kosoniscs Posted December 28, 2004 Report Share Posted December 28, 2004 I've made a board which has four 7seg. displays multiplexed. They are connected at the same bus and a PIC controls the turn on and off time of each one of them. The problem is that, in Brazil, PIC is not so cheap and I would like to use a digital circuit to make it. The project is kind of a counter so that, it is not necessary to use a microcontroler. All I need to do is connect four different counters in the same bus. Can anybody help me with suggestions or circuits that could make it?Another doubt that I have is about the noise caused by the mechanical contact of the buttom. Using a microcontroler I know how to 'don't see' the noise. How can I do this kind of thing using CMOS counter? Is there an ic that do this?Thanks Quote Link to comment Share on other sites More sharing options...
surajbarkale Posted December 29, 2004 Report Share Posted December 29, 2004 Search the term 'Switch Debounce' & you will get hardware schmatic for it. As for the counting task check out http://www.ee.washington.edu/stores/DataSheets/cd4000/74c926.pdf but I fear it would turn out more expensive than PIC.P.S. Check out AVR or 89C2051/89C51 they are cheaper than PIC. Quote Link to comment Share on other sites More sharing options...
kosoniscs Posted December 29, 2004 Author Report Share Posted December 29, 2004 Thanks...Actually I need two independent counters that will use two displays...I'm looking at fairchild site at this moment to see if they have what I need. You know could you tell me?Thanks again Quote Link to comment Share on other sites More sharing options...
surajbarkale Posted December 30, 2004 Report Share Posted December 30, 2004 Check out CD4033 it has internal counter & 7 segment decoder. You can use 74hc244 to interface it with a bus.But the discrete logic makes it cumbursome to mux display lines (you need too many IC's). And eventually cost of all IC's will equal a microcontroller. ;D Quote Link to comment Share on other sites More sharing options...
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