Subekti, S., Pranoto, H., Salmon, B.R., Yusuf, S.Q., Suyadiyanto, S., Ariyadi, A.S. and Hamid, A. 2020. Preventive maintenance of taper bearing using Arduino in the application of industry 4.0. International research journal of engineering, IT & scientific research. 6, 4 (Jul. 2020), 1–14. DOI:https://doi.org/10.21744/irjeis.v6n4.953.