MATRIX 4x4 keypad - Four digit

[puntoxacto]

I need a circuit to use a matrix keypad 4x4 to enter a 4 digit password, the password and the user should be used together with a 7seg display (of course 4 of them) Can anyone help me where I can find it ???
REgards,

 

[IanP]

Here is an example of 4x4 keypad + LED display based on a PIC microcontroller:
http://ww1.microchip.com/downloads/en/AppNotes/00529e.pdf
All what you need to modify is instead of displaying time display number/character of a key pressed ..
Another example is based on 8051 microcontroller:
http://www.hkln.net/doc/8051/example/keypad/index.htm
This one has 4x4 keypad and a single 7-segment display ..
Regards,
IanP