In this example we connect an LCD to our mbed LPC1768 and display some text on it, we use a library to do most of the hard work here so our development is made easy by the TEXT LCD library.
The schematic shows how to connect up the 16×2 LCD to the mbed LPC1768
Schematic

Code
#include "mbed.h"
#include "TextLCD.h"
TextLCD lcd(p15, p16, p17, p18, p19, p20, TextLCD::LCD16x2); // rs, e, d4-d7
int main() {
lcd.printf("Hello World!\n");
}