The Motion Detector is designed with two detecting sensors, Passive Infra-Red (PIR) sensor and light sensor, to detect movement within a protected area. The detector can be used as a security device or home automation device. When the detector is cooperated with security appliances, the detector is acting as a security device by detecting changes in infra-red radiation levels. If a person moves within or across the devices field of vision, a trigger radio signal will be transmitted to cause full alarm condition in order to frighten intruders away. Alternatively, when the detector is worked with Z-Wave Controller , the detector can be set to perform the role of home automation device by detecting both changes in infra-red radiation levels and percentage of lux levels. Once night falls, the percentage of ambient illumination is lower than preset value. If a person moves within or across the devices field of vision, a trigger radio signal will be transmitted so as to turn connected lightings for better illumination.