Reference for Wiring version 1.0 Build 0100+ If you have a previous version, use the reference included with your software. If see any errors or have any comments, let us know.
|Description||HALF_PI is a mathematical constant with the value 1.57079632679489661923. It is half the ratio of the circumference of a circle to its diameter. It is useful in combination with the trigonometric functions sin() and cos().|