Evan you only have 2 sensor input ports on that Lego 9750 box I lost track what you have connected, you should make a diagram to further your documentation I remember one button is connected for the Drive Motor So the other button is connected for the Steering Motor ? Because then you don't have any Sensor Input ports left over, in order to connect a Limit switch on the Steering Motor to prevent damage So I wondered what you had in mind, Dan
Ports 0-5 are for motors and lights. Ports 6-7 are for sensors. I am using one port from the first bank to control the drive motor, another to control the V-8 motor (just for fun; it's not actually connected to the drivetrain, kids don't need to know that!), and a third port to control the steering motor. I used a sensor in the second bank to know when the steering rack (Lego rack-and-pinion steering!) is at its maximum mechanical limit. Joystick buttons and the associated paddle 0/1 have nothing to do with the interface box, that's plugged into the standard Apple game port.