An insightful experimental procedure aimed to measure the gravitational acceleration is reported. The setup is made up of a simple pendulum apparatus, an ultrasonic position sensor, and an Arduino Uno board. The period of oscillations, which leads to the determination of the gravitational acceleration, is obtained from the time series plots of the position of the sensor associated to the pendulum crossing or clearing it periodically. The obtained value of the gravitational acceleration is 9.82 ± 0.10 m s −2 which is in a satisfactory agreement with our local theoretical value of 9.78 m s −2 . The percent error is 0.40%