Parallax X-Band Motion Detector
The Parallax X-Band Motion Detector is a relatively small lower power (8mA) radar motion detector. It is capable of detection up to slightly over 30 feet and is able to sense movement through windows and walls.
Something to keep in mind is that this is a radar detector so the speed of an object can be measured with it. However as stated in the user manual the area of detection is very wide unlike the focused radar beams of police speed detectors. So knowing this, measurements of speed will only be accurate if a single object is moving within the beam width of the detector. If more than one object is moving the measurement will not be a true measure of speed but instead could be interpreted as the "magnitude" of total movement.
Theory of Operation
This device quantifies the "magnitude" or speed of movement into pulses on the OUT pin. The pulses are more closely spaced together for faster movement and further apart for slower movement.
Parallax X-Band motion detector hooked up on a breadboard.
|X-Band Pins||mbed Pins|
|+5V||VU (5V )|
|EN||P26 (Or any Digital Out)|
|OUT||P25 (Or any Digital In)|
Demo Program Video
|xband (PinName pin_enable, PinName pin_inputA, PinName pin_inputB)|
Initialize the xband motion detector and setup interrupts on specified pins.
|void||enable (bool enable)|
Subroutine to enable and disable the detector.
Get count value and return it as an integer.
Resets the count variable to 0.
Checks if a new velocity value has been calculated.
Get current velocity reading.