PA3040
Advanced Member level 3
Dear All
This is reference to pic 16f877a MCU keypad 4x4
I am writing a program for Keypad, so I used portb without interrupt
0 - 3 as out put and 4 - 7 as in put with PORTB internal pull_up
I masked it when I pressed number 1, the RC0 LED tern on and press 2, the RC1 LED tern on and so on
It is working with some errors, I mean when I touch the keypad LED will tern on here and there and toggle
finally I add external pull_up ( four 2.2k resistors to Vcc to RB4,RB5,RB6,RB7) You will wonder now it is working fine
Can I have Advice on this
I need to drive this CCt without external pull_ups
Thanks in advance
This is reference to pic 16f877a MCU keypad 4x4
I am writing a program for Keypad, so I used portb without interrupt
0 - 3 as out put and 4 - 7 as in put with PORTB internal pull_up
I masked it when I pressed number 1, the RC0 LED tern on and press 2, the RC1 LED tern on and so on
It is working with some errors, I mean when I touch the keypad LED will tern on here and there and toggle
finally I add external pull_up ( four 2.2k resistors to Vcc to RB4,RB5,RB6,RB7) You will wonder now it is working fine
Can I have Advice on this
I need to drive this CCt without external pull_ups
Thanks in advance