name="l00006"></a><span class="lineno">    6</span>&#160;<span class="comment">A class for reading voltage on a digital pin, derived from http://arduino.cc/en/Tutorial/RCtime.</span></div><div class="line"><a name="l00007"></a><span class="lineno">    7</span>&#160;<span class="comment">This is designed to be used in updateControl().  Each time it is called, it checks if a capacitor has charged,</span></div><div class="line"><a name="l00008"></a><span class="lineno">    8</span>&#160;<span class="comment">a