Design a calculator that can key in complex number.

[yanto_kang@yahoo.com]

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]

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.

 

[yanto_kang@yahoo.com]

Thanks a lot Eric

Thank you Eric!!

 

[Nigel Goodwin]

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.

 

[yanto_kang@yahoo.com]

Thanks a lot Nigel

Thanks Nigel!!