Continuing the discussion from Pre-release of Fibaro Motion Sensor:
The smartenIt 1019C is a zigbee multisensor with light, temperature, and motion. Good company, but the device is more limited than you may expect, read specs carefully. It’s certified for the zigbee Home Automation standard, so it may work with ST. Worth a try, although I don’t know if anyone’s written a device type that will work with it. It’s definitely designed for the basic use case you mention.