This ultrasonic radar project is from [mircemk] who uses a small ultrasonic distance sensor attached to a rotating platform. A motor rotates it around a 180-degree field-of-view and an Arduino ...

Arduino is able to interpret signals from a variety of sensors. By placing a unit equipped with an ADXL345, an accelerometer for detecting motion, or a Piezo sensor on a door, it can notify you when ...

If you want to play with radar — and who could blame you — you can pretty easily get your hands on something like the automotive radar sensors used for collision avoidance and lane detection.