Make a graph plz help

[Whahahahaha]

@martijnroks

if (myPort.available() > 0) //als data beschikbaar is {
val = myPort.readStringUntil(‘\n’); // lees het uit en sla het op in val

what does it say when you put
println(val);
behind this?

that will print what processing gets from the arduino, perhaps something wrong happens there.