Arduino Mini Radar (Servo + HC-SR04 + OLED Display)

A movie-style radar from a distance sensor and a servo! The **SG90 servo** sweeps the **HC-SR04** from 0 to 180 degrees while the **0.96 inch OLED** draws a rotating sweep line and shows detected objects as dots. When something enters the range, the **passive buzzer** pings, and the pitch rises as the object gets closer. Servo control, ultrasonic measurement, trigonometry-based drawing and `tone()` sound in one project.