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5 bit counter with 2 keys

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fjpompeo

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Hi,
I need a 5 bit counter with just two keys up (when pressed count up) and other down (when pressed count down) with decoders for two digit or count from 1 to 32 up or down with A, B, C, D and E outputs to encode a MC145026 remote control encoder.
It may be discrete or PIC.

Regards,

Fernando - Call sign PU2PLL
 

I would guess you can use 2- 74(XX)190 or 74(XX)191.
Just replace XX with whatever IC technology your using ex. XX = LS.

These are 4-bit up/down counters. Just have output of one input the other and you can go up to 8-bit.

As far as the display?
You can use 2- 74(XX)47's These are BCD to 7 segment decoders.
You will need one for each display. Also be careful of current requirement in displays.
The displays should be common anode's. you will need current sinking resistors between display input and segments output (330 Ohm resistor works good for me with man-72's).

Data sheet for IC's easy to find in google.
Unfortunately sometimes data sheets for displays not so easy to find.
Hope this helps.
wa
 

WA,

Very thank you for your reply. 74LS191 is OK as up/down counter but it is a binary not BCD so after 9 the display decoder will show 0, a, b, c, etc... and I need after 9 a decimal seguence or 9, 10, 11, 12,... 31 and 74LS190 is a decade counter now this problem is in the binary code for the 5 bits code to the MC145026.

Fernando
 

fjpompeo

Maybe a 74LS193 might help?

Has same u/d features and clear, borrow and carry features included.

It's still 4-bit but, I think 2 74LS193 can get you closer to what your looking for.

This might be another way to look and solution to problem.
One other solution might be the loading of each number into a memory.
Then It shouldn't matter if binary. A 5 bit mux (or 8 bit) might do the trick.
For example, if binary 00000 entered, output of mux points to 0 in memory. if binary 01010 (10 dec) input, then output points to 10 loaded into memory.

I'm sorry I don't know much about MC145026. But I hope this helps.

Hope this helped somewhat.
wa
 

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