[SOLVED] interfacing two alpha numeric LCD with PIC controller

[mrarslanahmed]

hi

i working on pic 16f887 and using mikroc pro for programming, i am trying to interface two lcd with the controller, i have made function of each lcd for initialisation and data, when i use one data sending function at a time, system is ok, but when i use both data function , the system starts giving problem, content for one lcd are send to other lcd as well i have attached code below ,

// LCD module connections
sbit LCD_RS at RB3_bit;
sbit LCD_EN at RB2_bit;
sbit LCD_D4 at RB4_bit;
sbit LCD_D5 at RB5_bit;
sbit LCD_D6 at RB6_bit;
sbit LCD_D7 at RB7_bit;

sbit LCD_RS_Direction at TRISB3_bit;
sbit LCD_EN_Direction at TRISB2_bit;
sbit LCD_D4_Direction at TRISB4_bit;
sbit LCD_D5_Direction at TRISB5_bit;
sbit LCD_D6_Direction at TRISB6_bit;
sbit LCD_D7_Direction at TRISB7_bit;

// End LCD module connections


void init_main();
void Lcd2_init();
void LCD_break(unsigned int);
void lcd2_command(unsigned int);
void lcd2_data_string(char*);
void Break_data_lcd2(char);

void main()
{
     init_main();
     Lcd_Cmd(_LCD_CLEAR);
     LCD_OUT(1,1,"LCD1");
     lcd2_data_string("abcd");

}
void init_main()
{
     OSCCON=0x71;
     Delay_ms(50);

     TRISA=0;
     TRISB=0;
     TRISC=0;
     TRISD=0;
     TRISE=0;

     ANSEL  = 0;                                                                // Configure AN pins as digital I/O
     ANSELH = 0;
     C1ON_bit = 0;                                                              // Disable comparators
     C2ON_bit = 0;
     
     PORTA=0;
     PORTB=0;
     PORTC=0;
     PORTD=0;
     PORTE=0;

     Lcd2_init();
     lcd_init();
     Lcd_Cmd(_LCD_CLEAR);               // Clear display
     Lcd_Cmd(_LCD_CURSOR_OFF);          // Cursor off

}
void Lcd2_init()
{
     LCD_break(0x02);
     LCD_break(0x28);
                                                                                //LCD_break(0x08); // display off
     LCD_break(0x0F);                                                           // display on

     LCD_break(0x0C);
     LCD_break(0x06);                                                           
     LCD_break(0x80);
}
void LCD_break(unsigned int LCD_break)
{
     int temp_lcd_break;
     temp_lcd_break=(LCD_break & 0xF0);                                       // Mask lower nibble because RB4-RB7 pins are being used
     lcd2_command(temp_lcd_break);
     temp_lcd_break=((LCD_break<<4) & 0xF0);                                  // Mask lower nibble because RB4-RB7 pins are being used
     lcd2_command(temp_lcd_break);
}
void lcd2_command(unsigned int lcd_cmd)
{
     portc=lcd_cmd;
     portc.Rc3=0;                                                                // RS it is a command
     portc.RC2=1;                                                                // RS it is a command
     Delay_ms(10);
     portc.RC2=0;
     LCD_CMD=0;
}
void  lcd2_data_string(char* lcd2_string)
{
    int temp;
    for(temp=0;temp<=16;temp++)
    {
       if(!lcd2_string)
       break;
        Break_data_lcd2(lcd2_string[temp]);
        Delay_ms(25);
    }
    lcd2_string="";
}
void Break_data_lcd2(char data_lcd2)
{
     char temp_data_lcd2;
     temp_data_lcd2=(data_lcd2&0xF0);
     portc=temp_data_lcd2;
     portc.rc3=1;                                                               // register select 1 for data
     portc.rc2=1;                                                               // enable
     Delay_ms(10);
     portc.rc2=0;

     temp_data_lcd2=((data_lcd2<<4)&0xF0);
     portc=temp_data_lcd2;
     portc.rc3=1;                                                               // register select 1 for data
     portc.rc2=1;                                                               // register select 1 for data
     Delay_ms(10);
     portc.rc2=0;         
     temp_data_lcd2="";
}

i will be very pleased if some one can help me in this regard

 

[pic.programmer]

Use same pins of PIC to drive D4 to D7 of both LCDs. Also for RS pin but use seperate pins to drive EN pins of LCD.

 

[Easyrider83]

I think it is impossible to redefine pins with internal library. You will have to use your own library or make a logic switch externaly for 'E' pin for each lcd.

 

[zuisti]

Try this:
http://www.libstock.com/projects/view/959/full-lcd-library-set

Good luck: zuisti (Istvan K)

broken link removed

 

[pic.programmer]

Try attached project with mikroC PRO PIC.View attachment Dual LCDs 4 Bit.rar

Remember to uncheck the LCD and LCD_Constants in mikroC Library Manager.

 

[mrarslanahmed]

i really loved your approach.. i have never thought to use serial to parallel shift register in this way thus saving lot of money with some more coding using bit-banging concept..