18f252 rs232 int_rda problem

[tesla80]

Hi all,
I've connected 18F252 with max232 to PC, when the first power came; 3 unlikely interrupts show up, and then when i try to send something from hyperterminal (or terminal or Docklight) ,there is no interrupt so it doesn't take any data, it sends data but it doesn't take back.

i did the similar work before with 16 series Pics and they work good.What kind of differences can be on F252, What am i suppose to do about it ?

Code is here:

[PCM programmer]

1. Add the 'ERRORS' parameter to your #use rs232() statement.

2. Don't put a printf() inside your #int_rda routine. It takes too long
to send all those bytes. It blocks rda interrupts from being processed
while it is sending those bytes. If interrupts are blocked, the incoming
bytes can't be removed from the UART receiver. It will then get an
overrun error. Without the ERRORS statement, the overrun error
will cause the UART receiver to lock-up. It won't work.

[tesla80]

Thanks,
Added errors but show up a warning (variable never used : rs232_errors)

[PCM programmer]

Try the simple program shown at the end of this thread:
http://www.ccsinfo.com/forum/viewtopic.php?t=30380

[tesla80]

it's working with your code

[PCM programmer]

You have TRISC.7 (Rx) set incorrectly. You're setting it as an output
and it must be set as an input pin.

[tesla80]

yes, you are right. I wouldn't think this.

SET_TRIS_C(0b10000000);
TRISC=0x80;
Thanks, it's working good now!

[sella]

I'm doing a RF project using PIC18F252 as the receiver.There are 1 transmitter and 2 receivers. When i use the sample program EX_SISR.C, the data sent was received and displayed in virtual terminal. I need to use the received data to compare with another data to detect either it is same with receiver 1 or receiver 2.Then LED at receiver 1 or receiver 2 must be on.But now i am not able to compare the data.
Below are the sample code.
#if defined(__PCM__)
#include <16F877.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)

#elif defined(__PCH__)

#include <18F252.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP,
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#endif
#include <string.h>

#define G1_LED PIN_B2
#define BUFFER_SIZE 32
BYTE buffer[BUFFER_SIZE];
BYTE next_in = 0;
BYTE next_out = 0;


#int_rda
void serial_isr() {
int t;

buffer[next_in]=getc();
t=next_in;
next_in=(next_in+1) % BUFFER_SIZE;
if(next_in==next_out)
next_in=t; // Buffer full !!
}

#define bkbhit (next_in!=next_out)

BYTE bgetc() {
BYTE c;

while(!bkbhit) ;
c=buffer[next_out];
next_out=(next_out+1) % BUFFER_SIZE;
return(c);
}



void main() {

char Temp_Data;
char string[10]= "THSW1";

enable_interrupts(global);
enable_interrupts(int_rda);

printf("\r\n\Running...\r\n");

// The program will delay for 10 seconds and then display
// any data that came in during the 10 second delay

do {
delay_ms(10000);
while(bkbhit)

putc( bgetc() );
Temp_Data = bgetc();

if(strcmp(Temp_Data,string)==0)

{
output_high (G1_LED);
delay_ms(60000);
}

}while (TRUE);
}
I really need help here. This is my final year project...
Kindly please help me.
thanks

[Ttelmah]

A a comment, the 'variable never used RS232_ERRORS' warning, is just an annoyance of the compiler, and remember is only a _warning_. It does not in itself imply that anything is really wrong, it is just telling you this, so that if it is a variable that isn't used, you can possibly get rid of it, and save a small amount of RAM
If you add the 'errors' statement to the RS232 setup (which should be the default), the compiler does two things. First it adds to the getc code, routines to clear errors if set. Then it generates a variable called 'RS232_ERRORS', and when it clears an error, makes a copy of the error bits into this. Hence you can at any time read this variable, and see what the last error was. However if you don't read the variable, you get the warning, which 'worries' some people, who don't understand what is happening.

Best Wishes

[sella]

Hi! Thanks for the reply.
I tried to compare the data received with another data, but I still couldn't get the output desired. I can't understand why the data is not compared.
Please kindly reply.
thanks