Please correct this LCD code

[Naumanpak]

Hi experts,

I have had a great experience with edaboard, you people have helped me a lot.

I have this LCD code for 16x4 module. But the problem is that every time I run it, i only get black boxes on row 1 and 3. Any suggestions??


thanks

#include <regx51.h>


#define rs       P2_5
#define rw       P2_6
#define enable   P2_7
#define lcd_port P0
#define XTAL     11.059200  
#define XDIVIDER 12.0       

#define delay_1ms 164 * (XTAL/XDIVIDER)

void delay(unsigned char);
void delay_ms(unsigned int);
void lcd_display(unsigned char);
void Lcd_Ini();
void lcd_command(unsigned char);
main()
{
                unsigned int i;
		lcd_command(0x01);
		Lcd_Ini();
                lcd_command(0x80);
                lcd_display('L');
                lcd_display('I');
                lcd_display('N');
		lcd_display('E');
		lcd_display('1');
                lcd_command(0xC0);
                lcd_display('L');
                lcd_display('I');
                lcd_display('N');
		lcd_display('E');
		lcd_display('2');
		lcd_command(0x94);
                lcd_display('L');
                lcd_display('I');
                lcd_display('N');
		lcd_display('E');
		lcd_display('3');
	        lcd_command(0xd4);
                lcd_display('L');
                lcd_display('I');
                lcd_display('N');
		lcd_display('E');
		lcd_display('4');

				while(1){;}     
}
   
void Lcd_Ini()
{
                lcd_command(0x48);
                delay_ms(30);
                lcd_command(0x0c);
                delay_ms(10);
                lcd_command(0x06);
                delay_ms(10);
                lcd_command(0x01);                    
                delay_ms(10);
}
  
void lcd_command(unsigned char command)
{
                rw=0;
                rs=0;
                lcd_port=command;
                enable=1;
                enable=0;
                delay_ms(5);
}
  
void lcd_display(unsigned char display)
{
                rw=0;
                rs=1;
                lcd_port=display;
				enable=1;
                enable=0;
                delay_ms(1);
}

void delay_ms(unsigned int i)
{
 
       			for(;i!=0x00;i--)
               			{
               			delay(delay_1ms);
                        }
}

void delay(unsigned char j)
{
                for (;j!=0x00;j--)
                        {
                        }
}

 

[daviddlc]

Some LCDs need software initialization when the hardware initialization does not work.

If you don't initialize correct, they will do weird things.

Google for LCD software initialization and give it a try.

Also insert a NOP between RW and RS setting, this depends on the speed of the system. So try:

RW = 0;
NOP();
RS=0;
NOP();

this is to let the signal to settle.

 

[dksoba]

Can you post a picture of what's happening? Do your rows start on row 0, or row 1?

If our rows are laid out as:

Row1
Row2
Row3
Row4

Usually row3 is an extension of row1. There for to type:

edaboard.com is a friendly place to get advice.

It would look like this

Row1: edaboard.com is
Row2:
Row3: a friendly place t
Row4:

Matt

 

[Naumanpak]

thanks Matt & daviddlc for suggestions. I have tried NOP(); but same problem yet.

this is what I get on LCD

 

[nandhu015]

This is initialisation problem. You have to initialize the lcd before sending data

Nandhu

 

[Naumanpak]

Thanks Nandhu, I did the initialization with Lcd_Ini(); right at the top in main()

Can you please tell me exactly what to do now..?


cheers

 

[himrwt]

put in some delay between initialization codes

 

[daviddlc]

In my previous post, I asked you to Google for LCD software initialization, you will see some examples there.

Added after 5 minutes:

This is what I have for a 2 x 16, you will need to adapt to your needs:

void LCD_InitDisplay()
{
RS = 0; //RS = 0
RW = 0; //R/W = 0
Delay10KTCYx(36); //Wait aprox. 30 mSec.
PORTB = 0x30; //Function Set: 8 bits
Delay10KTCYx(6); //Wait aprox. 5 mSec.
PORTB = 0x30; //Function Set: 8 bits
Delay1KTCYx(2); //Wait aprox 100uSec. (166 uSec)
LCD_WriteCommand(0x38); //Function Set: 8 bits, 2 lines, 5x7 character font
LCD_WriteCommand(0x0C); //ON/OFF Control: Display on,
LCD_WriteCommand(0x01); //Clear display
LCD_WriteCommand(0x06); //Increment, no shift
}//LCD_InitDisplay

Again remember the NOP() after RS and RW settings depends on the system speed.

