[SOLVED] problem with displaying message on the LCD

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mariuszoll

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Hi,

I have to implement a serial communication via USART interface between 2 PICs(18F2620 and 18F4550). The transmitter has implemented a card reader application and a LCD. First, it reads the information from the card, and it sends it to the receiver. Depends on this information the receiver turns on some LEDs, and the receiver responds back with a message. I measured with the oscilloscope the signal on both the transmitter and the receiver sides and they are identical, but nothing is displayed on the LCD. I thought that there is a problem with the receiving part, and I tried to implement an ISR for EUSART receive part. The code is written in C, I use MPLAB, MCC18 compiler. Please find attached my code:

//Program

Code: 
/*     LCD 16x2
    4 bit mode
    RA7--> RS
    RA6-->Enable
    RW-->GND
    RC0..RC3 --> DB4 to DB7
    LCD: PC1602-H from PowerTip
    ST7066U_lcd_driver
    PIC18F2620  
    4MHz
*/

#include <p18f2620.h>
#include <delays.h>
#include <string.h>
#include <usart.h>

// Pragma

#pragma config WDT = OFF            // watch dog disabled
#pragma config OSC = INTIO67
#pragma config IESO = OFF            //Oscillator Switchover mode disabled
#pragma config XINST = OFF
#pragma config BOREN = OFF          //Brown-out Reset disabled in hardware and software
#pragma config PBADEN=OFF            //PORTB<4:0> pins are configured as digital I/O on Reset    
#pragma config STVREN=OFF            //Stack full/underflow will not cause Reset
#pragma config LVP=OFF                //Single-Supply ICSP disabled  
#pragma config MCLRE=ON                //MCLR pin enabled

//*****************************************************************************
//                            CONSTANT DEFINITION
//*****************************************************************************

# define databits LATC                // LCD 4 bit data PORT
# define data0 PORTBbits.RB4        // data0(green wire) of RFID tag
# define data1 PORTBbits.RB3        // data1(white wire) of RFID tag
# define btn1 PORTCbits.RC4            // button for save mode (active low)

//*****************************************************************************

// Variables

    char string[15]="Place your tag";
    char string1[15]="on the reader";
    char string2[10]="Save mode";
    char string3[7]="Id no:";
    char string4[16]="User identified";
    char string5[15]="User ID saved";
    char string6[20]="User not found";
    char txarray[9]="";
    char rxarray[23]="";
    char receive[22]="";
    int i=0,q,m=0;
    unsigned char rxchar,r=0,flag=0, icount=0,check=0;
    
void high_isr(void);

/****** High priority interrupt vector ******/
#pragma code high_vector=0x08

void interrupt_at_high_vector(void)
{
  _asm GOTO high_isr _endasm
}

#pragma code

/********** High priority ISR **************/
#pragma interrupt high_isr

void high_isr(void)
{
    if(PIR1bits.RCIF)
    {
        if(RCSTAbits.FERR==1)
        {
            rxchar=RCREG;
            RCSTAbits.CREN=0;
            RCSTAbits.CREN=1;
        }

        if(RCSTAbits.OERR==1)
        {
            rxchar=RCREG;
            RCSTAbits.CREN=0;
            RCSTAbits.CREN=1;
        }

        rxchar=RCREG;
        rxarray[r]=rxchar;
        r++;
            
        if(rxchar=='\r') // if the character is Enter flag is put on 1
        {
            flag=1;
        }

        check=1;    
    }
    PIR1bits.RCIF=0;
}

/** L O C A L   F U N C T I O N S  *******************************************/

void set_hi_nibble(unsigned char data)        // output hi nibble data on port lines
{
    unsigned char temp=LATC;

    temp= temp & 0xF0;
    temp= temp | (data>>4);
    LATC=temp;
}

void set_lo_nibble(unsigned char data)        // output low nibble data on port lines
{
    unsigned char temp=LATC;

    temp= temp & 0xF0;
    temp= temp | (data & 0x0F);
    LATC=temp;
}

void en_set(void)            //function used to set Enable signal properly
{
    PORTAbits.RA6 = 1;        // Set EN on 1
    Delay1KTCYx(1);
    PORTAbits.RA6 = 0;        // Set EN on 0
}

void send_char(unsigned char c)
{
    LATAbits.LATA7=1;        // set RS on 1
    set_hi_nibble(c);
    en_set();
    Delay1KTCYx(5);            // delay 50ms

    set_lo_nibble(c);
    en_set();
    Delay1KTCYx(5);            // delay 5ms
}

void cmd(unsigned char c)
{
    LATAbits.LATA7=0;        // set RS on 0

    set_hi_nibble(c);
    en_set();
    Delay1KTCYx(5);            // delay 50ms

    set_lo_nibble(c);
    en_set();
    Delay1KTCYx(5);            // delay 5ms
}

void InitUART(void)
{
    TXSTAbits.TX9=0;
    TXSTAbits.TXEN=1;
    TXSTAbits.SYNC=0;
    TXSTAbits.BRGH=1;
    TXSTAbits.TX9D=0;
    RCSTAbits.SPEN=1;
    BAUDCONbits.BRG16=0;
    SPBRG=25;                // 9600KBaud

    // receive config
    RCSTAbits.RX9=0;
    RCSTAbits.CREN=1;
    RCSTAbits.RX9D=0;
}

void LCDInit(void)
{
     Delay10KTCYx(20);        //Delay 200ms

    LATA=0;
    LATC=0;

    //Outputs
    TRISAbits.TRISA7=0;        //RS signal
    TRISAbits.TRISA6=0;        //EN signal
    
    TRISCbits.TRISC0=0;        // RC0 output, DB4
    TRISCbits.TRISC1=0;        // RC1 output, DB5
    TRISCbits.TRISC2=0;        // RC2 output, DB6
    TRISCbits.TRISC3=0;        // RC3 output, DB7
    TRISCbits.TRISC5=0;        // STATUS LED
    TRISCbits.TRISC6=0;        // UART_TX

    //Inputs
    TRISBbits.TRISB4=1;        //data0
    TRISBbits.TRISB3=1;        //data1
    TRISCbits.TRISC4=1;        // button
    TRISCbits.TRISC7=1;        //UART_RX
    
    // Oscillator frequency
    OSCCON=0b01100111;        // 4MHz

    // pins configurred as digital
    ADCON1=0b00001111;

