Y yanto_kang@yahoo.com New Member May 24, 2009 #1 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 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 May 24, 2009 #2 yanto_kang@yahoo.com said: 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.. Click to expand... hi, Connections drawing. If you require the 74C922 output to hold the data, remove the invertor and connect the /OE to 0V. Attachments esp01 May. 24.gif 13 KB · Views: 431
yanto_kang@yahoo.com said: 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.. Click to expand... hi, Connections drawing. If you require the 74C922 output to hold the data, remove the invertor and connect the /OE to 0V.
Nigel Goodwin Super Moderator Most Helpful Member May 24, 2009 #4 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.
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.