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interfacing lcd 8 bit mode with pic 16f877a

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madogas

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hi for all i have problem with my lcd it is not display the function only display _ and i dont know the problem plz help me
tis is the code for my prog it is about controlling applications by gsm sms
Code:
// include
//==========================================================================
#include <pic.h>
#include <string.h>
#include<htc.h>
// configuration
//==========================================================================
__CONFIG ( 0x3F32 ); //configuration for the microcontroller

// define
//==========================================================================
#define rs RD4 //RS pin of the LCD display
#define e RD5 //E pin of the LCD display
#define lcd_data PORTB //LCD 8-bit data PORT
#define LED1 RD6
#define LED2 RD7
#define LED3 RC4
#define SW1 RA3


// function prototype (every function must have a 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); //receive uart value
void uart_send(unsigned char data);
void uart_str(const char *s);

void gsm_send_command(const char *command);
void gsm_read_line(char *buffer);


// global variable
//==========================================================================

char gsm_response[20];
char command[10];


// main function (main fucntion of the program)
//==========================================================================
void main()
{
char read_sms_command[] = "AT+CMGR=1";
char delete_sms_command[] = "AT+CMGD=1";


//set I/O input output
TRISB = 0; //configure PORTB I/O direction
TRISD = 0b00000000; //configure PORTD I/O direction
TRISA = 0b00000111; //configure PORTA I/O direction
TRISC = 0b00001111; //configure PORTC I/O direction
LED1=0; // OFF LED1
LED2=0; // OFF LED2
LED3=1;
//Configure UART
SPBRG=9600; //set baud rate as 115200 baud
BRGH=1; //baud rate high speed option
TXEN=1; //enable transmission
TX9 =0; //8-bit transmission
RX9 =0; //8-bit reception
CREN=1; //enable reception
SPEN=1; //enable serial port

//setup ADC
ADCON1 = 0b00000110; //set ADx pin digital I/O

//configure lcd
send_config(0x00000001); //clear display at lcd
send_config(0x00000010); //lcd return to home
send_config(0x00000110); //entry mode-cursor increase 1
send_config(0x00001100); //display on, cursor off and cursor blink off
send_config(0x00111000); //function set

//display startup message
lcd_clr(); //clear lcd
send_string("Cytron Tech."); //display "Cytron Tech."
lcd_goto(20); //set the lcd cursor to location 20
send_string("Smart Home"); //display "Smart Home"

// Delay for a while.
delay(100000);



// Clear the LCD and display the new message.
lcd_clr();
send_string("Testing Com...");

// Make sure we can communicate with the GSM modem.
gsm_send_command("AT");

// Read the response.
gsm_read_line(&gsm_response);

// We should receive "OK" from the GSM modem.
// If we don't, display "Error".
if (memcmp("OK", &gsm_response, 2) != 0)
{
lcd_clr();
send_string("Error...");
while(1);
}



// Clear the LCD and display the new message.
lcd_clr();
send_string("Waiting for");
lcd_goto(20);
send_string("Call Ready");

// Waiting for the GSM modem to search for the network.
// We will receive a blank line before receiving "Call Ready".
gsm_read_line(&gsm_response);
gsm_read_line(&gsm_response);

// We should receive "Call Ready" from the GSM modem.
// If we don't, display "Error".
if (memcmp("Call Ready", &gsm_response, 10) != 0)
{
lcd_clr();
send_string("Error...");
while(1);
}



// Clear the LCD and display the new message.
lcd_clr();
send_string("Setting Text");
lcd_goto(20);
send_string("Mode...");

// Set text mode for SMS.
gsm_send_command("AT+CMGF=1");

// Read the "OK".
gsm_read_line(&gsm_response);



// Clear the LCD and display the new message.
lcd_clr();
send_string("Ready");



while(1)
{
// Check whether there is new data from the GSM modem.
if (RCIF == 1)
{
// Check is there a new SMS?
gsm_read_line(&gsm_response);
if (memcmp("+CMTI: \"SM\",", &gsm_response, 12) == 0)
{
// Get the SMS index.
// The command array is already initialized as "AT+CMGR=1" and "AT+CMGD=1",
// we need to changed the index to the actual one.
read_sms_command[8] = gsm_response[12];
delete_sms_command[8] = gsm_response[12];

// Clear the LCD and display the new message.
lcd_clr();
send_string("Reading SMS...");

// Send command to read the SMS.
gsm_send_command(&read_sms_command);

// Read the response.
// The first line is the SMS info which we don't need.
// We only need the second line which is the message content.
gsm_read_line(&gsm_response);
gsm_read_line(&command);

// Read the newline and "OK".
gsm_read_line(&gsm_response);
gsm_read_line(&gsm_response);



// Switch on the light if we received "on".
if (memcmp("on1", &command, 2) == 0)
{
LED1 = 1;
}
if (memcmp("on2", &command, 2) == 0)
{
LED1 = 2;
}
// Switch off the light if we received "off".
else if (memcmp("off1", &command, 3) == 0)
{
LED1 = 0;
}
else if (memcmp("off1", &command, 3) == 0)
{
LED2 = 0;
}


// Send command to delete the SMS.
gsm_send_command(&delete_sms_command);

// Read the "OK".
gsm_read_line(&gsm_response);



// Clear the LCD and display the new message.
lcd_clr();
send_string("Ready...");
}
}



// Check whether SW1 is pressed.
if (SW1 == 0)
{
// Clear the LCD and display the new message.
lcd_clr();
send_string("Sending SMS...");

// Send the SMS to notify the owner.
// Please change this to your own number.
gsm_send_command("AT+CMGS=\"0123456789\"");

// We should receive '>' from the modem.
// If we don't, display "Error".
if (uart_rec() != '>')
{
lcd_clr();
send_string("Error...");
while(1);
}

// Send the message.
uart_str("Warning: Switch 1 has been triggered !");

// Send <CTRL+Z>.
uart_send(0x1a);



// Read the newline and response.
gsm_read_line(&gsm_response);
gsm_read_line(&gsm_response);

// We should receive "+CMGS: <Message ID>" from the GSM modem.
// If we don't, display "Error".
if (memcmp("+CMGS:", &gsm_response, 6) != 0)
{
lcd_clr();
send_string("Error...");
while(1);
}



// Read the newline and "OK".
gsm_read_line(&gsm_response);
gsm_read_line(&gsm_response);



// Clear the LCD and display the new message.
lcd_clr();
send_string("Ready...");



// Wait until SW1 is released so that we don't send duplicated message.
while (SW1 == 0);

}
}
}

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

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
{
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++);
}


void gsm_send_command(const char *command)
{
unsigned char rec_data;

while (*command != 0)
{
uart_send(*command++); // Send the AT command.
rec_data = uart_rec(); // Read the echo.
}

// Send <ENTER>.
uart_str("\r\n");

// Read the echo until Line Feed character is received.
do {
rec_data = uart_rec();
} while (rec_data != '\n');
}



void gsm_read_line(char *buffer)
{
unsigned char rec_data;

// Read the data until Line Feed character is received.
do {
rec_data = uart_rec();
*buffer++ = rec_data;
} while (rec_data != '\n');
}
 

Check your hardware connection .have you made RW pin of LCD ground.
 

yes it is pin 5 in the lcd i connect it to ground
 

plz help me iam out of time
 

No answer an till now thanx alot
 

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