LCD Tutorial 7

Tutorial 7 - Marquee part 2      

This project proves to be more challenging than tutorial 7. Instead of using command_shift, I simply rely on the display address in order to move the letter across the LCD module from right to left. Each letter starts at 0x90 which cannot be seen on the LCD panel (See more information  in tutorial 3). 

Each letter moves backward until it reaches on the 1st character on the 1st line. The second letter will stop at 2nd character of the LCD module, third letter stop at third character. It keeps going until the letter run out. The codes has been hardly changed apart from the character_mode prototype function as it needs to be modified in order to operate as marquee.

// Prototype function 

void character_mode(tByte *s)
{
        tByte string,ADDRESS=0X90;
        tWord x,P;
// Switch character mode on 
// RS=ON
        P=16;

        while(*s != 0x0)
        {

                string=*s;

                for (x=0; x<=P; ++x)
                {
                RS=ON;
                table_lookup(string);
                pulse_e();
                RS=OFF; 
                RS=ON;
                DATA=0x20;
                pulse_e();
                RS=OFF;

                --ADDRESS;
                display_address(ADDRESS);
                Delay_Loop(5);
            }
                        s++;
                        ADDRESS=0x90;
                        display_address(ADDRESS);

                        --P;

        }

}

Download Tutorial 7 Code

LCD Tutorial 6

Tutorial 6 - Marquee part 1      

Another function prototype such as command_shift has specifically added in this tutorial. This prototype function is designed to shift the character either left or right. According to the command set table, the fifth row indicates that 0x18 and 0x17 would be used for shifting left and right respectively.

In the character mode prototype function has been slightly modified as the global variable such as size_G is used to count the maximum character in text. Then the size_G add with the local variable such n=16 because of the number characters in the LCD module. 

Basically the code below just shift the text across the LCD module from right to left. In the 'do' section includes the delay_loop which allow the text stay on the LCD module for few seconds then shift again. When the text disappear from the screen, the 0x01 is executed in order to clear the display screen and repeat the above process again. 

// Global Variable
int size_G;

void main(void)
{
        int n;

        // Configure LCD module into 2 lines, 8-Bits and 5x7 Pixels
        function_set();
        // Blinking and underline cursor
        display_cursor(0x08);

        while(1)
        {
        // Place character on $00
        display_address(0x80);
        // Enter characters
        character_mode("TEST");
        // Determine the max length of characters
        n=16+size_G;
        // Blinking and underline cursor
        display_cursor(0x0c);

        do
        {
        Delay_Loop(20);
        // Shifting text from right to left
        command_shift(0x18);
        n--;
        }       while(n !=0x00);
        // Clear display
        DATA=0x01;
        pulse_e();
        } 

}

Download Tutorial 6 Code