HD44780 LCD

Hi there,

First of all I want to clarify that I am not English. I am from Germany. So please be indulgent to me.

I orderd a week ago this LCD: http://www.amazon.de/HD44780-Module-Display-Anzeigen-Zeichen/dp/B009GEPZRE/ref=sr_1_2?ie=UTF8&qid=1380735596&sr=8-2&keywords=arduino+lcd

Today it was delivered and of course I wanted to build some test projects to learn about the display. In the internet I already found this circuit:

But my Arduino Leonardo R3 has no VV3 Port. How I am supposed to connect the LCD to the Arduino?

Thanks for your help. 8) faxe

I don't understand the problem. All the connections you need seem to be there on the Leonardo. VV3?

Sorry I wanted to say that the LCD has no "connection" named VCC (the red cable).

Well what connections does it have, faxe?

Does the maker not provide a datasheet?

Different manufacturers label the +5V pin with different letters. If your display is actually the same as the one that is pictured in your link then the +5V connection is made to pin 2.

You will probably have to connect the backlight (pins 15 and 16) in order to see anything on your display. You may need a series current limiting resistor.

When you get it working I think you will find that the row of pins is in the upper left of the display not in the lower right as shown in the picture.


Vcc just means positive supply voltage. In the case of your LCD, this means connect it to +5V.

Vcc is shorthand for "supply voltage to the transistor collectors" and generally assumes NPN transistors which have a positive collector supply.

Similarly, "Vee" refers to the emitters, usually of NPN transistors, which is a negative supply and usually ground. Some logic families however (ECL) used a supply negative to ground which was Vee. And certain depletion-mode FET families characteristically used a positive ground. The terms "Vdd" and "Vss" are sometimes used to refer to drain and source supplies for FETs.