
179Chapter 7: Sensors
MOVEMENT AND ORIENTATION
People are active and mobile creatures. They
reach for things they want, turn toward loud
noises, and crouch down to coax the cat from
under the bed. When creating wearables that
react to events such as these, it is helpful to be
able to sense movement.
A cheap and easy way to sense movement is
through the use of tilt switches.
But there are also far more sophisticated
sensors you can use. Accelerometers measure
acceleration or changes in speed of movement.
They can also provide a good measurement of tilt
due to the changing relationship to gravity.
Accelerometers have a set number of axes—
directions ...