    // Interrupt config
    INTCON=0x40;                   // PEIE high
    IPR1bits.RCIP=1;                // EUSART Receive Interrupt High Priority
    RCONbits.IPEN=1;            // enable priority levels
    PIE1bits.RCIE=1;            // Enable EUSART receive interrupt

    LATAbits.LATA6=0;        // Set En on 0
    Delay1KTCYx(100);        //Delay 100ms
    
    LATAbits.LATA7=0;        // Set RS on 0
    Delay1KTCYx(15);        //Delay 15ms

    LATC=0x3;
    en_set();
    Delay1KTCYx(5);            // delay 5ms

    LATC=0x3;
    en_set();
    Delay100TCYx(1);        // delay 100us

    LATC=0x3;
    en_set();
    Delay10TCYx(4);            // delay 40us

    LATC=0x2;
    en_set();
    Delay10TCYx(4);            // delay 40us

    //Function set

    cmd(0x28);            // 4 bits, 2 lines, 5x7 dots format display mode
    Delay10TCYx(4);        // delay 40us

    //Display ON control

    cmd(0x0E);            // display on, cursor on, blinking cursor position off
    Delay10TCYx(4);        // delay 40us

    //Clear Display

    cmd(0x01);            // dispaly clear
    Delay1KTCYx(2);        // delay 2ms

    //Entry set increment

    cmd(0x06);            // increment, shift right
    Delay100TCYx(10);    // delay 1ms

}

void putch(unsigned char byte)
{
    while(!TXSTAbits.TRMT);
    TXREG=byte;
}

void send_dec_lcd(unsigned long data,unsigned char num_dig)        //convert binary number and display number in decimal
{
    if(num_dig>=10)                                            
    {
        data=data%10000000000;
        send_char(data/1000000000+0x30);
        txarray[i]=data/1000000000+0x30;
        i++;
    }    
    if(num_dig>=9)
    {
        data=data%1000000000;
        send_char(data/100000000+0x30);
        txarray[i]=data/100000000+0x30;
        i++;
    }    
    if(num_dig>=8)
    {
        data=data%100000000;
        send_char(data/10000000+0x30);
        txarray[i]=data/10000000+0x30;
        i++;
    }    
    if(num_dig>=7)
    {
        data=data%10000000;
        send_char(data/1000000+0x30);
        txarray[i]=data/1000000+0x30;
        i++;
    }    
    if(num_dig>=6)
    {
        data=data%1000000;
        send_char(data/100000+0x30);
        txarray[i]=data/100000+0x30;
        i++;
    }    
    if(num_dig>=5)
    {
        data=data%100000;
        send_char(data/10000+0x30);
        txarray[i]=data/10000+0x30;
        i++;
    }    
    if(num_dig>=4)
    {
        data=data%10000;
        send_char(data/1000+0x30);
        txarray[i]=data/1000+0x30;
        i++;
    }
    if(num_dig>=3)
    {
        data=data%1000;
        send_char(data/100+0x30);
        txarray[i]=data/100+0x30;
        i++;
    }
    if(num_dig>=2)
    {
        data=data%100;
        send_char(data/10+0x30);
        txarray[i]=data/10+0x30;
        i++;
    }
    if(num_dig>=1)
    {
        data=data%10;
        send_char(data+0x30);
        txarray[i]=data+0x30;
        i++;
    }
}

void send_dec_usart(void)        //convert binary number and display number in decimal
{
    txarray[8]='\r';
    q=0;
    while(q<=8)
    {
        putch(txarray[q]);
        q++;
    }    
}

void lcd_goto(unsigned char data)                        //set the location of the lcd cursor
{
     if(data<16)                                            //if the given value is (0-15) the
    {                                                    //cursor will be at the upper line
         cmd(0x80+data);
    }
    else                                                //if the given value is (20-35) the
    {                                                    //cursor will be at the lower line
         data=data-20;                                    //location of the lcd cursor(2X16):
        cmd(0xC0+data);                                    // -----------------------------------------------------
    }                                                    // | |00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15| |
}                                                        // | |20|21|22|23|24|25|26|27|28|29|30|31|32|33|34|35| |
                                                        // -----------------------------------------------------
void lcd_string(const char *s)
{
    while(*s)
        {
        //    Delay1KTCYx(10);    //Delay 10ms
            send_char(*s++);
        }
}

void writeString(const char *s)
{
    while(*s)
    {
        while(!TXSTAbits.TRMT);
        TXREG=*s;
        s++;
    }
}

/********************************************************************/
/*                 Read the string from the USART interface            */
/********************************************************************/
void interrupt(void)
{
    if(PIR1bits.RCIF)
    {
        if(RCSTAbits.FERR==1)
        {
            rxchar=RCREG;
            RCSTAbits.CREN=0;
            RCSTAbits.CREN=1;
        }

        if(RCSTAbits.OERR==1)
        {
            rxchar=RCREG;
            RCSTAbits.CREN=0;
            RCSTAbits.CREN=1;
        }

        rxchar=RCREG;
        rxarray[r]=rxchar;
        r++;
            
        if(rxchar=='\r') // if the character is Enter flag is put on 1
        {
            flag=1;
        }
    }
    PIR1bits.RCIF=0;
}
///////////////////functia main///////////////////////////////////////////

void main()
{
    unsigned char i,repeat,a,b,database;
    unsigned char data[26];
    unsigned char convert1=0;
    unsigned int convert2=0;
    unsigned mode=0;
    unsigned char id1[2]={127,0};
    unsigned int id2[2]={22449,0};

    //Initializations
    PORTC=0x00;
    LCDInit();
    InitUART();
    id1[1]=0;
    id2[1]=0;
    i=0;
    database=0;
    check=0;
    jump:;

    convert1=0;                // clear convert1
    convert2=0;                // clear convert2
    cmd(0x01);              // clear lcd
    lcd_goto(0);            // 1st row, set cursor at location 0
    lcd_string(string);
    lcd_goto(20);            // 2nd row    
    lcd_string(string1);    // "on the reader"

    while(mode==0)        // no RFID tag is placed on RFID reader
    {
        if((data0==0)||(data1==0)) mode=1;    // RFID tag is placed on the reader (receive data stream from RFID tag)
        else if (btn1==0) mode=2;            // push button is pressed, enter to save mode
    }

