Multiplexed Digital Decimal Display!

Hi there, I wonder if any one can advise me on my design of multiplexed digital display. My design uses 4 x BCD to a 16-to-4 multiplexer, that is then connected to a 4-to-7 decoder-driver then to 4-seven segment displays, then to a 4-to-1 multiplexer, phew! Is this as efficient as it could be? Does anyone have a better suggestion? Thanks!

Leon.h said:

Hi there, I wonder if any one can advise me on my design of multiplexed digital display. My design uses 4 x BCD to a 16-to-4 multiplexer, that is then connected to a 4-to-7 decoder-driver then to 4-seven segment displays, then to a 4-to-1 multiplexer, phew! Is this as efficient as it could be? Does anyone have a better suggestion? Thanks!

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What is the design actually doing? - one 18 pin PIC could probably replace most of it, certainly it could easily feed 4x7 segment displays, with nothing more than a few small driver transistors and series resistors for the LED's.

I agree, you have way to much logic. I usually use a port / resistor to drive the display and a transistor to sink the current. Then I just scan through my digits. If I am really tight on pins, I might use a serial shift register to store the 7 digits, or 12 bits to store 7 digits and a control line for each transistor, then it only takes 2-3 lines to run the display.

Leon.h,
Do you want to use a PIC or logic hardware?

If you want to use a PIC, the electronics magazines often have PICs with mulitplexed displays. If you want to do it using logic ICs, then we can help.

Len