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Design a calculator that can key in complex number.

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Hi All Expert!!

I want to design a calculator that can key in complex number..

I want to know how to connect 4x4 Matrix Keypad and MM74C992 16 Key Encoder on PIC18F4520 microchip..

Your help is very much appreciated..

:)
 

ericgibbs

Well-Known Member
Most Helpful Member
Hi All Expert!!

I want to design a calculator that can key in complex number..

I want to know how to connect 4x4 Matrix Keypad and MM74C992 16 Key Encoder on PIC18F4520 microchip..

Your help is very much appreciated..

:)
hi,
Connections drawing.
If you require the 74C922 output to hold the data, remove the invertor and connect the /OE to 0V.
 

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Nigel Goodwin

Super Moderator
Most Helpful Member
It seems a complete waste to use the keypad encoder, why not just connect the keypad directly to the PIC? - it's 8 I/O pins as opposed to 5 I/O pins, but that's probably not a problem anyway.
 
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