Beyond NXT Motors

Abstract

The NXT has three output ports with variable power and polarity control that you can use to activate a variety of devices above and beyond the NXT motors. The sophisticated pulse width modulation circuitry behind these ports was already described in Chapter 3. The NXT output power is on the same two wires that we used for passive sensors: the black and the white wires in the NXT cable, or pin 1 and pin 2 on the output port connector. The white wire will be positive and the black negative when the motor output is set to forward. For most of the projects that follow, we’ll only show only 18 gauge (0.8mm²) speaker wires, and you can presume they are attached to these two NXT connections.