[PIC] problem with uart TRANSMISSION (using dsPIC30F2020, matlab and ft232)

[maxwell_30]

Hi everyone,
i have written a small code to transmit 5 numbers from matlab to the PIC via FT232.
Depending on the number received, a particular led blinks. When the number 5 is received, the MUC transmits back all the 5 numbers received till then to the pc @ 115200 bps.

For some reason my UART transmission is not working and am getting more than 300 random values in matlab when am expecting only 5 values (though the UART reception is working and the leds are blinking as per the number received).

#include<p30f2020.h>
#include<libpic30.h>
#include"delay.h"

_FOSC(CSW_FSCM_OFF & OSC2_IO & HS );
_FOSCSEL(PRIOSC_PLL);
_FWDT(FWDTEN_OFF);
_FGS(CODE_PROT_OFF);
_FPOR(PWRT_OFF);

int x;

// Function prototypes
void _ISR _U1RXInterrupt(void);
void _ISR _U1TXInterrupt(void);
void initUart(void);
void putHex(); 

char Buf[10];
char * Receiveddata = Buf;

void initUart(void){
    
	U1MODEbits.UARTEN=  0;    //UART1 Disabled
	U1MODEbits.ALTIO =  1;   // Use alternate IO
	U1MODEbits.BRGH =   0;    //Use standard Bit rate
        U1MODEbits.PDSEL =  0;    //8 bit no parity
        U1MODEbits.STSEL =  0;    //One stop bit
    
        IPC2bits.U1RXIP =5;//2;//Set UART1 RX Int Priority 0-7, 0=disabled 7=Highest
	IPC2bits.U1TXIP =4;//TX Priority 2
	//IEC0bits.U1RXIE = 1;//Enable UART1 Receiver Interrupt
   	//IEC0bits.U1TXIE = 1;//Enable UART1 Tx Interrupt
   	IFS0bits.U1RXIF =0; //Set UART1 RX Int Flag=0
    
    
        U1STAbits.UTXISEL0 = 0; 
        U1STAbits.UTXISEL1 = 0; 
	U1STAbits.UTXBRK  = 0; 
	U1STAbits.URXISEL = 0;
    
        //U1STAbits.UTXEN   = 1;   // Enable transmit
     
	
	//U1BRG = (FCY/16*Baud Rate)-1 WITH BRGL
        //FCY = FCY = Primary Osc X 2 WITH PLL 
        U1BRG =207; // 115200 baud  16 MHz Crystal BRGL
     
	U1MODEbits.UARTEN=  1;    //UART1 Enabled
        IEC0bits.U1RXIE = 1;//Enable UART1 Receiver Interrupt
	IEC0bits.U1TXIE = 1;//Disable UART1 Tx Interrupt
	U1STAbits.UTXEN   = 1;   // Enable transmit
    
} 
 

void __attribute__((__interrupt__, __auto_psv__)) _U1RXInterrupt(void)
{    
    x = U1RXREG & 0x0F;
    _U1RXIF=0;              //clear RX Interrupt Flag
    *(Receiveddata) = x;
    Receiveddata++;
}

void __attribute__((__interrupt__, __auto_psv__)) _U1TXInterrupt(void){
	_U1TXIF=0;              //clear TX Interrupt Flag

}


 void putHex() 
 { int i=0;
     for(;i<5;i++)
     {
     while(U1STAbits.UTXBF==1) continue;  //Checks if Buffer is Full and w8ts for it to have one location empty 
		U1TXREG=Buf[i];
     }
    return;     //Loops till Transmission is over 
}  

int main()
{
 _TRISB0 = 0;
 _TRISB1 = 0;
 _TRISB2 = 0;
 _TRISB3 = 0;
 
 delay_us(100);
 initUart();
 while(1)    
 {
     if(x==1)
     {  
         _LATB0=1;
         delay_ms(5000);
         _LATB0=0;
         delay_ms(5000);
     }
     else if(x==2)
     {
        _LATB1=1;
         delay_ms(5000);
         _LATB1=0;
         delay_ms(5000);
     }
     else if(x==3)
     {
        _LATB2=1;
         delay_ms(5000);
         _LATB2=0;
         delay_ms(5000);
     }
     else if(x==4)
     {
        _LATB3=1;
         delay_ms(5000);
         _LATB3=0;
         delay_ms(5000);
     }
     else if(x==5)
     {
         putHex();
         while(!U1STAbits.TRMT) continue;
     }
 } 
     
 return(0);
}

can somebody please tell me what is the problem in my code?

my matlab code is:

k=0;
s = serial('COM3');
set(s,'BaudRate',115200);
fopen(s);

% ENTER PIC RELATED CODE HERE
for i=1:5
    b=input('Enter');
    fwrite(s,b,'int8','async');
end

while k ~= 5
    k=fread(s);
    disp(k);
end

pause(5);
fclose(s);
delete(s);

 

[Aussie Susan]

I suggest that you go back to my reply to your similar question about reception with the UART - especially the part where I talk about ensuring the PIC frequency is correct as that is the common cause for receiving more characters than expected in the time.
Also check the part where I talk about using a scope on the line to check the BAUD rate.
Susan