Connecting a Lego motor
Over the years, Lego has released many motor designs for its various kits. Fortunately, they are all DC motors and easy to power with the bit:booster.
NXT and EV3 motors all use a cable that looks like an Ethernet cable but has an offset tab. This cable is has six wires of which we only need to use 2 to power a motor: the black and the white wires.
When Lego first released the NXT, they supplied transitional cables between Mindstorms components and NXT that look like the photo to the right. With this cable, you can directly connect the motor to the edge of the bit:booster. Otherwise, it is easiest to splice a cable to the outside connectors of a 3pin servo female jumper as shown in the image.
The Lego Power Functions and Lego Wedo (1.0) series motors have 4 wires in an integrated cable that has two Lego studs and one large oval with the power connectors. To power these motors, we only need to connect to the center 2. These can be spliced to the outside pins of a 3pin servo female jumper connector.
Rather than cut the cable from the motor, is is recommended that this splice is done to an extension cable so that the motor can still function with other Lego components.
NXT Robot with Jumper cables
Above is and example of a robot using the NXT motors with a jumper cable onto the motor control
Mindstorms/NXT Transition cable
Below is a close up of the Lego provided cables on controlling an EV3 motor clipped to the edge of the board.