Problem With RS232

[Guest]

Hello,
I am using 18F2620 and I wrote a very simple code that send data to PC and get a char from PC. It does sending data out but not receiving any data.
I am using build in serial io monitor that comes with PIC C. The hardware handshaking is in place but for simplicity I set them off in Serial monitor so there should be no hardware handshaking.
The code is as follow:

#include <18F2620.h>
#include <stdio.h>
#use delay(clock=8000000)
#fuses NOWDT,WDT128,INTRC, NOPROTECT, NOIESO, NOBROWNOUT, BORV21, PUT, NOCPD, STVREN, NODEBUG, NOLVP, NOWRT, NOWRTD, NOEBTR, NOCPB, NOEBTRB, NOWRTC, NOWRTB, NOFCMEN, NOXINST, NOPBADEN, NOLPT1OSC, NOMCLR
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8)

#define toggle(x) {if(input(x)) output_low(x); else output_high(x);}

void beep(int16 delay,int16 freq)
{
int16 i;
for(i=0;i<delay;i++)
{
delay_us(freq);
toggle(PIN_C2);
}
}

void main()
{
byte c;
setup_oscillator(OSC_8MHZ); // selecting internal osc 8mhz
// setting output tri state register
set_tris_a(0xff);
set_tris_b(0);
set_tris_c(0);
// needed by my hardware
output_high(PIN_C1);
// first beep
beep(100000,300);
printf("Software was compiled on ");
printf(__TIME__);
printf("\r\nBefore getc\r\n");
// second beep
beep(10000,100);
c=getc();
// third beep
beep(1000,200);
printf("read data =%c\n\r",c);
printf("Program finished\r\n");
}


The result:

The above program write the requested message to output and I can hear two beep so I believe it come and stops at getc.

If I change the value for TRIS-C to 0b11000000. The received message is garbage but I can hear two beeps.
TRIS-C=0b10000000 : The received message is garbage but I can hear two beeps.
TRIS_C= 0b01000000 : The received message is correct and I can hear two beep.

I all cases, when I am tying to send a data (for example 0x22) to the PIC so I can hear the third beep, I couldn’t hear it ( and can’t see the remaining messages)

Could you please help me to find a solution for this?

Best regards

[Ttelmah]

You may in part at least be hitting the 'run off the end' problem.
In the PC, when you compile a C program, the 'main', is called from the OS, and when it ends, you return to this OS, and the processor keeps running. On the PIC, the 'main' is the entire program. Hence the code _must_ stay inside the program, and not 'run off the end'. If (for instance, and without any 'setup' instructions), you have a main like:

[Guest]

Thanks,
I add the suggested code ( while(1); at the end and ERRORS in #use RS232) without any sucess:
I will draw the wiring and post it later.

I couldn't find any refrence to toggle in PIC C, where can I find information about it?

Best regards

[rwyoung]

[Guest]

Thanks
My compiler is version 3.214 and the IDE is 3.212 which I belive isn't very old.

I couldn't find any refrence to output_toggle in readme.txt or help file, but when I used it in my program, it works without any compilation error.

Any suggestion on RS232 problem?

best regards

[rwyoung]

[Guest]

Hello,

How can attach a file to the forum?
I want to attach the schematic of the design.

Best regards