Last year, I took a look at some mostly low-cost passive infrared (PIR) motion sensor modules. Then recently, I became more aware of cheap microwave radar motion sensor modules. The popular version of ...

Detection using today’s microwave sensors has some advantages. Unlike traditional passive infrared motion sensors, most microwave sensors can distinguish between moving and static objects, and objects ...

Your garden variety motion detector uses IR, but these days, there are fancier technologies for achieving similar goals. If so desired, you can source yourself a microwave-based presence sensor ...

Many close-proximity motion detectors use the classic, widely available passive-infrared (PIR) approach, which is effective but has limited sensitivity and adjustability, and can’t “see” through ...

Marrian Zhou is a Beijing-born Californian living in New York City. She joined CNET as a staff reporter upon graduation from Columbia Journalism School. When Marrian is not reporting, she is probably ...