Finaly I got the 8x2 LCD working.
I had some problems first, but I solved it.
The contrast adjustment should be tied to "near ground" 0.3v - 0.0v, or else you wouldn't see anything...
The test loop simply puts an "x" to the display, clears the screen and the write an "x" again. Well, now I know that the LCD is working, and I can start doing some more serious programing. Like puting the barometric preassure in hPa and height above sea level on the screen :-)
That means some sort of clever conversion from 16bit value to a string of characters.