 

[DNS28]

I have made a C18 library to use my LCD. It is not optimized but it works with no problems. Hope it helps.

/*
Biblioteca para usar LCD com PIC18F4431
Autor: Diego Sá
Data: 07/03/2010
*/

//--Evitar que este header file seja incluído várias vezes no programa
#ifndef __LCD_CONFIG_H //Verifica se a expressão __LCD_CONFIG_H ainda não foi definida
#define __LCD_CONFIG_H //Define a expressão __LCD_CONFIG_H
//--

#define RS PORTBbits.RB2
#define RW PORTBbits.RB3
#define EN PORTBbits.RB4
#define DATA PORTD
#define TRIS_DATA TRISD
#define NEW_LINE 0x0A
#define BUSY_FLAG PORTDbits.RD7

void configLCD(void);
void SendCmdLCD(unsigned char cmd_lcd);
void WriteCharLCD(char e);
void WriteTextLCD(char *text);
void BusyFlagCheck(void);

char j=0;
char d;

void configLCD(void)
{
	TRISBbits.TRISB2=0;  //Pino RS como output
	TRISBbits.TRISB3=0;  //Pino RW como output
	TRISBbits.TRISB4=0;  //Pino EN como output

	EN=0;
	RS=0;
	RW=0;

	BusyFlagCheck();
	
	SendCmdLCD(0b00111000);//Function Set: 8-bit bus mode; 2-line display mode; 5X8 dots format display
	Delay1KTCYx(10); //Delay 5ms
	SendCmdLCD(0b00001111);//Display Control: Display ON; Cursor ON; Cursor blink ON
	Delay1KTCYx(10); //Delay 5ms
	SendCmdLCD(0b00000001);//Clear Display
	Delay1KTCYx(10); //Delay 5ms
	SendCmdLCD(0b00000110);//cursor moves to right; DDRAM adress increased by 1; disply shifting is not performed
}

void SendCmdLCD(unsigned char cmd_lcd)
{
	TRIS_DATA=0b00000000;
	EN=0;
	RW=0;
	RS=0;
	
	DATA=cmd_lcd;

	Delay10TCYx(2); //Aguarda 20 ciclos (10 uSeg)

	EN=1;

	Delay1KTCYx(10);// Aguarda 5ms
			// Ciclos = (TimeDelay * Fosc) / 4
			// Ciclos = (5ms * 8MHz) / 4
			// Ciclos = 10,000
	EN=0;

	Delay10TCYx(2); //Aguarda 20 ciclos (10 uSeg)

	DATA=0b00000000;

	Delay10TCYx(2); //Aguarda 20 ciclos (10 uSeg)

	BusyFlagCheck();
}

void WriteCharLCD(char e)
{
	TRIS_DATA=0b00000000;

	EN=0;
	RW=0;
	RS=0;

	Delay10TCYx(2); //Aguarda 20 ciclos (10 uSeg)

	RS=1;
	DATA=e;

	Delay10TCYx(2); //Aguarda 20 ciclos (10 uSeg)

	EN=1;

	Delay1KTCYx(10);// Aguarda 5ms

	EN=0;

	Delay10TCYx(2); //Aguarda 20 ciclos (10 uSeg)

	DATA=0b00000000;
	RS=0;

	Delay10TCYx(2); //Aguarda 20 ciclos (10 uSeg)

	BusyFlagCheck();
}

void WriteTextLCD(char *text)
{
	j=0;

	while(*text)
	{
		d=*text++;

		if (d==NEW_LINE)
		{
			break;
		}
		else
		{
			WriteCharLCD(d);
			j++;
			if (j>16) break;
		}
	}
}

void BusyFlagCheck(void)
{
	TRIS_DATA=0b11111111;
	
	EN=0;
	RS=0;
	RW=1;
	Delay1KTCYx(10); //Delay 5ms
	
	while (1)
	{
		EN=1;
		Delay10TCYx(1);

		if (BUSY_FLAG==0)
		{
			break;
		}
		else
		{
			EN=0;
			Delay1KTCYx(10); //Delay 5ms
		}
	}

	EN=0;
	RW=0;
	TRIS_DATA=0b00000000;
}

#endif

 

[Naumanpak]

O thank you all! another solution within 24hrs!

I finally got it working with a bit of more delays and setting rs and rw to 0 in initialization.

thank you all once again!!

Added after 3 minutes:

I have another problem but I will post it as an another topic.