    // RFID tag is placed on the reader (RFID reader receive data stream from RFID tag)
    while(mode==1)
    {
        if((data0==0)&&(data1==1))                // if data0 changes(data0 active low)
        {
            data[i]=0;                            // save the bit received as 0
            while((data0==0)&&(data1==1));        // wait until data0 changes to high logic
        }
        else if((data0==1)&&(data1==0))                // if data1 changes(data1 active low)
        {
            data[i]=1;                            // save the bit received as 1
            while((data0==1)&&(data1==0));        // wait until data1 changes to high logic
        }

        i++;
        
        while(i<26)                                // repeat the loop until all 26 bit data are sent(start from 0 to 25)
        {
            while((data0==1)&&(data1==1));        // wait for data
            if((data0==0)&&(data1==1))
            {
                data[i]=0;                            // save the bit received as 0
                while((data0==0)&&(data1==1));        // wait until data0 changes to high logic
            }
            else if((data0==1)&&(data1==0))                // if data1 changes(data1 active low)
            {
            data[i]=1;                            // save the bit received as 1
            while((data0==1)&&(data1==0));        // wait until data1 changes to high logic
            }
            i++;
        }
        mode=0;            // after all data are sent, reset as no RFID tag is placed on RFID reader
        i=0;            // clear i
        cmd(0x01);        // lcd clear
                    
        for(i=0; i<8; i++)            // loop for data[0]-data[7]
        {
            convert1=(convert1<<1) | data[i+1];  // shift current data and combine with previous datra, store in convert1
        }
        for(i=0; i<16; i++)            // loop for data[8]-data[25]
        {
            convert2=(convert2<<1) | data[i+9];    // shift current data and combine with previous datra, store in convert2
        }
        for(b=0; b<2; b++)            // compare with id[0] and id[1]
        {
            if((convert1==id1[b])&&(convert2==id2[b])) database=1;    // id match, set database to 1
        }
        cmd(0x01);                    // clear lcd
    }

    // push button is pressed, enter to save mode
    while(mode==2)
    {
        cmd(0x01);                          // clear lcd
        lcd_goto(0);                        // 1st row, set cursor to location 0
        lcd_string(string2);                // display "Save mode"
        Delay1KTCYx(2);
        lcd_goto(20);                        // 2nd row
        lcd_string(string);                    // display " Place your tag"
    
        while(i<26)
        {
            while((data0==1)&&(data1==1));    // wait for data
            if((data0==0)&&(data1==1))
            {
                data[i]=0;                            // save the bit received as 0
                while((data0==0)&&(data1==1));        // wait until data0 changes to high logic
            }
            else if((data0==1)&&(data1==0))                // if data1 changes(data1 active low)
            {
            data[i]=1;                            // save the bit received as 1
            while((data0==1)&&(data1==0));        // wait until data1 changes to high logic
            }
            i++;
        }
        mode=0;            // after all data are sent, reset as no RFID tag is placed on RFID reader
        i=0;            // clear i
        cmd(0x01);        // lcd clear

        for(i=0; i<8; i++)            // loop for data[0]-data[7]
        {
            convert1=(convert1<<1) | data[i+1];  // shift current data and combine with previous datra, store in convert1
        }
        for(i=0; i<16; i++)            // loop for data[8]-data[25]
        {
            convert2=(convert2<<1) | data[i+9];    // shift current data and combine with previous datra, store in convert2
        }
        id1[1]=convert1;
        id2[1]=convert2;

        database=2;                    // display id no. and "User ID saved"
        cmd(0x01);                    // clear lcd
    }

    switch(database)
    {
        case 1:                                        // id1 match
                PORTCbits.RC5=0;                    // STATUS LED OFF
                lcd_goto(0);                        // 1st row, set cursor to location 0
                lcd_string(string3);                // display "Id no:"
                lcd_goto(7);                        // 1st row, set cursor to location 7
                send_dec_lcd(convert1,3);            // display convert1 in 3 decimal number
                lcd_goto(10);                        // 1st row, set cursor to location 10
                send_dec_lcd(convert2,5);            // display convert2 in 5 decimal number
                send_dec_usart();
                lcd_goto(20);                        // 2nd row, set cursor to location 20
                lcd_string(string4);                // display "User identified"
                Delay10KTCYx(100);                    // delay 1s
                break;
            
        case 2:                                        // save id
                lcd_goto(0);                        // 1st row, set cursor to location 0
                lcd_string(string3);                // display "Id no:"
                lcd_goto(7);                        // 1st row, set cursor to location 7
                send_dec_lcd(convert1,3);            // display convert1 in 3 decimal number
                lcd_goto(10);                        // 1st row, set cursor to location 10
                send_dec_lcd(convert2,5);            // display convert2 in 5 decimal number
                lcd_goto(20);                        // 2nd row, set cursor to location 20
                lcd_string(string5);                // display "User ID saved"
                Delay10KTCYx(100);                    // delay 1s
                goto jump;
                break;
            
        default:                                    // id doesn't match
                PORTCbits.RC5=1;                    // STATUS LED ON
                lcd_goto(0);                        // 1st row, set cursor to location 0
                lcd_string(string3);                // display "Id no:"
                lcd_goto(7);                        // 1st row, set cursor to location 7
                send_dec_lcd(convert1,3);            // display convert1 in 3 decimal number
                lcd_goto(10);                        // 1st row, set cursor to location 10
                send_dec_lcd(convert2,5);            // display convert2 in 5 decimal number
                lcd_goto(20);                        // 2nd row, set cursor to location 20
                lcd_string(string6);                // display "User not found"
                Delay10KTCYx(100);                    // delay 1s  
                goto jump;
                break;

    }
        
    Delay10KTCYx(100);                    // delay 1s
    i=0;
    database=0;
    convert1=0;
    convert2=0;
    check=0;

    while(1)
    {
        if(flag==1)
        {
            flag=0;
            r=0;
        }
    
        if(check==1)
        {
            if(strncmppgm2ram(rxarray,"ok",2)==0)
            {
                cmd(0x01);                            // clear the display
                lcd_goto(0);                        // 1st row, set cursor to location 0
                for(i=0;i<2;i++)
                {
                    send_char(rxarray[i]);
                    Delay10TCYx(5);
                }
            }
            else
            {
                if (strncmppgm2ram(rxarray,"previous box",12)==0)
                {
                    cmd(0x01);                            // clear the display
                    lcd_goto(0);                        // 1st row, set cursor to location 0
                    for(i=0;i<12;i++)
                    {
                        send_char(rxarray[i]);
                        Delay10TCYx(5);
                    }
                }
            }
            check=0;
        }
    }// while(1)
}//main

Thank you in advance.
 
