LEGO MINDSTORMS Robots Manual page 136

Page 148
Attach the light sensor and wire bricks as shown. The light sensor goes on input 1,
while the two wire bricks (which will be attached to the touch sensors) go to
input 2 and input 3. If you get these two wires backwards, you'll know when you push the
joystick backward and the robot moves forward. You can easily swap the two
connectors later.