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serial output problem

Nir boh

hi,
i'm using a- 80c31 microcontroller to send the status
of port bits: p3.3,p3.4,p3.5 using serial comm.
my program works fine only in simulation and i cant
get an idea where is the problem.
i checked the TX pin(11) with a scope and it seems that no data are being sent.

please help...

#include <Reg51.h>
sbit Input1 = 0xB3;     /* P3.3  */
sbit Input2 = 0xB4;     /* P3.4  */
sbit Input3 = 0xB5;     /* P3.5  */

unsigned int Tmr1 = 0;
unsigned int Tmr2 = 0;
unsigned int Tmr3 = 0;

void SendStatus() {
if (Input1 == 0){
        P2 = P2 | 0x03;
        Tmr1 = 0;
        }
if (Input2 == 0){
        P2 = P2 | 0x18;
        Tmr2 = 0;
        }
if (Input3 == 0){
        P2 = P2 | 0xC0;
        Tmr3 = 0;
        }
TI = 0;
SBUF = P2;
while (TI == 0);        /* Wait For Transmit */
if (TF0 == 1) {
        Tmr1 = Tmr1 + 1;
        Tmr2 = Tmr2 + 1;
        Tmr3 = Tmr3 + 1;
        if ((Tmr1>912)&&(Tmr2>912)&&(Tmr3>912)) {
                Tmr1 = 0;
                Tmr2 = 0;
                Tmr3 = 0;
                TR0 = 0;
                TF0 = 0;
                P2 = 0x00;
                }
        else if (Tmr1 == 912) {/* 60 Sec Alarm Hold*/
                P2 = P2 & 0xFC;
                }
        else if (Tmr2 == 912) {/* 60 Sec Alarm Hold*/
                P2 = P2 & 0xE7;
                }
        else if (Tmr3 == 912) {/* 60 Sec Alarm Hold*/
                P2 = P2 & 0x3F;
                }
        else {
                TH0 = 0xFF;
                TL0 = 0xFF;
                TF0 = 0;
                }
        }
}


void main() {

SCON = 0x40; /* 8-bit UART, BaudRate set by Timer-1 */
TMOD = 0x21; /* Timer1 mode 2, Timer-0 mode 1 */
TCON = 0x40; /* Start baud clock */
TR0 = 0;        /* Turn Timer-0 off */
TH0 = 0xFF;
TL0 = 0xFF;
TF0 = 0;        /* Clear rollover flag */
TR0 = 0;        /* Turn timer-0 on */
TH1 = 0xCC;     /* 600 baud 12MHz */
IE = 0x00;      /* Disable serial int */
IP = 0x80;      /* Interrupt priority stopped */
P2 = 0x00;
P3 = 0x00;
Input1 = 1;
Input2 = 1;
Input3 = 1;

while(1) {
  while ((Input1 == 1)&&(Input2 == 1)&&(Input3 == 1)) {
     TI = 0;
     SBUF = 0x00;
     while (TI == 0);/* Wait For Transmit */
     }
     TH0 = 0xFF;
     TL0 = 0xFF;
     TR0 = 1;            /* Turn timer-0 on */
     while (TR0 == 1) SendStatus();
     }
}

Parents Reply Children
  • 0 in reply to Nir boh

    can you write the line for me that
    declare a local variable to store the bits before sending them to the SBUF.

    i'm confused with unsign char ,char ....

  • 0 in reply to Nir boh

    "i'm confused with unsign char ,char ...."

    What, specifically, is the confusion?

    Sounds like you need a 'C' textbook?

    http://www.keil.com/books/

  • 0 in reply to Andy Neil

    that is waaaay too 'politically correct'

    Erik

  • 0 in reply to Andy Neil

    i changed my program, and still i found some
    odd things..

    the result are as this

    send >expected output> alternate output
    1...........0x01..............0x40
    2...........0x02..............0x20
    3...........0x03..............0xA0
    4...........0x04..............0x10
    5...........0x05..............0x50
    6...........0x06..............0x90
    7...........0x07..............0xB0

    the alternate output accures when i
    trigger the input bit again.

    #include <Reg51.h>

sbit Input1 = 0xB3;  /* P3.3 (INT1) bit set, Input 1 */
sbit Input2 = 0xB4;  /* P3.4 (T0)   bit set, Input 2 */
sbit Input3 = 0xB5;  /* P3.5 (T1)   bit set, Input 3 */

unsigned char TxOK = 0;
unsigned char xt = 0;

void serial_IT(void) interrupt 4
{
  if (TI == 1) {
    TI = 0;
    TxOK = 0;
    }
}

/* ~~~~~~~~~~ */
/*   Main Sub */
/* ~~~~~~~~~~ */
void main(){
SCON = 0x40;
TMOD = 0x20;
TR0 = 0;
TCON = 0x40;
TH1 = 0xCC;
TL1 = 0x00;
ES = 1;
EA = 1;

TxOK = 1;
TI = 1;
while(TxOK);

while(1){
if (Input1 == 0) {
        xt = 1;
        if (Input2 == 0) {
          xt = 3;
          if (Input3 == 0) {
             xt = 6;
             }
          }
        else if (Input3 == 0) {
          xt = 4;
          }
        }
else if (Input2 == 0) {
        xt = 2;
        if (Input3 == 0) {
          xt = 5;
          }
        }
else if (Input3 == 0) {
        xt = 7;
        }
else xt = 0;

TxOK = 1;
SBUF = xt;
while(TxOK);
}
}