Since we will need to make things move in this project, we will be using a kind of motor. A motor is a device that converts electrical energy into mechanical energy, in other words, one that converts electricity into motion.

Various types of motors

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There are a vast number of motors out there... depending on the type of motion needed (linear or rotary), motor construction (brushed, brushless, stepper motor), type of current (AC or DC), and so on. Depending on what kind of motion we are looking for, which in turn depends on our application, we need to choose a motor that suits our requirements.

For our project, we will be using a Servo Motor, whose specialty is that it can move by specific amounts, or to a specific position, and even control its acceleration and velocity. Servo motors are traditionally used in RC cars and airplanes, but they can be used for all sorts of applications where precise control of position is required.

A servo motor

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If you took an ordinary motor, one that you typically find inside toys, you will find that they have two wires coming from them. If you apply voltage to it, the motor will begin to spin in one direction, and when you reverse the voltage direction by interchanging the wires, you will find that the direction also reverses.

In contrast, a Servo Motor has three wires: Power, Ground, and a third wire for command input. As mentioned earlier, a servo motor will move to a specific position, which would be specified through its command pin.

A servo is able to achieve this because of Feedback. There is a sensor coupled with the physical output of the motor that measures its position and velocity. The servo also has an internal controller that makes sure that the position and velocity of the output match the parameters taken as input from the command pin.

Internals of a servo motor

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Usually the hobby servos typically come with attachments for their shafts in the form of wheels or levers. These are called servo horns. These are useful when attaching the mechanisms that the servo will be driving to its shaft.

Servo Horns

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