180° Spatial Profiler and Obstacle Proximity Detection System Spatial Target Tracking and Real-Time Polar Radar Visualization Using an Ultrasonic Sensor, Servo Motor, Arduino, and NI LabVIEW

This report documents the design, implementation and replication procedure of the 180° Spatial Profiler, a low-cost mechanically scanned ultrasonic SONAR built for a Virtual Instrumentation course. An HC-SR04 ultrasonic ranger mounted on an SG90 servo is swept from 0° to 180° and back in 1° steps under the control of an Arduino Uno. At each step the firmware triggers the sensor, times the echo with pulseIn(), converts the pulse width to integer centimetres using 58.3 µs/cm, and sends an ASCII record “angle,distance” at 115200 baud over USB. A National Instruments LabVIEW virtual instrument reads the stream through VISA, converts the polar readings to Cartesian coordinates, and presents a polar radar display and a distance-versus-angle graph. The report gives the underlying theory, the complete verified firmware with a line-by-line explanation, a wiring and assembly guide, a reference LabVIEW implementation, validation protocols, a troubleshooting guide and the known limitations. The authors report that the assembled system works; however, no quantitative measurement dataset has yet been collected, so no accuracy, range or resolution is claimed. Analytical estimates, such as a 15° beam footprint of about 26 cm at 1 m and a nominal 10.86 s per 181-step pass, are labelled as such, and the results tables are provided blank.