I am trying to make a little wireless-connected gizmo to attach to my grandfather's walking cane. The idea is that when it senses the cane has fallen down, it would alert/call one of us so that we can rush to him if we're not nearby.
The question is: What sensor or combination of sensors could I use to reliably differentiate between these two scenarios?
NORMAL situation: The cane is being held upright (or at only a slight angle from vertical) and used normally.
CRITICAL situation: The cane has been let go of, falls down and continues to lie on the floor/ground
Obviously, occasional false positives would be fine, but detection misses (false negatives) should be minimized.
I am thinking a combination of two things might help:
--sense whether my grandpa's hand is holding the cane or not (perhaps a light sensor that is blocked when the hand is on it?)
--sense whether the cane is upright or has taken a fall (perhaps an accelerometer+gyroscope+vibration sensor to determine orientation and shock events?)