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 ...

The microcontroller-based concept was chosen because I wanted to scale the sensor system later to suit other applications. Here is the diagram of my Arduino infrared close proximity sensor. As you can ...

[mircemk] shows how to create a simple non-contact proximity sensor using little more than an Arduino Nano board, and a convenient software library intended to measure the value of capacitors.

The physics of the situation makes it possible to measure either distance or velocity from either type of electromagnetic wave—there are lidar speed sensors and radar range finders. But in ...