Hi @Myrdalm, In your Processing sketch you are connecting to ‘Serial.List()[0]’ Are you sure that’s the BT com port? What’s in that list is going to change when you add/remove the Arduino. I think it’s more reliable to put the name of the port there hard coded as e.g. “COM4”. I hope you’re looking at the available ports in device manager to check what each one is.
If the BT software/hardware on the PC is not working well, please see the comments here about using a USB-TTL-HC05 as an alternative.
In your Arduino code, I don’t think you should have pinMode settings on the SoftwareSerial pins. That’s not done in the given example.
Please edit your first post, select the Processing code and press control-e. This will format it nicely and make it easier for anyone to copy and test. Repeat for Ard code.
