 |
 |
| View previous topic :: View next topic |
| Author |
Message |
jmaurin
Joined: 29 Mar 2008
Posts: 26
Location: Ribeirão Preto, SP, Brasil
|
| USART fgets() not working |
 Posted: Thu Jul 24, 2008 11:28 pm |
 |
|
Hi all.
I'm trying to communicate 2 pics but it's not working...
With a single char, everything works....but not for a string.
This is my code:
display PIC:
| Code: |
char temp[50];
while (TRUE)
{
n++;
fgets(temp,rs1);
printf(lcd_putc,"%s %d",temp,n);
}
|
proc. PIC:
| Code: |
while (1) {
output_toggle(PIN_B7);
fprintf(rs1,"Jonis %d\n\r",n);
delay_ms(1000);
n++;
}
|
i already tried to use \0 after %d but still not working. What's wrong?
I need to pass a full string from PIC A to PIC B and fgets would be perfect for my needs. |
|
 |
Ttelmah
Guest
|
|
| Posted: Fri Jul 25, 2008 5:15 am |
|
|
First, I'd suggest you pull the code for 'get_string', in input.c, and modify this to use your required stream. Gets, is a 'dangerous' function, since if the carriage return doesn't arrive, the data _will_ overflow the buffer, damage other variables, and lead to program failure...
The code in input.c, is simple to copy, and produce your own version using the named stream.
Now, you say 'usart'. Are you actually using the hardware USART, or a software UART?. Have you got the 'errors' statement in your RS232 definition?. What is your baud rate?. What is actually happening (is B7 toggling)?.
Best Wishes |
|
|
jmaurin
Joined: 29 Mar 2008
Posts: 26
Location: Ribeirão Preto, SP, Brasil
|
|
| Posted: Fri Jul 25, 2008 9:32 am |
|
|
| Ttelmah wrote: | First, I'd suggest you pull the code for 'get_string', in input.c, and modify this to use your required stream. Gets, is a 'dangerous' function, since if the carriage return doesn't arrive, the data _will_ overflow the buffer, damage other variables, and lead to program failure...
The code in input.c, is simple to copy, and produce your own version using the named stream.
Now, you say 'usart'. Are you actually using the hardware USART, or a software UART?. Have you got the 'errors' statement in your RS232 definition?. What is your baud rate?. What is actually happening (is B7 toggling)?.
Best Wishes |
I'm using hardware USART on both 628A and 4550 in Isis (proteus) Simulator. Using 'putc()' and 'kbhit()' or 'getc()' everything works fine! The problem is with fgets().
Let me explain...I have a project for my car. With an 18F4550, i can read almost all sensors from my car and steering well buttons. Since my original tape doesn't have CD, i changed from a pioneer CD player....so my steering well doesn't work anymore. With my project, i'll read, know and send controls from steering well to my new pioneer cd player, which has "Wired Control" connector (and my project still working with all other sensors too). All functions like sensors status are displayed in onboard computer display, which is original from my GM Vectra.
This display uses i2c communication, but with +1 port (3 in total) and some modifications. This modifications uses some delays and theses delays are generating errors while pressing some buttons....i mean, i need to press the buttons for a few ms to work, instead of just push and leave. Because of this and others problems i'll put and 16F628A dedicated to display communication. What i need is to send string from one pic to another and if is possible, is better to get the full string and process instead of char by char on the display control.
The proc. pic (4550) will send a lot of messages to display, but since display has some delays, it will just use the last full valid string.
ex:
A send (every 50ms):
Teste 1
Teste 2
Teste 3
Teste 4
Teste 5
and display control has 100ms delay, so it will use only:
Teste1
Teste3
Teste5
BTW, i'm using 9600 baud. Can i use more with these pics? |
|
|
jmaurin
Joined: 29 Mar 2008
Posts: 26
Location: Ribeirão Preto, SP, Brasil
|
|
| Posted: Fri Jul 25, 2008 11:10 am |
|
|
now, i'm trying with simple code but still not working....
on display pic:
| Code: |
while(TRUE) {
c=getc();
lcd_putc(c);
}
|
on master pic:
| Code: |
while (1) {
output_toggle(PIN_B7);
putc('j');
putc('o');
putc('n');
putc('i');
putc('s');
delay_ms(1000);
n++;
}
|
What's wrong? I can see just "jo" on the LCD. |
|
|
|
|
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
