Arduino: playing with LCD displays

My experimenting with the Arduino board is continuing even if I'm not gone so far from trying provided example sketches. That's why I'm writing so little about it. I recently got a couple of LCD display modules based on the Hitachi HD44780 chip, that is the most widely used character LCD standard.

Setting up the circuit

Connection the Arduino to a LCD display module is quite easy, four wires carry the data while two more (Enable and R/S) handle the control signals. Of course you can use the Arduino digital pins you prefer to carry the task but using pins 5,4,3 and 2 for data signals and pins 12 and 11 fro R/S and Enable pin respectively will let you test the provided examples without modification. Apart from connecting wires the only extra components needed are a couple of trimmers (small variable resistors) for LCD contrast and back-light intensity adjustment. Here how the whole circuit looks like (not different from what you can find on Arduino site examples.)