Not getting data visible on LCD 16X2 when interfaced with MSP430G2553

Hi,

still it is not working,not viewind any data on screen.

I changed my code by adding delay(pls have a look over delay) kindly look my code.

I am using JHD 162A  LCD.

#include<msp430g2553.h>
#define RS    BIT0
#define RW    BIT1
#define EN    BIT2
#define line1 lcd_command(0x80)
#define line2 lcd_command(0xc0)

void lcd_command(unsigned char cmnd)
{

	P2OUT &= ~(RS);
	P2OUT &= ~(RW);
	P1OUT = cmnd;
	P2OUT |= (EN);
	_delay_cycles(1);                  //1us
	P2OUT &= ~(EN);
	_delay_cycles(100);               //100us
}

void lcd_data(unsigned char data)
{

	P2OUT |= (RS);
	P2OUT &= ~(RW);
	P1OUT = data;
	P2OUT |= (EN);
	_delay_cycles(1);      										    //1us
	P2OUT &= ~(EN);
	__delay_cycles(100);											//100us
	return;
}

void lcd_string(char *str)
{
	unsigned char i=0;
	while(str[i]!=0)
	{
		lcd_data(str[i]);
		i++;
	}
}


void lcd_init(void)
{
	P1DIR |= 0xFF;
	P2DIR |= 0xFF;

	P2OUT &= ~(EN);
	__delay_cycles(15000);                                   //15ms
	lcd_command(0x38);                                       //function set
	lcd_command(0x0E);                                       //display on cursor blinking
	lcd_command(0x01);										 //clear display screen
	lcd_command(0x02);										 // return home
	__delay_cycles(2000);									//2ms
	lcd_command(0x06);                                      //increment cursor
}

void main(void)
{
	WDTCTL = WDTHOLD + WDTPW;								//stop WDT
	lcd_init();

	line1;
	__delay_cycles(100);
	lcd_string("vikas");
	//__delay_cycles(100);                                  // 100us

	line2;
	__delay_cycles(100);
	lcd_string("Embin");
	//__delay_cycles(100);								   //100us

	while(1);

}

Vikas,

You will need to refer to the JHD 16A datasheet and ensure that you are following the connection and write mode diagrams exactly as instructed. A logic analyzer or oscilloscope would also help for looking at your communication lines. Can you get the commands to work, like get a blinking cursor on the second line? This will determine if the issue is isolated to the data write function.

Regards,
Ryan

hi,

will the issue of logic levels of LCD and MSP430G2553 gonna occur???

>will the issue of logic levels of LCD and MSP430G2553 gonna occur???

You don't specify how you are powering the MSP430, nor how you have everything wired. Necessary information to answer that question, otherwise we would just be guessing.

According to one datasheet that I found, Vih-min is 2.2 Volts, so the MSP outputs need to be higher voltage than that (Voh-min spec) to be compatible (on writing).

Have you tried single stepping your program in the debugger and checking the LCD connections to make sure the pins are toggling as you expect them?

Vikas,

please have a second look into the datasheet of the HD44780 controller. Your initialization is not according to the datasheet - it says that function set has to be sent three times with different delays in between. I have seen a lot of source codes from different people where the timing was not correct. Not sure if this solves your problem, but it could be an issue.

Dennis

Hi Vikas

Can you share the code which is working for JHD 162A LCD display ?

#include <msp430g2553.h>

#define DR          P2OUT = P2OUT | BIT0        // define RS high
#define CWR         P2OUT = P2OUT & (~BIT0) // define RS low
#define READ        P2OUT = P2OUT | BIT1    // define Read signal R/W = 1 for reading
#define WRITE       P2OUT = P2OUT & (~BIT1)     // define Write signal R/W = 0 for writing
#define ENABLE_HIGH P2OUT = P2OUT | BIT2        // define Enable high signal
#define ENABLE_LOW  P2OUT = P2OUT & (~BIT2)     // define Enable Low signal

void delay(unsigned int k)
{
	unsigned int i;
	unsigned int j;
    for(j=0;j<=k;j++)
    {
        for(i=0;i<100;i++);

    }

}
void data_write(void)
{
    ENABLE_HIGH;
    __delay_cycles(1);
    ENABLE_LOW;
}

void data_read(void)
{
    ENABLE_LOW;
    __delay_cycles(5);             //1msec
    ENABLE_HIGH;
}
/*
void check_busy(void)//busy flag will remain high(BF=1) until the initialization ends
{
    P1DIR &= ~(BIT7); // make P1.7 as input//reading input from the LCD//The busy state lasts for 10 ms after VCC rises to 4.5 V.
    while((P1IN&BIT7)==1)
    {
        data_read();
    }
    P1DIR |= BIT7;  // make P1.7 as output
}*/

void check_busy(void)
{
	         unsigned char i,j;
	         for(i=0;i<50;i++)        //A simple for loop for delay
	            for(j=0;j<255;j++);
}

void send_command(unsigned char cmd)
{
	P1OUT = (cmd);
	CWR;
	WRITE;
	data_write();
	check_busy();
}

void send_data(unsigned char data)
{
	P1OUT = (data);
	DR;
	WRITE;
	data_write();
	check_busy();
}

void send_string(char *s)
{
    while(*s)
    {
        send_data(*s);
        s++;
    }
}

void lcd_init(void)
{

    P2DIR = 0xFF;
    P1DIR = 0xFF;
    P2OUT = 0x00;
    P1OUT = 0x00;


    __delay_cycles(25000);										//delay for 25msec is perfect
    send_command(0x38);												//  3C 0F 06 01 80   works fine
    send_command(0x0E);										//set display on ,cursor off,blink on off
    send_command(0x06);										// set entry mode	//0x04 reverse string
    send_command(0x1C);										// right shift
    send_command(0x01);										//  clear the screen
    //send_command(0x80);										//Set Display Buffer RAM address

}


void main(void)
{
	WDTCTL = WDTPW + WDTHOLD; // stop watchdog timer
	lcd_init();


	send_command(0x86);
	__delay_cycles(5);													//5msec
	send_string("VIKAS");

	delay(5);
	send_command(0xC0);
	__delay_cycles(5);
	send_string("HURGAT");
	while(1){}


}