There is a medical monitoring service which monitors elderly inactivity with their sensors and their alarm sounds when sensors go inactive, but I don't remember their name, only seen the commercial 2 times. This could be costly. X10 also sells a pendent triggered box which has a autodialer to call up to 4 preprogrammed numbers for help, sounds from the person only input too, this is similar to their theft alarm box from what I remember.
BELOW is my idea X10's help but without ActiveHome which could be easier...
Call me crazy but here goes...
If you are a do it yourselfer, a 555 timer circuit, its timer circuit being reset to zero each time motion happens, then after a certain time of no activity the 555 timer reaches its set count and then an alarm could happen or other action. The interface wirelessly to the 555 circuit being tripped would be the hardest part. X10's motion sensors could be tied to the 555 circuits input through a 120v output from a module, stepped down to 5v or 1v DC based regulated voltage, small ac adapter probably best, unless you want to build a power supply, this needed on the logic input to the 555 TIMER IC and its output could drive a alarm through a relay or op amp circuit which if I remember correctly is in a 555 itself, or the other side used of a 556 dual timer IC. There are other ways to do this, other timer ICs, a resettable counter could be used from a digital 74 series IC itself too... Radio Shack did sell the 555 or 556 IC, and there are others such as Digi-Key, Jameco mail order companies.
I seem to be looking for something that does not exist and would appreciate any help anyone can offer to find a solution. I need to configure something like an occupancy sensor to activate an alarm if there is NO MOTION DETECTED for a period of time. It seems all of the devices I can find work by interrupting the power supply so will not send a signal to another device. I am looking for a way to either reverse engineer this to activate an additional connection instead of just closing as designed or a product that might operate on a timer that would automatically reset itself to the programmed time interval if it were not activated.
If I am over complicating something that already exists and I just have not located it yet, please tell me what I am looking for. But in searching the web for any application from security to medical alert devices I am not finding the solution. My application is small and I simply need to be notified if there is idleness in an area by any small or large means like no passage through a doorway or the absence of a door being opened or a space having any measurable movement.
Since there are so many products and devices that determine if there IS motion, there must surely be one that determines if there IS NOT motion. Help! lmendenhall Columbia, SC