* (64[steps] * 4[duration]) / 64[PWM periods/s] = 4 second breath cycle
*
* http://www.wolframalpha.com/input/?i=%28sin%28+x%2F64*pi%29**8+*+255%2C+x%3D0+to+63
* (64[steps] * 4[duration]) / 64[PWM periods/s] = 4 second breath cycle
*
* http://www.wolframalpha.com/input/?i=%28sin%28+x%2F64*pi%29**8+*+255%2C+x%3D0+to+63