hi … keypad is connected | Miscellaneous › Others › Circuit diagram for 4*4 keypad interfaced with P89V51RD2 › hi … keypad is connected October 8, 2011 at 11:19 am #6687 QaisarParticipant hi … keypad is connected with PO.. PO needs PULL UP resistor .. use 10K pull up resistor and ur problem will be solved. here the code is for 4*3 keypad . but u can modify it easily … i already posted a diagram named CODE LOCK.. you can see that diagram , hope it will solve ur problem .,. regards..