Last edited by a moderator:

post your c file as it is hard to read your code!
And if it is one file its not a good practice to write all your project code in one !
 

The message which is received is not accurate displayed on the LCD from time to time, it looks like an overwritten. I measured with the oscilloscope the EN, and RS signals in the overwritten case and they are active with a certain frequency. Below is attached the code from the receiver board:
//Program

Code: 
/* 	LCD 16x2
	4 bit mode
	RA7--> RS
	RA6-->Enable
	RW-->GND
	RC0..RC3 --> DB4 to DB7
	LCD: PC1602-H from PowerTip
	ST7066U_lcd_driver
	PIC18F2620  
	4MHz
*/

#include <p18f2620.h>
#include <delays.h>
#include <string.h>
#include <usart.h>

// Pragma

#pragma config WDT = OFF			// watch dog disabled
#pragma config OSC = INTIO67
#pragma config IESO = OFF			//Oscillator Switchover mode disabled 
#pragma config XINST = OFF
#pragma config BOREN = OFF  		//Brown-out Reset disabled in hardware and software 
#pragma config PBADEN=OFF			//PORTB<4:0> pins are configured as digital I/O on Reset    
#pragma config STVREN=OFF			//Stack full/underflow will not cause Reset 
#pragma config LVP=OFF				//Single-Supply ICSP disabled  
#pragma config MCLRE=ON				//MCLR pin enabled

//*****************************************************************************
//                            CONSTANT DEFINITION
//*****************************************************************************

# define databits LATC				// LCD 4 bit data PORT
# define data0 PORTBbits.RB4		// data0(green wire) of RFID tag
# define data1 PORTBbits.RB3		// data1(white wire) of RFID tag
# define btn1 PORTCbits.RC4			// button for save mode (active low)

//*****************************************************************************

// Variables

	char rxarray[23]="";
	char receive[2]="ok";
	int i=0,q,m=0;
	unsigned char rxchar="",r=0,flag=0, icount=0,check=0;
	

/** L O C A L   F U N C T I O N S  *******************************************/

void set_hi_nibble(unsigned char data)		// output hi nibble data on port lines
{
	unsigned char temp=LATC;

	temp= temp & 0xF0;
	temp= temp | (data>>4);
	LATC=temp;
}

void set_lo_nibble(unsigned char data)		// output low nibble data on port lines
{
	unsigned char temp=LATC;

	temp= temp & 0xF0;
	temp= temp | (data & 0x0F);
	LATC=temp;
}

void en_set(void)			//function used to set Enable signal properly
{
	LATAbits.LATA6 = 1;		// Set EN on 1
	Delay1KTCYx(1);
	LATAbits.LATA6 = 0;		// Set EN on 0
}

void send_char(unsigned char c)
{
	LATAbits.LATA7=1;		// set RS on 1
	set_hi_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 50ms

	set_lo_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 5ms
}

void cmd(unsigned char c)
{
	LATAbits.LATA7=0;		// set RS on 0

	set_hi_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 50ms

	set_lo_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 5ms
}

void InitUART(void)
{
	TXSTAbits.TX9=0;
	TXSTAbits.TXEN=1;
	TXSTAbits.SYNC=0;
	TXSTAbits.BRGH=1;
	TXSTAbits.TX9D=0;
	RCSTAbits.SPEN=1;
	BAUDCONbits.BRG16=0;
	SPBRG=25;				// 9600KBaud

	// receive config
	RCSTAbits.RX9=0;
	RCSTAbits.CREN=1;
	RCSTAbits.RX9D=0; 
}

void LCDInit(void)
{
 	Delay10KTCYx(20);		//Delay 200ms

	LATA=0;
	LATC=0;

	//Outputs
	TRISAbits.TRISA7=0;		//RS signal
	TRISAbits.TRISA6=0;		//EN signal
	
	TRISCbits.TRISC0=0;		// RC0 output, DB4
	TRISCbits.TRISC1=0;		// RC1 output, DB5
	TRISCbits.TRISC2=0;		// RC2 output, DB6
	TRISCbits.TRISC3=0;		// RC3 output, DB7
	TRISCbits.TRISC5=0;		// STATUS LED
	TRISCbits.TRISC6=0;		// UART_TX

	//Inputs
	TRISBbits.TRISB4=1;		//data0
	TRISBbits.TRISB3=1;		//data1
	TRISCbits.TRISC4=1;		// button
	TRISCbits.TRISC7=1;		//UART_RX
	
	// Oscillator frequency
	OSCCON=0b01100111;		// 4MHz

	// pins configurred as digital
	ADCON1=0b00001111;

	// Interrupt config
	INTCON=0x40;       			// PEIE activated
//	IPR1bits.RCIP=1;        	// EUSART Receive Interrupt High Priority
//	RCONbits.IPEN=1;			// enable priority levels
	PIE1bits.RCIE=1;			// Enable EUSART receive interrupt

	LATAbits.LATA6=0;		// Set En on 0
	Delay1KTCYx(100);		//Delay 100ms
	
	LATAbits.LATA7=0;		// Set RS on 0
	Delay1KTCYx(15);		//Delay 15ms

	LATC=0x3;
	en_set();
	Delay1KTCYx(5);			// delay 5ms

	LATC=0x3;
	en_set();
	Delay100TCYx(1);		// delay 100us

	LATC=0x3;
	en_set();
	Delay10TCYx(4);			// delay 40us

	LATC=0x2;
	en_set();
	Delay10TCYx(4);			// delay 40us

	//Function set

	cmd(0x28);			// 4 bits, 2 lines, 5x7 dots format display mode
	Delay10TCYx(4);		// delay 40us

	//Display ON control

	cmd(0x0E);			// display on, cursor on, blinking cursor position off
	Delay10TCYx(4);		// delay 40us

