This study aims to develop a device to investigate the moment constant of inertial rigid ball and rigid cylinder that rolls down an incline. The developed equipment consists of several components such as arduino, infrared sensor, Liquid Crystal Display (LCD), push button, actuator, and power supply. It is also equipped with a mechanical system. The equipment is controlled by the arduino. The developed electronic equipment serves to measure the time it takes for an object to roll on a slope. The result of the investigation shows that the change of track length does not affect the value of the inertial constant, whereas the change in the slope of the trajectory influences the value of inertial constants. The result of the investigation shows that the sphere’s constant inertia is 0.405 and cylinder’s constant inertia is 0.503 at the of 15° slope angle.

Keywords : Inertial Constants, Rolls, Arduino, Sensor.