PDA

View Full Version : 4 pin 4 x 4 keypad interface using pic basic pro


dunlao_john
- 15th January 2009, 02:55
hello. i am currently working in my institutional project..it is a digital electronic lock, using an lcd and a 4 x 4 keypad. i'm having problem maximizing the pins of my PIC16f628a. A conventional 4 x 4 keypad uses 8 pins of the pic microcontroller. is there anybody has an idea on how to convert an 8 pin keypad interface to 4 pin keypad interface? hope someone can solve my problem..thank you ver much!!!
mackrackit
- 15th January 2009, 05:14
You could use an 8 bit parallel in serial out shift register or maybe get some ideas here
http://www.picbasic.co.uk/forum/showthread.php?t=3250
http://www.picbasic.co.uk/forum/showthread.php?t=10110
Archangel
- 15th January 2009, 05:21
hello. i am currently working in my institutional project..it is a digital electronic lock, using an lcd and a 4 x 4 keypad. i'm having problem maximizing the pins of my PIC16f628a. A conventional 4 x 4 keypad uses 8 pins of the pic microcontroller. is there anybody has an idea on how to convert an 8 pin keypad interface to 4 pin keypad interface? hope someone can solve my problem..thank you ver much!!!You could use analog solution, different value resistors for each coloum.