To simulate the player striking the gangsa with a stick, a motor is required to copy the movement. There are different types of motors which could be used to automate this movement such as a stepper, DC and servo motor. Servo motors seemingly have the best attributes for this role with the ability to control the exact position of the motor along 180 degree angles of movement meaning it can be programmed to swing from a resting position(0 degrees) to a striking position(180 degrees). Servo motors are also easy to use with arduino boards which I am planning to interface between the sensor and the motor with.
