I have a 16 x 2 HD44780 LCD, and have it wired in the following way: LCD pin | Connected to 1 | Earth 2 | +5V 3 | Earth 4 | Parallel Port pin 16 5 | Earth 6 | Parallel Port pin 1 7 | Parallel Port pin 2 8 | Parallel Port pin 3 9 | Parallel Port pin 4 10 | Parallel Port pin 5 11 | Parallel Port pin 6 12 | Parallel Port pin 7 13 | Parallel Port pin 8 14 | Parallel Port pin 9 15 | +5V 16 | Earth The problem I am having is that I cannot get it to work, I have tried LCD Smartie, but it doesnt seem to do anything, I have tried restarting PC etc, but the LCD just stays with all its squares solid. Anyone have any ideas what I could be doing/have done wrong?
pin 3 you connected it directly to ground. you must connect it to a pot so you can vary the voltage thus adjusting the LCD contrast. its working fine but your not seeing anything due to the contrast problem. take a look at this circuit diagram on this site http://www.linuxfocus.org/English/September2002/article258.shtml
OK, so I connect VSS to Earth and one side of the pot, VLC to the middle of the pot, 5V to VDD and the other side of the pot?
true. you should see be able to adjust contrast now, try moving the pot you will notice the black rectangles start to disapear and text will apear.
