 |
 |
| View previous topic :: View next topic |
| Author |
Message |
atomy_kwang
Joined: 28 Jun 2008
Posts: 24
|
| How to shift left string on lcd module |
 Posted: Sat Jul 19, 2008 8:38 am |
 |
|
| Code: | #include <16f877a.h>
#fuses hs,nolvp,nowdt,noprotect
#use delay(clock = 20000000)
#use fast_io(B)
#define use_portb_lcd
#include <lcd.c>
#define maxchar 16
char buff[maxchar] = "batman " ;
char c;
int i;
void rotate_string(void)
{
c = buff[0];
for(i=0;i<maxchar-1;i++)
{
buff[i] = buff[i+1];
}
buff[maxchar-1] = c;
}
void display_string(void)
{
printf(lcd_putc," %c ", buff[i] );
}
void main()
{
set_tris_b(0x00);
lcd_init();
while(true)
{
display_string();
rotate_string();
delay_ms(500);
}
} |
this is my code , but i think it is wrong , please help me
ps. i want to shift left string all time on lcd module in the 2 line of lcd
but my code it cannot shift left because a new character is occur in the
same position as old character
ps. in the 1 line of lcd i would like to show another string on the middle of
lcd i can us command :
lcd_gotoxy( , );
ps. i cannot use command 0x07 (shift left) because it shift my string
in the 1 and 2 line of lcd
who know about this , Help me please.
Thank you very much |
|
 |
ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
|
|
| Posted: Sat Jul 19, 2008 5:13 pm |
|
|
The rotate_string() function looks OK to me.
The display_String () function however is wrong: | Code: | | printf(lcd_putc," %c ", buff[i] ); |
This will print: a space, a single random character, and a space.
The printed character is more or less random because when you execute this line the global variable 'i' is at value maxchar and buf[maxchar] is outside of the array.
try: | Code: | void display_string(void)
{
lcd_gotoxy(1,2); // move to first position of line 2
for(i=0;i<maxchar-1;i++)
{
lcd_putc( buff[i] );
}
} |
Another problem: | Code: | #define maxchar 16
char buff[maxchar] = "batman " ; |
The string contains only 14 characters + a terminating zero = 15.
Ther terminating zero is not readable text and might give strange results on your display. Fix by adding an extra space character to your string. |
|
|
atomy_kwang
Joined: 28 Jun 2008
Posts: 24
|
|
| Posted: Sat Jul 19, 2008 11:07 pm |
|
|
| thank you very much for edit code , i can do it successfully |
|
|
|
|
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
|
FAQ 
Search
Register
Profile 
Log in to check your private messages 
Log in
