USART C18 Issued(RFID)

[binzer]

Its actually 0x0A...ID....0x0D.
Ill try that code now... by the way look at the image attached.

Hmm, I wonder if that would read the "Home Again" tags for dogs??

 

[junior000]

usart transmitting garbage values!!

hi,
i am trying to test my 18f4550 hardware usart functions through windows hyperterminal...but it doesn't seem to respond.
sometimes the 18f4550 transmits some garbage values.please help!
i am programming the code using the usb bootloader software.

my external crytal is 11.092 MHZ.
so for 2400 baud rate

spbrg = (11092000/2400)/64 - 1 = 71.21

------------------------code---------------------------

#pragma udata
extern void _startup (void);
#pragma code _RESET_INTERRUPT_VECTOR = 0x000800
void _reset (void)
{
_asm goto _startup _endasm
}
#pragma code
#pragma code _HIGH_INTERRUPT_VECTOR = 0x000808
void _high_ISR (void)
{
;
}
#pragma code _LOW_INTERRUPT_VECTOR = 0x000818
void _low_ISR (void)
{
;
}
#pragma code
#include <p18f4550.h>
#include <usart.h>
void main(void)
{
OpenUSART( USART_TX_INT_OFF & USART_RX_INT_OFF & USART_ASYNCH_MODE & USART_EIGHT_BIT & USART_CONT_RX & USART_BRGH_LOW,71 );
while(1)
{
putcUSART('f');
while (BusyUSART());
}
CloseUSART();
}

is there a problem with the code???

 

[kasunth]

Hi guys,
I have a big problem in serial communication in 18f452
After i programe the mcu to send a string to PC via RS 232, PC dont receive what i sent.it displays only two other characters in hyper terminal .

I ll give my code. Its in C18
my MCU is 18f452 in 10 MHz
i use a bootloader
Please help me guys

thank you


/* This program Blinks the LEDs in PORTB */


#include <stdio.h>
#include <P18CXXX.h>
#include <timers.h>
#include <usart.h>

#pragma code page // This code make sure the program starts from 0x0004, not from 0x0000
#pragma config WDT = OFF

//----------------------For LCD-----------------------------------------
#define RS PORTEbits.RE0
#define dirRS TRISEbits.TRISE0
#define RW PORTEbits.RE1
#define dirRW TRISEbits.TRISE1
#define E PORTEbits.RE2
#define dirE TRISEbits.TRISE2
#define DATALCD PORTD
#define dirDATA TRISD
#define LCDBusy PORTDbits.RD7

void LCDdata (unsigned char);
void busylcd(void);
void LCDinit (void);
void LCDDelay( void );
void lcdcmd(unsigned char);
void stringtoLCD(unsigned char *m);

//For USART
void OpenUSART( unsigned char config,unsigned int spbrg);
void putsUSART( char *data );

//---------------------------------------------------------------------

void delay (void) // user define delay function
{
long i,C;
for (i=0;i<3000;i++)
C = C+1;
}

void main (void) // main function
{
char LCDString[6]="kasun";
int integer=0;
char *LCDStringPtr;

LCDStringPtr=&LCDString[0];
TRISD = 0;
PORTD = 0;
TRISB = 0; // Port,pin direction configuration
PORTB = 0;
TRISC = 0;
PORTC = 0;
TRISCbits.TRISC7 = 1; // make sure this pin is input
ADCON1=2;

LCDinit();

//for USART

OpenUSART( USART_TX_INT_OFF & USART_RX_INT_OFF & USART_ASYNCH_MODE & USART_EIGHT_BIT & USART_CONT_RX & USART_BRGH_HIGH,64);

while (BusyUSART());
PORTB = 255;
putsUSART(LCDStringPtr);

while (1) // this is how to make a never ending loop.
{
lcdcmd(0x1);
lcdcmd(0x2);
stringtoLCD(LCDString);
delay();
}

}
//////////////////////////////////////////////////////////////////////////////////////
//LCD finctions------------------------------------------------------------------------
//////////////////////////////////////////////////////////////////////////////////////
void LCDdata (unsigned char value)
{
busylcd();
TRISD = 0;
DATALCD = value;
RS=1;
RW=0;
E=1;
LCDDelay();
E=0;

}
//--------------------------------------------------------------------------------------
void LCDinit(void)
{
TRISE=0;
lcdcmd(0x38); //set 8-bit mode and 2 lines
lcdcmd(0x10); //cursor move & shift left
lcdcmd(0x06); //entry mode = increment
lcdcmd(0x0c); //display on - cursor blink on
lcdcmd(0x01); //clear display
}
//-------------------------------------------------------------------------------------
void busylcd(void)
{
RS=0;
RW=1;
TRISD=255;
E=0;
LCDDelay();
E=1;
while(LCDBusy==1){
E=0;
LCDDelay();
E=1;
}
}
//-------------------------------------------------------------------------------------
void lcdcmd(unsigned char temp)
{
busylcd();
RS=0;
RW=0;
TRISD=0;
DATALCD=temp;
E=1;
LCDDelay();
E=0;
}

//--------------------------------------------------------------------------------------
void LCDDelay(void)
{
int i=0;
for (i=0;i<250;i++);

}
//---------------------------------------------------------------------------------------
void stringtoLCD(unsigned char *m)
{
unsigned char i;
i = 0;
while(m != 0)
{
LCDdata(m);
i++;
}

}