1) The LM317 can be replaced by any other 3,5V positive voltage regulator.

2) If the LCD has got only one controller, PD5 can be left unconnected.

3) If the LCD has got no backlight, PD3 can be left unconnected.

4) The backlight has to be powered by a seperate power supply, connected to Vbl.

5) R1 needs to be chosen according to Vbl and the requirements of the backlight.