Penentuan Frekuensi Alamiah Benda Berosilasi Menggunakan Mikrokontroler AT89C51

An experiment has been carried out to demonstrate the detection of natural frequency of an oscillating object. A potentiometer is as sensor to detect the position change of the oscillating object and to produce analog data. An analog-digital converter (ADC) 0804 converts these data to digital data and then recorded by a microcontroller AT89C51 automatically. The output of microcontroller is connected to computer equipped software interface with Delphi 5.0. The data are recorded in worksheet excel and plotted a graphic, damped oscillation amplitude as a function of time. As its application to detect natural frequency, some oscillating objects had been recorded, for an object 65 cm long has natural frequency ( ?b) of 3.91795 ± 0.00127 rad/second, an object 75 cm long has natural frequency ( ?b) of 3.62072 ± 0.03056 rad/second and an object 85 cm long has natural frequency ( ?b) of 3.42578 ± 0.00248 rad/second. The longer object and bigger oscillation angle, the natural frequency reduce