Printing Serial Data from Arduino into a Processing IDE GUI

Hi @Handrup, Welcome to the forum. There’s basically two steps to what you want, and many options to each step, nearly infinite variations (and a good few ways of it going wrong). I made an example which should work straight away. You could use it as a starting point, or at least to give you ideas.

Next time please say what works/doesn’t, maybe copy from serial monitor of what Arduino is printing.