	//Clear Display

	cmd(0x01);			// dispaly clear
	Delay1KTCYx(2);		// delay 2ms

	//Entry set increment

	cmd(0x06);			// increment, shift right
	Delay100TCYx(10);	// delay 1ms

}

void putch(unsigned char byte)
{
	while(!TXSTAbits.TRMT);
	TXREG=byte;
}

void lcd_goto(unsigned char data)						//set the location of the lcd cursor
{
 	if(data<16)											//if the given value is (0-15) the 
	{													//cursor will be at the upper line
	 	cmd(0x80+data);
	}
	else												//if the given value is (20-35) the 
	{													//cursor will be at the lower line
	 	data=data-20;									//location of the lcd cursor(2X16):
		cmd(0xC0+data);									// -----------------------------------------------------
	}													// | |00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15| |
}														// | |20|21|22|23|24|25|26|27|28|29|30|31|32|33|34|35| |
														// -----------------------------------------------------
void lcd_string(const char *s)
{
	while(*s)
		{
		//	Delay1KTCYx(10);	//Delay 10ms
			send_char(*s++);
		}
}

void writeString(const char *s)
{
	while(*s)
	{
		while(!TXSTAbits.TRMT);
		TXREG=*s;
		s++;
	}
}

/********************************************************************/
/*	 			Read the string from the USART interface			*/
/********************************************************************/
void interrupt(void)
{
	if(PIR1bits.RCIF)
	{
		if(RCSTAbits.FERR==1)
		{
			rxchar=RCREG;
			RCSTAbits.CREN=0;
			RCSTAbits.CREN=1;
		}

		if(RCSTAbits.OERR==1)
		{
			rxchar=RCREG;
			RCSTAbits.CREN=0;
			RCSTAbits.CREN=1;
		}

		rxchar=RCREG;
		if(rxchar!=0)
		{
			rxarray[r]=rxchar;
			r++;
		}
			
		if(rxchar=='\r') // if the character is Enter flag is put on 1
		{
			flag=1;
		}
	}
	PIR1bits.RCIF=0;
}
///////////////////functia main///////////////////////////////////////////

void main()
{
	

	//Initializations
	PORTC=0x00;
	LCDInit();
	InitUART();
	 
	check=0;
	r=0;

	while(1)
	{	
		cmd(0x01);		// clear the LCD
		lcd_goto(0);	// 1st row, set cursor to location 0

		interrupt();
		if(flag==1)
		{
			flag=0;
			r=0;
		} 
		
		if(strncmppgm2ram(rxarray,"ok",2)==0)
		{
			check=1;
		} 
			
		else
		{
			if (strncmppgm2ram(rxarray,"previous box",12)==0)
			{
				check=2;
			}
				
		} 

		switch(check)
		{

			case 1:
				//	cmd(0x01);							// clear the display
					lcd_goto(0);						// 1st row, set cursor to location 0
				/*	for(i=0;i<2;i++)
					{
						send_char(rxarray[i]);
					//	Delay10TCYx(5);
					} */
					lcd_string(receive);
					Delay1KTCYx(1);
					break;

			case 2:
					cmd(0x01);							// clear the display
					lcd_goto(0);						// 1st row, set cursor to location 0
					for(i=0;i<12;i++)
					{
						send_char(rxarray[i]);
					//	Delay10TCYx(5);
					}
					break;

			default: break;
		} 

/*	if(strncmppgm2ram(rxarray,"ok",2)==0)
		{
			cmd(0x01);							// clear the display
			lcd_goto(0);						// 1st row, set cursor to location 0
			for(i=0;i<2;i++)
			{
				send_char(rxarray[i]);
			//	Delay10TCYx(5);
			} 
			
		}
		else
		{
			if (strncmppgm2ram(rxarray,"previous box",12)==0)
			{
				cmd(0x01);							// clear the display
				lcd_goto(0);						// 1st row, set cursor to location 0
				for(i=0;i<12;i++)
				{
					send_char(rxarray[i]);
				//	Delay10TCYx(5);
				}
			}
				
		} */
		
	}// while(1)
}//main


Could you help me please to fix it?

Thank you in advance.
 
Last edited by a moderator:

here is the C code of my project.
 

Attachments

  • wiegand_2620.zip
    3.9 KB · Views: 102

The messages that I want to send are defined in the following way at the transmitter side:

Code: 
char string1[3]="ok";
char string2[11]="time is up";
 
void display_ok(void)
{
    for(k=0; k<strlen(string1); k++)
        { WriteUSART(string1[k]);
          while(!TXSTAbits.TRMT);
        }
    TXREG='\r';
}
 
void display_nok_time(void)
{
    for(k=0; k<strlen(string2); k++)
        { WriteUSART(string2[k]);
          while(!TXSTAbits.TRMT);
        }
    TXREG='\r';
}
and the initialization for USART interface is:
void init_UART(void)
{
    TXSTAbits.TX9=0;
    TXSTAbits.TXEN=1;
    TXSTAbits.SYNC=0;
    TXSTAbits.BRGH=1;
    TXSTAbits.TX9D=0;
    RCSTAbits.SPEN=1;
    BAUDCONbits.BRG16=0;
    SPBRG=25;            // 9600KBaud

    // added for reading from keyboard

    RCSTAbits.RX9=0;
    RCSTAbits.CREN=1;
    RCSTAbits.RX9D=0;
}
Attached is the code of the receiver board. I verified it with the PC and everything works well, but when I connected back in my setup the LCD doesn't display any character.

- - - Updated - - -

Here is attached the code from the receiver board, used to display the messages sent by the transmitter board.
 

