Faroqi, Adam, Adi Fitriadi, Neni Utami Adiningsih, and Muhammad Ali Ramdhani. 2018. “Automatic Door Control System Using SMS Gateway Base on Arduino Uno and Ultrasonic Sensor”. International Journal of Engineering & Technology 7 (3.4): 122-26. https://doi.org/10.14419/ijet.v7i3.4.16759.