Problems with LCD showing random characters - Displays - Arduino Forum

Hi, I've just started using the Arduino and this is the first project I've done on my own so I'm having a lot of problems, but now I have one with the LCD screen that I can't fix: as I run the code the screen seems to work but then it starts showing random characters. Putting the code on an online simulator it seems to work so probably the problem is in the wiring or something but I don't know what it can be (I've read that there can be noise problems but I don't understand what I have to do).

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