Test Lego motor

Test the motor to make sure each pin's function, as well as the connection of the wire.

Just connect pin 1 and 2 to a power supply(9V) and connect pin 3 to gnd, pin 4 to 4.3 V, pin 5&6 to oscilloscope. then the motor ran and the encoder feed back 2 signal, which was shown on oscilloscope. From the 2 signal we can calculate the speed of the motor 

The detail method wound not be introduced here, but it is a good question for students .