Kari,

1. (((. I don't know what goes wrong, maybe timings or my circuit, but instead of having just "Hello world" once, it writes many times and the display is full of grab.)))

In my previous mail, I forgot to point to another important fact.
The LCD display has also an internal controller (a four bit generally) witch needs also some tine to recover from power down. It has an internal reset circuit with a defined time constant.
To see where the problem is I advice you to use a nonprofessional (but god) approach:
Put in your program a long delay ( 1..2 s ) routine immediately after the reset before the initialization of the internal SFRs. It is for debugging purpose only.
Therefore, the external hardware will have enough time to stabilize.
After you fix the problem, you may remove the delay.


Cristian