rs232 problem

[delifisek]

Hi;

I m trying to get 8 consecutive char s from pc and send it to antenna. After that get a char from antenna and send it back to pc. Program can carry out this mission once however i want it to continue for unlimited time. I m not sure what the problem is caused by actually. My opinion is that buffer of pic is full and it doesn't accept any more character! However even if I use "reset_cpu", it doesn t sort it out! Code is below!

Pic 16f877

used components; max232, easy radio transceiver and a wire as antenna

Thanks in advance!

[grasspuddle]

one main thing is that you shouldn't reset the cpu, the while loop will repeat the code for you

definately remove that

[PCM programmer]

[bwgames]

I am using very similar components (easy radio and PIC18F452).

Something like below should do the job much more simply?

[delifisek]

Thanks to u all guys!
Especially to u,bwgames;

I combined all your suggestions and it is working now!
I want to suggest smt which is not relevant to my problem!

I think every one should post the fixed program so that we can see the problem and see the fixed situation! My fixed code is below!

[delifisek]

Hi again;

This time it is expected my program to carry out the same mission by using interrupt routines! I wrote a code by the help of Pic example programs! However it is not working and I think the cause of problem might be interrupt routines!
1.)I wonder if we can use interrupts "int_ext" or "int_rda" or else "int_tbe" with B2 and B3 port or not? If not how can we empty buffer via B2 and B3 using interrupt?
2.)If buffer gets full and char continue to be sent, will the program go to "#int_rda" routine? If so buffer value will change and it might cause a problem.

Regards! Delifisek!

Code is below!


#include <16F877.h>
#fuses HS,NOWDT,NOPROTECT,NOLVP
#use delay(clock=4000000)
#use rs232(baud=19200, xmit=PIN_C6, rcv=PIN_C7)
#define KEYHIT_DELAY 50000 // in milliseconds

#use fast_io(D)





#define BUFFER_SIZE 8
BYTE buffer[BUFFER_SIZE];
BYTE next_in = 0;
BYTE next_out = 0;
int k=0;


#int_rda //If there is char on serial, detect it!!
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;
enable_interrupts(int_tbe);} // Buffer full !!
}

void put_to_a( char c ) { //send the response of second board!!

putc(c);

}

#USE RS232(BAUD=19200, XMIT=PIN_B2,RCV=PIN_B3)

#int_tbe

void serial_isrb() {

putc(buffer[next_out]);

next_out=(next_out+1) % BUFFER_SIZE;

if(next_in==next_out){

k=1;

disable_interrupts(int_tbe);}

}

char b_timed_getc() { //Wait for the response from second board for a limited time!!
long timeout;
char retval;

timeout=0;
while(!kbhit() && (++timeout< KEYHIT_DELAY*100))
delay_us(10);
if(kbhit())
retval = getc();
else
retval = 0;
return(retval);
}



void main() {

char c1;

enable_interrupts(global);



SET_TRIS_D( 0x01 );

while (!input(PIN_D0) );

output_low(PIN_D5);

{

enable_interrupts(int_rda);

while(k==1);

k=0;

next_in=0;

next_out=0;

c1=b_timed_getc();

if(c1==0) {

reset_cpu();

// printf("please swipe your card again");

}

put_to_a(c1);

} while (TRUE);
}
[/code]