Interface PIC16F887 with PC (VB.net)

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VB

microcontroller

Hello ..I'm doing my FYP and am having problems with getting data from the PC (vb.net) to the microcontroller (PIC16f887) that will be displayed in LCD 2x16 .. The problem for example I wanna send (hello) to the microcontroller so I get ( hlo) instead of ( hello ) or sometimes i get the 3rd digit or char that am sending from the textbox in VB.net.. for the communication between the PIC and PC am using USB to UART converter and am using startup kit for the microcontroller .

Plz if there anyone could help with this or anyone has similar code .. Thanx in advance :)

here are my codes

PIC16F887 code:

//========================================================================
//	include
//========================================================================
#include <pic.h> 

//========================================================================
//	Configuration
//========================================================================
__CONFIG(FOSC_HS &				//External Crystal at High Speed
		 WDTE_OFF &				//Disable Watchdog Timer
		 PWRTE_ON  &			          //Enable Power Up Timer
		 BOREN_OFF &			         //Disable Brown Out Reset
		 MCLRE_ON &				//MCLR function is enabled
		 LVP_OFF);				//Disable Low Voltage Programming

//=========================================================================									
//	Define
//=========================================================================
#define	rs			RB4				//RS pin of the LCD display	
#define	e			RB5				//E pin of the LCD display
#define	b_light		RC1				//backlight of the LCD display (1 to on backlight)
#define	SW1			RB0				//button (active low)
#define	SW2			RB1				//button (active low)
#define	lcd_data	        PORTD			       //LCD 8-bit data PORT
#define	LED1		       RB6				      //led 1 (active high)
#define	LED2		        RB7				     //led 2 (active high)

//===========================================================================
//	Function prototype				
//===========================================================================
void delay(unsigned long data);			
void send_config(unsigned char data);
void send_char(unsigned char data);
void lcd_goto(unsigned char data);
void lcd_clr(void);
void send_string(const char *s);
unsigned char uart_rec(void);
void beep(void);

void uart_send(unsigned char data);
void uart_str(const char *s);
void send_cmd(unsigned char num, unsigned int data, unsigned int ramp);

//===========================================================================
//	Main function				
//===========================================================================
void main(void)
{
																		
	unsigned char a;											
		
	PORTA = 0;							// Clear Port
	PORTB = 0;
	PORTC = 0;
	PORTD = 0;

	TRISA = 0b00000000;					// set PortA as OUTPUT
	TRISB = 0b00000011;					// set PORTB<1:0> as INPUT
	TRISC = 0b00000000;
	TRISD = 0b00000000;					// set PORTD as OUTPUT
		 
	ANSEL = 0;						// Set PORTA as Digital I/O	for PIC16F887
	ANSELH = 0; 						// SET PORTB as DIGITAL I/O for PIC16F887

	
	//setup USART
	SPBRG = 0x81;						//set baud rate to 9600 for 20Mhz
	BRGH = 1;							//baud rate high speed option
	TXEN = 1;							//enable transmission
	CREN = 1;							//enable reception
	SPEN = 1;							//enable serial port
	TX9 =0;				//8-bit transmission
	RX9 =0;				//8-bit reception
	
	
	//setup ADC
	ADCON1 = 0b00000110;				//set ADx pin digital I/O
	
	//configure lcd
	send_config(0b00000001);			//clear display at lcd
	send_config(0b00000010);			//lcd return to home 
	send_config(0b00000110);			//entry mode-cursor increase 1
	send_config(0b00001100);			//display on, cursor off and cursor blink off
	send_config(0b00111000);			//function set
			
	
//infinity loop 

//uart_init();		
while(1)
	{
   	CREN=1;
	   	a = uart_rec(); 
		lcd_clr();		
		lcd_goto(0);
		send_string("The value is:");	
		lcd_goto(20);	
		send_char(a);

        CREN=0;	
		}
		
	}						

//===========================================================================
//	Functions
//===========================================================================

void delay(unsigned long data)			//delay function, the delay time
{										//depend on the given value
	for( ;data>0;data-=1);
}

void send_config(unsigned char data)	//send lcd configuration 
{
	rs=0;								//set lcd to configuration mode
	lcd_data=data;						//lcd data port = data
	e=1;								//pulse e to confirm the data
	delay(50);
	e=0;
	delay(50);
}

void send_char(unsigned char data)		//send lcd character
{
	rs=1;								//set lcd to display mode
	lcd_data=data;						//lcd data port = data
	e=1;								//pulse e to confirm the data
	delay(10);
	e=0;
	delay(10);
}

void lcd_goto(unsigned char data)		//set the location of the lcd cursor
{										//if the given value is (0-15) the 
 	if(data<16)							//cursor will be at the upper line
	{									//if the given value is (20-35) the 
	 	send_config(0x80+data);			//cursor will be at the lower line
	}									//location of the lcd cursor(2X16):
	else								// -----------------------------------------------------
	{									// | |00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15| |
	 	data=data-20;					// | |20|21|22|23|24|25|26|27|28|29|30|31|32|33|34|35| |
		send_config(0xc0+data);			// -----------------------------------------------------	
	}
}

void lcd_clr(void)						//clear the lcd
{
 	send_config(0x01);
	delay(600);	
}

void send_string(const char *s)			//send a string to display in the lcd
{          
	unsigned char i=0;
  	while (s && *s)send_char (*s++);

}

unsigned char uart_rec(void)			//receive uart value
{
	unsigned char rec_data;
	while(RCIF==0);						//wait for data
	rec_data = RCREG;				
	return rec_data;					//return the data received
}

void uart_send(unsigned char data)
{
while(TXIF==0); //only send the new data after
TXREG=data; //the previous data finish sent
}
 
void uart_str(const char *s)
{
while(*s)uart_send(*s++); // UART sending string
}

The VB code :

Imports System.IO.Ports
Public Class Form2

    Delegate Sub AddText(ByVal Text As String)
    Dim myEnc As System.Text.Encoding = System.Text.Encoding.GetEncoding(28591)

    Private Sub SerialPort1_DataReceived(ByVal sender As Object, _
                       ByVal e As SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
        Dim br As Integer = SerialPort1.BytesToRead
        If br > 0 Then
            Dim b(br - 1) As Byte
            br = SerialPort1.Read(b, 0, br)
            Dim s As String = myEnc.GetChars(b)
            RichTextBox1.Invoke(New AddText(AddressOf RichTextBox1.AppendText), s)
        End If
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If SerialPort1.IsOpen Then
            SerialPort1.Close()
        Else
            Try
                SerialPort1.PortName = "COM8"
                SerialPort1.BaudRate = 9600
                SerialPort1.Encoding = myEnc
                SerialPort1.Open()
                MsgBox("The port is open", MsgBoxStyle.Information)
            Catch ex As Exception
                MessageBox.Show(ex.ToString)
            End Try
        End If
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        SerialPort1.Write(TextBox1.Text)
  
    End Sub