Processing to Arduino serial

I am trying to send arduino serial commands.
I have set up port4 after following some documentation in the sample files.
the below code is not working as expected, textfield11 has a float value inside and the arduino command i need through serial would be “y200.3” as an example.
any help greatly appreciated

<
public void button1_click1(GButton source, GEvent event) { //CODE:button1:461790:
transf = (textfield11.getText());
transf = “y” + transf;
println(transf);
myPort.write(transf);
} //CODE:button1:461790:
/>

Hi @danjy,

Have you tried this tutorial to successfully send data between the Processing IDE and the Arduino IDE and vice-versa?

https://learn.sparkfun.com/tutorials/connecting-arduino-to-processing/all

Best regards

Hi @danjy, are you making progress? I made an example that will almost certainly work first time. Then you could replace the test data with yours.