Attachments

  • Program.doc
    44 KB · Views: 111
Last edited by a moderator:

In general my software works, but I have to implement the case when for instance the transmitter sends almost in the same time both messages "OK", and "time is up". I treated the frame error case and overrun error case, but on the display is shown only one message. I have a data corruption problem.
Could you help me please to fix this problem?
Please find attached my code:

LCD 16x2
4 bit mode
RA7--> RS
RA6-->Enable
RW-->GND
RC0..RC3 --> DB4 to DB7
LCD: PC1602-H from PowerTip
ST7066U_lcd_driver
PIC18F2620
4MHz

Code: 
#include <p18f2620.h>
#include <delays.h>
#include <string.h>
#include <usart.h>

// Pragma

#pragma config WDT = OFF			// watch dog disabled
#pragma config OSC = INTIO67
#pragma config IESO = OFF			//Oscillator Switchover mode disabled 
#pragma config XINST = OFF
#pragma config BOREN = OFF  		//Brown-out Reset disabled in hardware and software 
#pragma config PBADEN=OFF			//PORTB<4:0> pins are configured as digital I/O on Reset    
#pragma config STVREN=OFF			//Stack full/underflow will not cause Reset 
#pragma config LVP=OFF				//Single-Supply ICSP disabled  
#pragma config MCLRE=ON				//MCLR pin enabled

//*****************************************************************************
//                            CONSTANT DEFINITION
//*****************************************************************************

# define databits LATC				// LCD 4 bit data PORT
# define data0 PORTBbits.RB4		// data0(green wire) of RFID tag
# define data1 PORTBbits.RB3		// data1(white wire) of RFID tag
# define btn1 PORTCbits.RC4			// button for save mode (active low)

//*****************************************************************************

// Variables

	char txarray[9]="";
	char rxarray[23]="";
	char msg[23]="";
	int i=0,q,m=0;
	unsigned char rxchar="",r=0,flag=0, icount=0,check=0,col,row;
	

/** L O C A L   F U N C T I O N S  *******************************************/

void set_hi_nibble(unsigned char data)		// output hi nibble data on port lines
{
	unsigned char temp=LATC;

	temp= temp & 0xF0;
	temp= temp | (data>>4);
	LATC=temp;
}

void set_lo_nibble(unsigned char data)		// output low nibble data on port lines
{
	unsigned char temp=LATC;

	temp= temp & 0xF0;
	temp= temp | (data & 0x0F);
	LATC=temp;
}

void en_set(void)			//function used to set Enable signal properly
{
	LATAbits.LATA6 = 1;		// Set EN on 1
	Delay1KTCYx(1);
	LATAbits.LATA6 = 0;		// Set EN on 0
}

void send_char(unsigned char c)
{
	LATAbits.LATA7=1;		// set RS on 1
	set_hi_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 5ms

	set_lo_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 5ms
}

void cmd(unsigned char c)
{
	LATAbits.LATA7=0;		// set RS on 0

	set_hi_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 50ms

	set_lo_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 5ms
}

void InitUART(void)
{
	TXSTAbits.TX9=0;
	TXSTAbits.TXEN=1;
	TXSTAbits.SYNC=0;
	TXSTAbits.BRGH=1;
	TXSTAbits.TX9D=0;
	RCSTAbits.SPEN=1;
	BAUDCONbits.BRG16=0;
	SPBRG=25;				// 9600KBaud

	// receive config
	RCSTAbits.RX9=0;
	RCSTAbits.CREN=1;
	RCSTAbits.RX9D=0; 
}

void LCDInit(void)
{
 	Delay10KTCYx(20);		//Delay 200ms

	LATA=0;
	LATC=0;

	//Outputs
	TRISAbits.TRISA7=0;		//RS signal
	TRISAbits.TRISA6=0;		//EN signal
	
	TRISCbits.TRISC0=0;		// RC0 output, DB4
	TRISCbits.TRISC1=0;		// RC1 output, DB5
	TRISCbits.TRISC2=0;		// RC2 output, DB6
	TRISCbits.TRISC3=0;		// RC3 output, DB7
	TRISCbits.TRISC5=0;		// STATUS LED
	TRISCbits.TRISC6=0;		// UART_TX

	//Inputs
	TRISBbits.TRISB4=1;		//data0
	TRISBbits.TRISB3=1;		//data1
	TRISCbits.TRISC4=1;		// button
	TRISCbits.TRISC7=1;		//UART_RX
	
	// Oscillator frequency
	OSCCON=0b01100111;		// 4MHz

	// pins configurred as digital
	ADCON1=0b00001111;

	// Interrupt config
	INTCON=0x40;       			// PEIE activated
//	IPR1bits.RCIP=1;        	// EUSART Receive Interrupt High Priority
//	RCONbits.IPEN=1;			// enable priority levels
	PIE1bits.RCIE=1;			// Enable EUSART receive interrupt

	LATAbits.LATA6=0;		// Set En on 0
	Delay1KTCYx(100);		//Delay 100ms
	
	LATAbits.LATA7=0;		// Set RS on 0
	Delay1KTCYx(15);		//Delay 15ms

	LATC=0x3;
	en_set();
	Delay1KTCYx(5);			// delay 5ms

	LATC=0x3;
	en_set();
	Delay100TCYx(1);		// delay 100us

	LATC=0x3;
	en_set();
	Delay10TCYx(4);			// delay 40us

	LATC=0x2;
	en_set();
	Delay10TCYx(4);			// delay 40us

	//Function set

	cmd(0x28);			// 4 bits, 2 lines, 5x7 dots format display mode
	Delay10TCYx(4);		// delay 40us

	//Display ON control

	cmd(0x0E);			// display on, cursor on, blinking cursor position off
	Delay10TCYx(4);		// delay 40us

	//Clear Display

	cmd(0x01);			// dispaly clear
	Delay1KTCYx(2);		// delay 2ms

	//Entry set increment

	cmd(0x06);			// increment, shift right
	Delay100TCYx(10);	// delay 1ms

}

void putch(unsigned char byte)
{
	while(!TXSTAbits.TRMT);
	TXREG=byte;
}

void lcd_goto(unsigned char data)						//set the location of the lcd cursor
{
 	if(data<16)											//if the given value is (0-15) the 
	{													//cursor will be at the upper line
	 	cmd(0x80+data);
	}
	else												//if the given value is (20-35) the 
	{													//cursor will be at the lower line
	 	data=data-20;									//location of the lcd cursor(2X16):
		cmd(0xC0+data);									// -----------------------------------------------------
	}													// | |00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15| |
}														// | |20|21|22|23|24|25|26|27|28|29|30|31|32|33|34|35| |
														// -----------------------------------------------------
void lcd_string(const char *s)
{
	while(*s)
		{
		//	Delay1KTCYx(10);	//Delay 10ms
			send_char(*s++);
		}
}

void writeString(const char *s)
{
	while(*s)
	{
		while(!TXSTAbits.TRMT);
		TXREG=*s;
		s++;
	}
}

