Ok, I’m back and I have the solution in my bag.
This display actually works very well with the standard Arduino LCD library. No need to download the above mentioned additional 4bit library.
It is true though that you have to use this display in 4-bit mode.
Here is how:
Hook everything up EXACTLY like in this picture from the Arduino page:
Now load the “Scroll” Example from Arduinos LiquidCrystal Library.
Change these two lines
lcd.begin(16, 2);
lcd.setCursor(0,7);
to
lcd.begin(8, 2);
lcd.setCursor(0,0);
now upload it to your Arduino or Seeduino and watch your display fire up!
You may have to adjust the potentiometer a little if you can’t see anything.
As an alternative to the potentiometer you can connect the Vo pin of the LCD with any available PWM-output (I use pin 9) and add the following code in the setup() section:
pinMode(9, OUTPUT);
analogWrite(9, CONTRAST);
replace CONTRAST with the value of your choice. Values around 10-20 give a nice bright output.
@ESP:
please add this information to the depot-page of the display and update the picture shown there because pin1 and pin2 have to be swapped and pin3 must not be connected to GND or you have a contrast of 0.