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This research studied characteristics and sensing abilities of HC-SR04 ultrasonic sensor and applied internet of things to HC-SR04 ultrasonic sensor for physics experiment in coefficient of kinetic friction using knowledge of motion along a straight line with constant speeds and Stoke’s law to find the coefficients of kinetic friction between uPVC and borosilicate glass. The correlation between angular position of the obstacle object and displacement reading from HC-SR04 ultrasonic sensor was found in this research. Moreover, detections in percentages of HC-SR04 ultrasonic sensor were different in the displacement detections between the obstacle objects having their diameters larger/smaller than those of transmitter and receiver of HC-SR04 ultrasonic sensor. The coefficients of kinetic friction between uPVC and borosilicate glass were found in the range of 0.30-0.53. Furthermore, the correlation between speed of the obstacle object and kinetic friction force, and the correlation between normal force and coefficient of kinetic friction were found in this research. The displacement reading between the obstacle object and HC-SR04 ultrasonic sensor using HC-SR04 ultrasonic sensor-applied internet of things has more precision than that using manual devices consisting of a measuring tape and a stopwatch. The results provide similar accuracy between internet of things-applied HC-SR04 ultrasonic sensor and the manual devices in the case of applying the normal force of ³1.58 N.
 Kassim, A., Jaafar, H., Azam, M., Abas, N. and Yasuno, T., 2013, Performances studiedy of distance measurement sensor with different object materials and properties, pp. 281-284, IEEE 3rd International Conference on System Engineering and Technology.
 Awikunprasert, P., Wayopat, O., Wongke, T., Charnnuwong, T., Hanpanich, P. and Awikunprasert, C., 2017, Performance of infrared sensor and ultrasonic sensor for medical applications, SWU Sci. J. 33(1): 135-146. (in Thai)
 Noipon, A. and Maneerat, N., 2017, Metal classifying machine using ultrasonic testing method, Ladkrabang Eng. J. 34(2): 16-22. (in Thai)
 Hatthasin, U. and Payarach, N., 2015, Development of a sound system and detection safety tests in the obstacles-warning glasses for the visually impaired, pp. 553-558, The Eleventh National Conference on Computing and Information Technology. (in Thai)
 Chanprasert, K., 2017, Development of the obstacle warning instruments, Thai Sci. Technol. J. 25(1): 137-147. (in Thai)
 Wongke, T., Awikunprasert, P. and Awikunprasert, C., 2017, Digital height meter using ultrasonic sensor, J. Assoc. Med. Sci. 50(3): 435-441. (in Thai)
 Buachoom, A., Thedsakhulwong, A. and Wuttiprom, S., 2019, An Arduino board with ultrasonic sensor investigation of simple harmonic motion, J. Phys. Conf. Ser. 1380: 012098.
 Datasheetspdf, HC-SR04 User Guide, Available Source: https://datasheetspdf. com/pdf-file/1380138/ETC1/HC-SR04/1, April 27, 2020.
 Esploradores, Datasheet nodemcu, Available Source: https://www.esploradores.com/datasheet-nodemcu, April 27, 2020.
 Azwar, A.G., Laluma, R.H., Halim, R.P., Nurwathi, Gunawansyah and Gunawan, 2019, Smart trash monitoring system design using NodeMCU-based IoT, pp. 67-71, IEEE 13th International Conference on Telecommunication Systems, Services, and Applications.
 Atzori, L., Iera, A. and Morabito, G., 2010, The internet of things: A survey, Comput. Netw. 54: 2787-2805.
 Lu, T. and Neng, W., 2010, Future internet: The Internet of Things, pp. V5: 376-380, 3rd International Conference on Advanced Computer Theory and Engineering.
 Information and Communication Technology Center, Digital Skills to Digital Citizenship in 21st-Century, Available Source: https://www.ops.go.th/main/ index.php/knowledge-base/article-pr/1355-goto-citizens21st.html, April 23, 2020. (in Thai)
 Consumer Product Information Database, Material Safety Data Sheet – Sunlight, Available Source: https://whatsinproducts. com/files/brands_pdf/1366915304.pdf, April 23, 2020.
 Cytron Technologies, Product User’s Manual – HCSR04 Ultrasonic Sensor, Available Source: https://www.cytron. com.my, April 23, 2020.
 Lee, S., Choi, W. and Lee, D.H., 2019, Securing ultrasonic sensors against signal injection attacks based on a mathematical model, IEEE Access 7: 107716-107729.
 Tudor, D., Dobrescu, L. and Dobrescu, D., 2015, Ultrasonic electronic system for blind people navigation, pp. 1-4, E-Health and Bioengineering Conference.
 Deleau, F., Mazuyer, D. and Koenen, A., 2009, Sliding friction at elastomer/glass contact: Influence of the wetting conditions and instability analysis, Tribol. Int. 42: 149-159.
 Truncyte, D., Daukantiene, V. and Gutauskas, M., 2008, The influence of triboelectricity on textile polymer friction parameters, Fibres Text. East. Eur. 1(66): 50-53.