|Problem: Develop a simple
way to help his waiters know when someone at a table needed service.
Solution: A flashing
light on the table would get the waiter's attention. The circuits for the battery powered device which when activated would flash some
lights is shown below.
The circuit consists of a single 3v lithium coin cell battery to power the device. Four super
bright green LEDs are flashed when the assembly was rotated into the “Requested Service”
position. A tilt switch senses when the device is in that position. A simple timer
turns off the flasher after 3 minutes, if left in the flashing position.