PIC16F877A+3x4 keypad+7-segment

Status
Not open for further replies.

jameschia

Newbie level 1
Joined
Oct 18, 2011
Messages
1
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,290
Hello everyone.
Would like to ask some question here. Currently I am doing a project that PIC will detect key pressed by keypad and show it on a 7-segment.
The PIC will output 4 bit BCD to drive the 7-segment by CD4511. There is no problem to show number on 7-segment.
But problem do occurred when I testing keypad circuit. I have attached two different circuit with this post "CIRCUITV1" and "CIRCUITV2".
CIRCUITV1 working fine when testing on PIC simulator, but it doesn't work on actual circuit. PIC cannot detect key pressed on keypad since it doesn't respond after I press all the key on the keypad.
After that I change my circuit to CIRCUITV2 and I do some modification on programming logic as well. It working fine with this circuit.
Can anyone advice me what is the problem occurred on CIRCUITV1?
Thank you very much.

 

Status
Not open for further replies.

Similar threads

Cookies are required to use this site. You must accept them to continue using the site. Learn more…