I am trying to find a way to send a signal to a key fob type of equipment. I have a pressure sensitive matt and need to send a signal to a key fob when there is pressure on the matt and no movement for a determined amount of time. Does anyone know how to accomplish this?
"Wireless door-bell" springs to mind as the data communications method. Some come with battery receivers that aren't much larger than a key fob and can be re-engineered to be much smaller, if the endurance required allows for a smaller battery.
Pressure sensitive mats come in switched output form - so easy enough to wire across the bell push button contacts. If they are the changing resistance type, a simple comparator will do the job.
Movement detection is a bit trickier. You could use a PIR sensor that provides an output signal that is used as the source for the mat. Thus the PIR would have to be detecting movement *and* the pressure mat would have to detect pressure, in order for the input to the transmitter to become active.