transmitting and receiving data from usart by using PIC18F4520

[naveenkr37]

Hi,
I am having a problem in receiving continuous data from USART by using PIC18F4520. I am receiving single character or integer, but i am not receiving correctly strings or continuous integers
here is my code,

"USART TRANSMITTING PROGRAM"

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Code C - [expand]
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#include <p18f4520.h>
 
 
#include "usart.h"
#pragma config OSC = HS
#pragma config WDT = OFF
#pragma config LVP = OFF
#pragma config DEBUG = ON
#pragma config PBADEN = OFF
 
#define TXEN TXSTAbits.TXEN
#define BRGH TXSTAbits.BRGH
#define SPEN RCSTAbits.SPEN
#define CREN RCSTAbits.CREN
#define BRG16 BAUDCONbits.BRG16
#define TXIF PIR1bits.TXIF
//#define RCIF PIR1bits.RCIF
 
 
 
    int str[]={'0','0','0','0','0'};
    int i=4,j=0;
    int a[]={1,2,3,4,5,6},c;
    
 
void USARTInit(void);
void USARTWriteByte(char );
void USARTWriteString( char* );
void USARTWriteInt(int ,unsigned char );
 
 
 
 
void USARTInit()
{
    //Baud Rate = 9600 Bits per Second
    //*** Note: Valid On 20MHz Crystal ONLY ***
    //For other crystal freq calculate new values for SPBRG
    SPBRG=31;
    
    BRGH=0; //low speed
    
    BRG16=0; //for 8bit baud rate
 
    SPEN=1; // serial port enable
 
 
    
TXEN=1; // transmit enable bit
    
 
    CREN=1; //Enable Receiver (RX)
 
 
 
 
}
 
void USARTWriteByte(char ch)
{
    //Wait for TXREG Buffer to become available
while(!TXIF);
 
    //Write data
    TXREG=ch;
 
}
 
void USARTWriteString( char *str)
{
    while((*str)!='\0')
    {
        //Wait for TXREG Buffer to become available
        while(!TXIF);
 
        //Write data
        TXREG=(*str);
 
        //Next goto char
        str++;
 
    }
}
 
void USARTWriteInt(int val,unsigned char field_length)
{
    if(val<0)
    {
        USARTWriteByte('-');    //Write '-' sign for negative numbers.
        val=(val*(-1));             //Make it positive.
    }
 
    //Convert Number To String and pump over Tx Channel.
 
    while(val)
    {
        str[i]=val%10;
        val=val/10;
        i--;
    }
    if(field_length>5)
        while(str[j]==0) j++;
    else
        j=5-field_length;
 
    for(i=j;i<5;i++)
    {
        USARTWriteByte('0'+str[i]);
    }
}
 
 
void main()
{
TRISCbits.TRISC7=1; //set RC7 to input
TRISCbits.TRISC6=0; //set RC6 to output
 
USARTInit();
while(1)
{
 
for(c=0;c<6;c++)
{
USARTWriteInt(a[c],1);
}
 
}
}

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"USART RECEIVING PROGRAM"

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Code C - [expand]
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#include <p18f4520.h>
#include<delays.h>
#include "lcd.h"
#include "usart.h"
 
void LCDStart(void);
 
#pragma config OSC = HS
#pragma config WDT = OFF
#pragma config LVP = OFF
#pragma config DEBUG = ON
#pragma config PBADEN = OFF
 
#define TXEN TXSTAbits.TXEN
#define BRGH TXSTAbits.BRGH
#define SPEN RCSTAbits.SPEN
#define CREN RCSTAbits.CREN
#define BRG16 BAUDCONbits.BRG16
#define TXIF PIR1bits.TXIF
#define RCIF PIR1bits.RCIF
 
void USARTInit()
{
    //Baud Rate = 57600 Bits per Second
    //*** Note: Valid On 20MHz Crystal ONLY ***
    //For other crystal freq calculate new values for SPBRG
    SPBRG=31;
 
    BRGH=0;
 
    BRG16=0;
 
    SPEN=1;
 
    CREN=1;
 
 
    //TXSTA REG
    TXEN=1;
 
 
    //RCSTA
 
    //Enable Receiver (RX)
 
    //BAUDCON
 
          //SPBRGH=0X02;
          //SPBRG=0X08;
 
}
 
 
#pragma idata section3
const unsigned char str[]="recieved data";
char a[6],i=0,c=0;
 
#pragma code
void main()
{
TRISCbits.TRISC7=1;
TRISCbits.TRISC6=1;
Wait(50);
LCDInit(LS_BLINK);
 
Wait(50);
USARTInit();
Wait(50);
while(1)
{
LCDWriteStringXY(4,0,str);
while(!RCIF);
c=RCREG;
a[i]=c;
i++;
LCDStart();
 
}
}
void LCDStart()
{
Wait(50);
LCDClear();
Wait(50);
LCDGotoXY(6,1);
while(a[i]!='\0')
{
LCDData(c);
i++;
}
}

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- - - Updated - - -

i need solution for above problem

 

[bigdogguru]

I would first recommend testing your transmission routines using a PC with terminal emulator software, like Putty, as the receiver.

You can then determine which transmission routines, if any, are not functioning as expected and then remedy the issues.

I would then test the reception routines using a PC with terminal emulator software as the transmitter.

You can then determine which reception routines, if any, are not functioning as expected and then remedy the issues.


Note: When interfacing a devices UART/USART to a PCs RS-232 port, an RS-232 transceiver, like a MAX232, must be utilized or the microcontroller maybe damaged.


Finally, perform a similar test to which you have previously posted, which tests the interaction between two devices using the appropriate routines.


I allows recommend testing individual routines, before testing their interaction between them.


BigDog