On May 12, 6:16 pm, PinkFloyd43 wrote:
Create a circuit with bright red LEDs that would attached
to the front and back of a motorcycle helmet that would
flash for x period of time when the operator moved their
head left to right, like saying NO, NO to a car about
ready to pull out in front on you....

Red is a wrong choice - a color harder to detect. Automobiles
designed by engineers (not by fashion designers) use orange (amber)
rear turn signals. Orange cuts through fog, smoke, rain, etc; and is
easier to see at dawn and dusk.

Sources of motion sensors include those $1 electronic pedometers or
game handles from Wii video games.