DFRobot's 24GHz mmWave Radar Offers Simple Person Detection — Even If They're Sleeping
This 24GHz FMCW and CW radar sensor can pick up people and animals at a range of up to 30 feet — even if they're staying still.
DFRobot has launched a "human presence detector" sensor, based on millimeter-wave (mmWave) radar — and capable of finding people even if they're standing still.
"In working, the sensor first emits FMCW [Frequency-Modulated Continuous-Wave] and CW [Continuous-Wave] radio waves to the sensing area," DFRobot explains of the device's operation. "Next, the radio waves, reflected by all targets which are in moving, micro-moving, or extremely weak moving state in the area, are converted into electrical signals by the millimeter-wave MMIC [Monolithic Microwave Integrated Circuit] circuit in the sensor system. After that, these signals will be sent to the processor and processed through the related signal and data algorithms. Then, the target information can be solved out.
"The millimeter-wave radar can sense the human presence, stationary and moving people within the detection area. Moreover, it can even detect static or stationary human presence such as a sleeping person. There are two ways provided to output detection result: Serial port and I/O port switch quantity. Besides that, the sensor module features strong sensing reliability, high sensitivity, small size, easy to be used or embedded in applications."
Drawing just 90mA in use, the 24GHz radar module offers a detection distance of 9m (around 30 feet) at a 100x40 degree beam angle. Designed for use with microcontrollers, the module is claimed to offer "strong anti-interference ability" with DFRobot claiming it can operate through snow, haze, dust, and in temperatures ranging from -40 to 85°C (around -40 to 185°F).
The sensor module is now available on DFRobot's website at $29, with a wiki entry showing its modes of operation and providing a sample Arduino sketch for person and animal detection.