LCD Display Control

LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCD display is very basic module and is very commonly used in various devices and circuits. These modules are preferred over seven segments and other multi segment LEDs. The reasons being: LCDs are economical; easily programmable; have no limitation of displaying special & even custom characters (unlike in seven segments), animations and so on.

1. Initialize the Display

• Turn on Display by writing 1 to DB3
• Set display by writting 1 to DB2
• Turn on cursor by setting DB1 bit
• Turn on blinking cursor by writting to DB0

      DATA_PORT = 0b00001111;

2. Clear the display

• Set the DB0 bit to clear display

    DATA_PORT = 0b00000001;

3. Writing character to the display

• Set register select RS pin high
• Put the character in data port

    SETUP_PORT |= (1 << RS);
    DATA_PORT = character_ascii_value;

4. Writting a String

• Call lcd_write_char function looping through the string

    void lcd_write(char data[]) {
      int i;
      for(i=0; i<(strlen(data)); i++) {
          lcd_write_char(data[i]);
      }
    }

5. Writting any changes to display

• Set EN pin
• write values to RS or DATA_PORT
• wait for a while
• clear EN pin

Circuit Diagram

License

This work is licensed under GNU General Public License v3.0.