I think I would be inclined to use the parallel port of a PC. A binary counter, a 1-to-8 decoder, and eight 8 bit latches would be all the required circuitry (probably a few gates too). The printer port reset line would reset the counter to 0 for an initial state. The next 8 writes out the parallel port would write data out to the eight latches with the counter and decoder selecting where the data gets latched.
The software code would be ultra simple. You could maintain a eight byte array that you set up and then call a subroutine to "refresh" the parallel port as required. >--- Original Message --- >From: Declan Moriarty <[EMAIL PROTECTED]> >To: Multiple recipients of list CHIPDIR-L <[EMAIL PROTECTED]> >Date: 9/24/02 9:18:30 AM > >I have a need to switch a 64 way exhibition piece in an 8 x 8 matrix. We are >farting about here to impress. The output stage I can manage. It's the >control strategy I am wondering about. Due to design considerations I cannot >multiplex outputs, so driving with 16 switches (8 columns and 8 rows) isn't >practical . > >It has to be controllable by a demonstrator, and they're not printing >characters or any standard shape; what is wanted is an efficient and humanly >usable interface to address these. I looked at remote control ics, but the >interface is too well integrated into a tv. Ditto serial connections. I >haven't multiplied out the combinations, but it is daunting(zillions). There >will be a pic(16f877) based pcb I can attack and alter if needs be, but my >coding skills are primitive. Mind you, the pic16f877 isn't. > >The very basic would be addressing the cells individually via a pc & serial >port. Anyone got a better plan? > > >-- > Regards, > > > Declan Moriarty > > > > >Applied Researches - Ireland's Foremost Electronic Hardware Genius > > A Slightly Serious(TM) Company > >Experience is like a comb, >that Life gives you - AFTER all your hair has fallen out! >-- >Author: Declan Moriarty > INET: [EMAIL PROTECTED] > >Fat City Network Services -- 858-538-5051 http://www.fatcity.com >San Diego, California -- Mailing list and web hosting services >--------------------------------------------------------------------- >To REMOVE yourself from this mailing list, send an E-Mail message >to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in >the message BODY, include a line containing: UNSUB CHIPDIR-L >(or the name of mailing list you want to be removed from). You may >also send the HELP command for other information (like subscribing). > -- Author: Steve Thatcher INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
