DC motor speed control revisited
For the second example of using analog inputs, I have to use a very common electronic component in almost any project: a potentiometer, or simply, a variable resistor, which is a component that by the use of some kind of knob, allows us to change the resistance it offers.
Potentiometers are all around us, from the volume knob on your sound equipment to the temperature regulator of your heating system.
For this project, I'll combine a potentiometer with the motor speed controller we built in Chapter 4, Controlling Outputs Softly with Analog Outputs, in such a way that we can easily change the motor speed by acting on the potentiometer.
Two typical potentiometers along with their corresponding schematic ...