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Text LCD Enhanced

Table of Contents

  1. New features
  2. Example Code
  3. Examples
  4. References

This page describes an enhanced forked version of the basic driver code library for Text LCD panels using the 4-bit HD44780 lcd display driver.

New features

  • Support for more LCD types
    • TextLCD::LCD8x1 8x1 LCD panel
    • TextLCD::LCD8x2 8x2 LCD panel
    • TextLCD::LCD16x4 16x4 LCD panel
    • TextLCD::LCD24x2 24x2 LCD panel
    • TextLCD::LCD24x4 24x4 LCD panel (for KS0078 controller)
    • TextLCD::LCD40x2 40x2 LCD panel
  • Support for Cursor and/or Blinking current character
  • Support for User Defined Characters to display special symbols
  • Improved methods to get and set the memory address of the current character

Example Code

// Hello World! for the TextLCD

#include "mbed.h"
#include "TextLCD.h"

// Host PC Communication channels
Serial pc(USBTX, USBRX); // tx, rx

//TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD16x4); // rs, e, d4-d7 ok
//TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD20x2); // rs, e, d4-d7 ok
TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD20x4); // rs, e, d4-d7 ok
//TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD24x2); // rs, e, d4-d7 ok
//TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD40x2); // rs, e, d4-d7 ok

int main() {
    pc.printf("LCD Test. Columns=%d, Rows=%d\n\r", lcd.columns(), lcd.rows());
    
    for (int row=0; row<lcd.rows(); row++) {
      int col=0;
      
      pc.printf("MemAddr(Col=%d, Row=%d)=0x%02X\n\r", col, row, lcd.getAddress(col, row));      
      lcd.putc('-');
//      lcd.putc('0' + row);
      
      for (col=1; col<lcd.columns()-1; col++) {    
        lcd.putc('*');
      }

      pc.printf("MemAddr(Col=%d, Row=%d)=0x%02X\n\r", col, row, lcd.getAddress(col, row));      
      lcd.putc('+');
        
    }       
}

Examples

Some results are shown here:

/media/uploads/wim/_scaled_img_2636.jpg

/media/uploads/wim/_scaled_img_2638.jpg

/media/uploads/wim/_scaled_img_2637.jpg

/media/uploads/wim/_scaled_img_2640.jpg

/media/uploads/wim/_scaled_img_2642.jpg

The terminal will print the actual memory address like this:

LCD Test. Columns=20, Rows=4

MemAddr(Col=0, Row=0)=0x00

MemAddr(Col=19, Row=0)=0x13

MemAddr(Col=0, Row=1)=0x40

MemAddr(Col=19, Row=1)=0x53

MemAddr(Col=0, Row=2)=0x14

MemAddr(Col=19, Row=2)=0x27

MemAddr(Col=0, Row=3)=0x54

MemAddr(Col=19, Row=3)=0x67

References

All wikipages