[PIC] how to send string through serial port

[Deexith Hasan]

the following code works well in proteus but not in my development board ...received k alone y?..

#include <htc.h>

void delay()
{
unsigned char i;
for(i=0;i<255;i++);
}

void serialwrite(unsigned char data1,unsigned char data2,unsigned char data3)
{
TXREG=data1;
while(TXIF==0);
TXIF=0;
TXREG=data2;
while(TXIF==0);
TXIF=0;
TXREG=data3;
while(TXIF==0);
TXIF=0;

}




void main()
{
TXSTA=0X20;
RCSTA=0X90;
SPBRG=129;
BRGH=1;
TRISC7=1;
TRISC6=0;
TRISA=0XFF;
TRISD=0X00;
TRISB=0X00;
serialwrite('k','b','c');
while(1);


}

 

[betwixt]

PIC type?
What baud rate are you expecting?
What is the clock speed?
Is TXIF already set when you enter serialwrite()?

Brian.

 

[FvM]

I don't see a problem with the code. Writing to TXIF is useless, but doesn't hurt (bit is RO, see datasheet). It's cleared automatically when the TXREG data is transferred to UART shift register. So consequently, you wait for TXIF being set before writing to TXREG.

May be wrong baud rate? Or receiver set to 9-bit frame? (Parity enabled or two stop bits).

 

[MUKESH.K.S]

post your project folder as zip file including simulation....
Which frequency crystal u r using ? have u changed frequency of pic in simulation according to your circuit?

 

[Deexith Hasan]

PIC18f4520
20Mhz crystal
9600 baud rate
i am doing temp data logging my actual code is

#include <htc.h>


unsigned char temp2;
unsigned char temp3;
unsigned char lsb;
unsigned char msb;
unsigned char mmb;


void dataconv(unsigned char);
void dataconv(unsigned char data)
{
lsb=data%10;
lsb=48|lsb;
data=data/10;
mmb=data%10;
mmb=48|mmb;
msb=data/10;
msb=48|msb;
}


void delay()
{
int i;
for(i=0;i<12275;i++);


}


void serialwrite(unsigned char data)
{
TXREG=data;
while(TXIF==0);
}

void interrupt ISR(void)
{
if(RCIF==1)
{
RC0=1;

if(RCREG=='a'){
serialwrite('b');
dataconv(temp2);
serialwrite(msb);
delay();
serialwrite(mmb);
delay();
serialwrite(lsb);

dataconv(temp3);
serialwrite(msb);
delay();
serialwrite(mmb);
delay();
serialwrite(lsb);
}


}
}



void main()
{
TXSTA=0X20;
RCSTA=0X90;
SPBRG=129;
BRGH=1;
TRISC7=1;
TRISC6=0;
TRISA=0XFF;
TRISD=0X00;
TRISB=0X00;
ADCON0=0X01;
ADCON1=0X0C;
ADCON2=0X2D;
PEIE=1;
GIE=1;
RCIE=1;
serialwrite('a');
delay();
serialwrite('b');
while(1)
{

delay();
ADCON0=0X05;
GODONE=1;
while(GODONE==1);
PORTD=ADRESH;
temp2=ADRESH;
delay();
ADCON0=0X09;
GODONE=1;
while(GODONE==1);
temp3=ADRESH;

}

}