Hi, I made a terminal using a 4 x 7 (+ d.p.) segment LED's. Each of them was driven by a daisy-chained 74LS164, so only 4 wires are needed: Clock, Data, Enable (to avoid flicker) and Reset. Regards, Imre On Mon, 24 Jul 2000, Michael Lapson wrote: > Fred, > > Last summer I made a 7-seg clock once with a C84. I used 7 pins for the > segments and three to choose digits. I reliably scanned the digits with a > 3-to-8 demultiplexer (74HCT138) The decoder didn't require any timing code, > and its fast enough that you can't see any flicker. I don't think i used any > transistors. all the current came out of the 74HCT138. > Mine used 11 pins on the PIC to address 8 digits, but I was able to spell > out stuff on the display other than numbers. If I had used a BCD to 7-seg I > could have trimmed it down to 7 pins. > > -Mike Lapson > > > Fredrik Selin wrote: > > >Subject: [PIC]: 4 x 7-segment LED with only 8 free ports on a 16F84 > > > >Hi everyone!! > > > >I4m building a clock using four 7-segment LED displays and I4ve got >only > >PORTB > >(8 ports) aviable for the displays. Any ideas how to control the > > >displays??? > > >Thanks in advance! > > >Regards, Fredrik > > > ________________________________________________________________________ > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]: PIC only [EE]: engineering [OT]: off topic [AD]: advertisements