It's not a real flash pattern used by police.
Just a few loops programmed by me to demonstrate some possibilities.
DISCLAIMER:
I AM NOT RESPONSIBLE FOR THE ACTIONS OR CONSEQUENCES REGARDING THIS TUTORIAL.
Use it only indoors and in private property!
It is not permitted to impersonate a police officer!
Find out how to get the scanner rgb leds in my other instructable.
Also possible with normal rgb leds. (I used common anode rgb leds)
I used the same type of scanner leds (from HP printer) as in my other instructable,
so the pinout is still: green, red, blue, common anode (from top to bottem)
If you use other leds, the order can be different!
Resistors:
I don't know the exact specifications of this led,
so I used resistor values slightly higher than probably necessary.
red: 200 Ohm
blue: 150 Ohm
green not used
I used a Arduino Nano here, but it will work equally well with the other Arduino types.