///////////////////main///////////////////////////////////////////

void main()
{
	

	//Initializations
	PORTC=0x00;
	LCDInit();
	InitUART();
	 
	flag=0;
	r=0;
	col=0;
	row=1;
	cmd(0x01);

	while(1)
	{	
		if(PIR1bits.RCIF==1)
		{
			if(RCSTAbits.FERR==1)		// frame eror
			{
				rxchar=ReadUSART();
				RCSTAbits.CREN=0;
				RCSTAbits.CREN=1;
			}

			if(RCSTAbits.OERR==1)		// overrun error
			{
				rxchar=ReadUSART();
				RCSTAbits.CREN=0;
				RCSTAbits.CREN=1;
			}

			rxchar=ReadUSART();
			PIR1bits.RCIF=0;

			if(rxchar!='\r')
			{
				rxarray[r]=rxchar;
				msg[r]=rxarray[r];
				r++;
				col++;
				flag=0;
			}
			if(rxchar=='\r')
			{
				m=r-1;
				r=0;
				col=0;
				row=1;
				flag=1;
				for(i=0; i<strlen(rxarray); i++) rxarray[i]='\0';
				cmd(0x01);
			}
			if(flag==1)
			{
				for(i=0; i<=m; i++)
				{
					col=i;

					if(col<16 && row==1)
					{
				 		lcd_goto(0+col);
					}

					if(col>=16 && row==1)
					{
						col=0;
						row=2;
						lcd_goto(20+col);
					}
											
					send_char(msg[i]);
					Delay10KTCYx(3);
					col++;
				}
			}
		}

					
	}// while(1)
}//main
 
Last edited:

@mariuszoll: Why are you ignoring the suggestions of using the CODE tag for posting code segment ? Pasting the code in cleared text format is unreadable ..Personally, i dont even want to read your code like this. I have no idea, where one branch begins and ends... Edit your posts, put the code in the tag !
 

Could you give me please some ideas how can I fix this data corruption problem?

Thank you.
 

Try to isolate the issue. Write a test app where you output char by char on the screen and see if that works.
If i got it right, lcd_goto does not work properly ?
 

Unfortunately, I have never used interrupt service routine.
If you can, could help me please with this?

Thank you.
 

Here is my project file attached.

- - - Updated - - -

I made a test app, where I read char-by-char from Hyperterminal, and then I display on the LCD. In my opinion, it works as expected.
lcd_goto() routine works.
Please find below the code:

Code: 
#include <p18f2620.h>
#include <delays.h>
#include <string.h>
#include <usart.h>

// Pragma

#pragma config WDT = OFF			// watch dog disabled
#pragma config OSC = INTIO67
#pragma config IESO = OFF			//Oscillator Switchover mode disabled 
#pragma config XINST = OFF
#pragma config BOREN = OFF  		//Brown-out Reset disabled in hardware and software 
#pragma config PBADEN=OFF			//PORTB<4:0> pins are configured as digital I/O on Reset    
#pragma config STVREN=OFF			//Stack full/underflow will not cause Reset 
#pragma config LVP=OFF				//Single-Supply ICSP disabled  
#pragma config MCLRE=ON				//MCLR pin enabled

//*****************************************************************************
//                            CONSTANT DEFINITION
//*****************************************************************************

# define databits LATC				// LCD 4 bit data PORT
# define data0 PORTBbits.RB4		// data0(green wire) of RFID tag
# define data1 PORTBbits.RB3		// data1(white wire) of RFID tag
# define btn1 PORTCbits.RC4			// button for save mode (active low)

//*****************************************************************************

// Variables

	char txarray[9]="";
	char rxarray[23]="";
	char string[23]="";
	int i=0,q,m=0;
	unsigned char rxchar="",r=0,flag=0, icount=0,check=0,col,row;
	

/** L O C A L   F U N C T I O N S  *******************************************/

void set_hi_nibble(unsigned char data)		// output hi nibble data on port lines
{
	unsigned char temp=LATC;

	temp= temp & 0xF0;
	temp= temp | (data>>4);
	LATC=temp;
}

void set_lo_nibble(unsigned char data)		// output low nibble data on port lines
{
	unsigned char temp=LATC;

	temp= temp & 0xF0;
	temp= temp | (data & 0x0F);
	LATC=temp;
}

void en_set(void)			//function used to set Enable signal properly
{
	LATAbits.LATA6 = 1;		// Set EN on 1
	Delay1KTCYx(1);
	LATAbits.LATA6 = 0;		// Set EN on 0
}

void send_char(unsigned char c)
{
	LATAbits.LATA7=1;		// set RS on 1
	set_hi_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 50ms

	set_lo_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 5ms
}

void cmd(unsigned char c)
{
	LATAbits.LATA7=0;		// set RS on 0

	set_hi_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 50ms

	set_lo_nibble(c);
	en_set();
	Delay1KTCYx(5);			// delay 5ms
}

void InitUART(void)
{
	TXSTAbits.TX9=0;
	TXSTAbits.TXEN=1;
	TXSTAbits.SYNC=0;
	TXSTAbits.BRGH=1;
	TXSTAbits.TX9D=0;
	RCSTAbits.SPEN=1;
	BAUDCONbits.BRG16=0;
	SPBRG=25;				// 9600KBaud

	// receive config
	RCSTAbits.RX9=0;
	RCSTAbits.CREN=1;
	RCSTAbits.RX9D=0; 
}

void LCDInit(void)
{
 	Delay10KTCYx(20);		//Delay 200ms

	LATA=0;
	LATC=0;

	//Outputs
	TRISAbits.TRISA7=0;		//RS signal
	TRISAbits.TRISA6=0;		//EN signal
	
	TRISCbits.TRISC0=0;		// RC0 output, DB4
	TRISCbits.TRISC1=0;		// RC1 output, DB5
	TRISCbits.TRISC2=0;		// RC2 output, DB6
	TRISCbits.TRISC3=0;		// RC3 output, DB7
	TRISCbits.TRISC5=0;		// STATUS LED
	TRISCbits.TRISC6=0;		// UART_TX

	//Inputs
	TRISBbits.TRISB4=1;		//data0
	TRISBbits.TRISB3=1;		//data1
	TRISCbits.TRISC4=1;		// button
	TRISCbits.TRISC7=1;		//UART_RX
	
	// Oscillator frequency
	OSCCON=0b01100111;		// 4MHz

	// pins configurred as digital
	ADCON1=0b00001111;

