An experiment has been conducted to investigate oscillation motion on simple pendulum system by using Hall effect sensor and arduino. The hardware for experiment used were push button, Hall effect sensor, arduino, LCD display, indicator lamp, and power supply. Meanwhile the software used were C code program by using IDE ardunio compiler. Mechanic device used were stative scaffolder, rope, magnetic ball, digital scales, and ruler. The experiment is aimed at investigating the effect of rope length, mass of object, and oscillation angle toward the period and frequency of oscillation as well as to measure acceleration of gravitation. The result showed that the acceleration of gravitation gained was 9.87 ± 0.06 m/s2 with percentage of error reached 0.71% if compared to the theoretic value. The result also showed that oscillation period was equal with the length root of rope, meanwhile oscillation frequency was equal with one per length root of rope. Besides that, the result also proof that mass of object and oscillation angle was not influential toward period and frequency of oscillation on simple pendulum system.