ALAT UKUR TINGGI BADAN ELEKTRONIK MENGGUNAKAN SENSOR ULTRASONIC DAN ANDROID SMART PHONE DENGAN KONEKSI BLUETOOTH

Abstract

Height measuring tool is a tool that is widely used in the community, especially in hospitals, police agencies and several other places that need it. Most height measuring tools are manual, so reading the measurement results still takes a little time, because you have to carefully look at the scale of the measuring instrument. This paper discusses the results of research on making a prototype of a height measuring instrument automatically electronically which is displayed on an LCD screen and can be monitored via an android smart phone. This measuring instrument consists of hardware in the form of an electronic circuit with the main components of the Arduino nano microcontroller, proximity sensor and LCD display. The proximity sensor uses an ultrasonic sensor module HC-05 which has specifications that can measure a maximum distance of ± 3 m. This sensor is used to measure a person's height. The concept of measuring height using an ultrasonic sensor is by emitting ultrasonic waves with a frequency of 40 Khz and if the wave hits an object, the ultrasonic wave is reflected back. The ultrasonic wave reflection can be calculated mathematically so as to produce a measuring distance from the object with the ultrasonic sensor position. Besides being displayed on the LCD, the measurement results are also displayed on the Android smart phone screen via a Bluetooth connection. After the test, the average error was about 0.29 when compared to manual measurements, because the surface of the head is not flat so that the reflected ultrasonic waves are always changing.