	// Interrupt config
	INTCONbits.GIEH=1;       	// enables all high priority interrupts
	IPR1bits.RCIP=1;        	// EUSART Receive Interrupt High Priority
	RCONbits.IPEN=1;			// enable priority levels
	PIE1bits.RCIE=1;			// Enable EUSART receive interrupt

	LATAbits.LATA6=0;		// Set En on 0
	Delay1KTCYx(100);		//Delay 100ms
	
	LATAbits.LATA7=0;		// Set RS on 0
	Delay1KTCYx(15);		//Delay 15ms

	LATC=0x3;
	en_set();
	Delay1KTCYx(5);			// delay 5ms

	LATC=0x3;
	en_set();
	Delay100TCYx(1);		// delay 100us

	LATC=0x3;
	en_set();
	Delay10TCYx(4);			// delay 40us

	LATC=0x2;
	en_set();
	Delay10TCYx(4);			// delay 40us

	//Function set

	cmd(0x28);			// 4 bits, 2 lines, 5x7 dots format display mode
	Delay10TCYx(4);		// delay 40us

	//Display ON control

	cmd(0x0E);			// display on, cursor on, blinking cursor position off
	Delay10TCYx(4);		// delay 40us

	//Clear Display

	cmd(0x01);			// dispaly clear
	Delay1KTCYx(2);		// delay 2ms

	//Entry set increment

	cmd(0x06);			// increment, shift right
	Delay100TCYx(10);	// delay 1ms

}

void putch(unsigned char byte)
{
	while(!TXSTAbits.TRMT);
	TXREG=byte;
}

void send_dec_usart(void)		//convert binary number and display number in decimal 
{
	txarray[8]='\r';
	q=0;
	while(q<=8)
	{
		putch(txarray[q]);
		q++;
	}	
}

void lcd_goto(unsigned char data)						//set the location of the lcd cursor
{
 	if(data<16)											//if the given value is (0-15) the 
	{													//cursor will be at the upper line
	 	cmd(0x80+data);
	}
	else												//if the given value is (20-35) the 
	{													//cursor will be at the lower line
	 	data=data-20;									//location of the lcd cursor(2X16):
		cmd(0xC0+data);									// -----------------------------------------------------
	}													// | |00|01|02|03|04|05|06|07|08|09|10|11|12|13|14|15| |
}														// | |20|21|22|23|24|25|26|27|28|29|30|31|32|33|34|35| |
														// -----------------------------------------------------
void lcd_string(const char *s)
{
	while(*s)
		{
		//	Delay1KTCYx(10);	//Delay 10ms
			send_char(*s++);
		}
}

void writeString(const char *s)
{
	while(*s)
	{
		while(!TXSTAbits.TRMT);
		TXREG=*s;
		s++;
	}
}

/********************************************************************/
/*	 			Read the string from the USART interface			*/
/********************************************************************/
/*void interrupt(void)
{
	if(PIR1bits.RCIF)
	{
		if(RCSTAbits.FERR==1)
		{
			rxchar=RCREG;
			RCSTAbits.CREN=0;
			RCSTAbits.CREN=1;
		}

		if(RCSTAbits.OERR==1)
		{
			rxchar=RCREG;
			RCSTAbits.CREN=0;
			RCSTAbits.CREN=1;
		}

		rxchar=RCREG;
		TXREG=rxchar;

		if((rxchar!=0)||(rxchar!='\r'))
		{
			rxarray[r]=rxchar;
			r++;
		} 
					
		m=r-1;

		if((rxchar=='\r')||(rxchar==0)) // if the character is Enter flag is put on 1
		{
		//	flag=1;
			r=0;
			for(i=0; i<strlen(rxarray); i++) rxarray[i]=4;
			TXREG=12;
		}
	}
	PIR1bits.RCIF=0;
}*/
///////////////////functia main///////////////////////////////////////////

void main()
{
	//Initializations
	PORTC=0x00;
	LCDInit();
	InitUART();
	check=0;
	r=0;
	TXREG=12;
	col=0;
	row=1;
	flag=0;
//	cmd(0x01);

	while(1)
	{	
		if(PIR1bits.RCIF==1)
		{
			rxchar=ReadUSART();
			TXREG=rxchar;
			PIR1bits.RCIF=0;

			if(rxchar!='\r')
			{
			/*	if(col<16 && row==1)
				{
				 //	lcd_goto(0+col);
				}
				else
				{
					if(col>=16 && row==1)
					{ 
						col=0;
						row=2;
					//	lcd_goto(20+col);
					}
					else
					{
						if(col>=16 && row==2)
						{
							col=0;
							row=1;
							TXREG=12;
							cmd(0x01);			// clear display
							for(i=0; i<strlen(rxarray); i++) rxarray[i]='\0';  // vector initialization
						}
					}
				} */
			//	send_char(rxchar);
				rxarray[r]=rxchar;
				string[r]=rxarray[r];
				r++;
				col++;
				flag=0;
			}
			if(rxchar=='\r')
			{
				m=r-1;
				r=0;
				col=0;
				row=1;
				flag=1;
				for(i=0; i<strlen(rxarray); i++) rxarray[i]='\0';
				TXREG=12;
				cmd(0x01);
			}
			if(flag==1)
			{
				for(i=0; i<=m; i++)
				{
					col=i;

					if(col<16 && row==1)
					{
				 		lcd_goto(0+col);
					}

					if(col>=16 && row==1)
					{
						col=0;
						row=2;
						lcd_goto(20+col);
					}
											
					send_char(string[i]);
					Delay10KTCYx(3);
					col++;
				}
			}
		}
				
	}// while(1)
}//main
 

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  • wiegand_2620.zip
    3.8 KB · Views: 89

To me this does not look like LCD issue. When does the text gets corrupted ?

Code: 
if((rxchar!=0)||(rxchar!='\r'))
{
    rxarray[r]=rxchar;
    r++;
} 
					
m=r-1;

if((rxchar=='\r')||(rxchar==0)) // if the character is Enter flag is put on 1
{
//	flag=1;
	r=0;
	for(i=0; i<strlen(rxarray); i++) rxarray[i]=4;
		TXREG=12;
};

If you dont receive '\r' characters before you fill in the rxarray[], then you will get strange behavior ... You should handle that situation as well.
 
Last edited:

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