I am planning to build a robotic arm for a particular event in division C science Olympiad, but I am relatively unfamiliar with practical electronics (I know all the math, just not the hardware of it). The robot arm needs to pick up particular objects using a control that you make yourself. For the robot, I was planning to use 4 servo motors (rotation, grabbing, wrist, and elbow). However, I was considering a master-slave interaction to control the robotic arm, as I noticed that the top teams generally succeeded with this concept. Also, in my 'research', I noticed that for the master-slave concept, people used potentiometers for the control wired to an arduino microprocessor. What kind of potentiometers would I need, and how exactly do they work? Also, is there programming necessary to use these potentiometers to control the slave arm?