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 support@ccsinfo.com
A real stupid problem

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



Joined: 23 Sep 2011
Posts: 32

View user's profile Send private message AIM Address

A real stupid problem
PostPosted: Mon Oct 03, 2011 5:54 pm     Reply with quote
Hey!

Ok here is my problem....I'm trouble shooting my circuit board, and all the bits on Port A, E, and 1 bit on C go directly to a socket so I can drop in an LCD screen. However, one of the bit's isn't working properly PIN_A4, or pin 6 positioned on PIC16F877. So I have hooked all the wires to LED's so I can see them work but I cannot make PIN_A4 work for the life of me. I looked at the datasheet and it says it's a bi-directional pin so I don't know.

here is my code:
Code:

#define LCD_DB7         PIN_A0
#define LCD_DB6         PIN_A1
#define LCD_DB5         PIN_A2
#define LCD_DB4         PIN_A3
#define LCD_ENABLE      PIN_A4
#define LCD_RS         PIN_C2
#define BACKLIGHT_RED   PIN_E0
#define BACKLIGHT_GREEN   PIN_E1   
#define BACKLIGHT_BLUE   PIN_E2

#include <16F877.h>
#fuses HS,NOWDT,NOPROTECT
#use delay(clock=20000000) //Crystal Oscillator @ 20MHz
//#use rs232(baud=9600,xmit=PIN_C6,rcv=PIN_C7)

void StartupSettings();

void main() {
   StartupSettings();

   while(1) {
      output_bit(LCD_DB7, 1);
      output_bit(LCD_DB6, 1);
      output_bit(LCD_DB5, 1);
      output_bit(LCD_DB4, 1);
      output_bit(LCD_ENABLE, 1);
      output_bit(LCD_RS, 1);
      delay_ms(1000);
      output_bit(LCD_DB7, 0);
      output_bit(LCD_DB6, 0);
      output_bit(LCD_DB5, 0);
      output_bit(LCD_DB4, 0);
      output_bit(LCD_ENABLE, 0);
      output_bit(LCD_RS, 0);
      delay_ms(1000);   
   }

   return;
}

void StartupSettings() {
   set_tris_a(0x00);
   set_tris_c(0x00);
   set_tris_e(0x00);

   return;



Any ideas?
bungee-



Joined: 27 Jun 2007
Posts: 206

View user's profile Send private message

PostPosted: Mon Oct 03, 2011 6:14 pm     Reply with quote
Look at the datasheet again on page 42. There is a line on page 41
Quote:
The RA4/T0CKI pin is a Schmitt Trigger input and an open-drain output.
pay attention on underlined text Wink

I had the similar experience the first time I came across this particular port. Embarassed
For most application you can simply put 10k resistor to the 5V line.
Wolf



Joined: 23 Sep 2011
Posts: 32

View user's profile Send private message AIM Address

PostPosted: Mon Oct 03, 2011 6:42 pm     Reply with quote
Oh damn it! I guess I need to start cut up or solder parts off my circuit board. Thank you
asmallri



Joined: 12 Aug 2004
Posts: 1634
Location: Perth, Australia

View user's profile Send private message Send e-mail Visit poster's website

PostPosted: Mon Oct 03, 2011 10:59 pm     Reply with quote
Wolf wrote:
Oh damn it! I guess I need to start cut up or solder parts off my circuit board. Thank you


No you just need to add a pull-up resistor.
_________________
Regards, Andrew

http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!!
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