The major component, in addition to Arduino board is the LED light bar. The LED Bar is a prepackaged strip of 3 high-output LEDs powered by 12VDC. Each unit comes with a fully assembled and tested PCB ...

That worked perfectly because I had 70. Tip: If you want to use a different number of lights, you can calculate the area available on your own sweater and place the lights as you see fit.

Let it hit your red LED and you’ve lost a point. But if you can push your button while your yellow LED is lit, the light speeds up tremendously until the next button press in the green.