In Circuit 10, what is the purpose of the diode? Why is the diode parallel and not serial with the motor?
In Circuit 10, what is the purpose of the transistor? What happens to the current through the motor when the voltage on the transistor’s base pin is 5 volts? What happens to the current through the motor when the voltage on the transistor’s base pin is 0 volts?
Use the multimeter to measure the current through the motor when pin 9’s analog output is 0 and when it is 255.
Swap the two motor wires in Circuit 10, what happens?