CCS C Software and Maintenance Offers
FAQFAQ   FAQForum Help   FAQOfficial CCS Support   SearchSearch  RegisterRegister 

ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

CCS does not monitor this forum on a regular basis.

Please do not post bug reports on this forum. Send them to CCS Technical Support
i can't make work pcf8574a interrupt

 
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion
View previous topic :: View next topic  
Author Message
jd_batista



Joined: 15 May 2008
Posts: 1

View user's profile Send private message Yahoo Messenger

i can't make work pcf8574a interrupt
PostPosted: Thu May 15, 2008 9:46 am     Reply with quote
I have a trouble with this device. I have switches in all input pins. Initially INT are low but when i turn off any switch and the input go low; INT doesn't do anything. Please every info about how to read pcf8574a with a 16f877a. I really appreciate it.
thank you
PCM programmer



Joined: 06 Sep 2003
Posts: 21708

View user's profile Send private message

PostPosted: Thu May 15, 2008 12:07 pm     Reply with quote
The PCF8574A data sheet says this:
Quote:
Open-Drain Interrupt Output


Do you have a pull-up resistor on the \INT pin ?
You need one. Add a 4.7K pull-up to that pin.
Display posts from previous:   
Post new topic   Reply to topic    CCS Forum Index -> General CCS C Discussion All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group