Display problem with HD44780

[Hgetis]

Greetings to all!!

Yesterday I build my own parallel HD 44780 LCD display using this tutorial: http://www.electronics-lab.com/projects ... index.html.
Unfortunately my LCD although it seems to be refreshed for a "nanosecond", using LCD Smartie, digits' dots are black all the time.
If the characters are still, and no refresh needed then LCD keeps in black dots.

Trying to fix the problem I start searching LCD Smartie website and found that the connection I used was this:


when u propose this one (taken from here: http://lcdsmartie.sourceforge.net/circuits.htm):


Is there any problem with the connection diagramm I have used or maybe the solution to my problem is somewhere else?
As I see difference are on pin 14 of parallel port, which in my diagramm is not connected (plus on LCD's side is connected at +5V), and on pins 18-25 which in your wiring diagramma are Grounded, when in mine are not.

Thank you in advance..
Hgetis
A begginer from Greece...

[caesar]

You have to rewire it. Smartie uses the RW line that is connected to GND in your wiring method.
Also GND to LPT pins 18-25 is needed too.

[Hgetis]

Thank you for your answer!

In my diagramm (wiring) there are no resistors attached. Is there any problem about that?

It will be a painful procedure deassembling and rewiring...

[caesar]

No problem, leave LCD pins 1,2,3, 15, 16 as they are.

Resistor on LCD pin 16 is necessary only if your display doesn't have an internal resistor for backlight.
Resistor on LCD pin 3 is necessary only to tune the displays contrast but on most LCD's connecting it to GND is sufficient.

[IFR]

For some lcd like mine, having potentiometers attached for the contrast or backlight is a good idea as it affect the view angle.

[Hgetis]

thank you again!

that was helpful!