challenge-bot.com Git - 3501/stronghold-2016/blob - src/org/usfirst/frc/team3501/robot/commands/intakearm/Photogate.java

   1 package org.usfirst.frc.team3501.robot.commands.intakearm;
   2
   3 import edu.wpi.first.wpilibj.AnalogInput;
   4
   5 /***
   6  * The photogate is a pair of IR LED and phototransistor sensor that uses a
   7  * reflective method to sense the presence of the boulder within the robot's
   8  * shooting chamber. This class specifically checks for the ball's presence
   9  * using a threshold of voltages outputted from the phototransistor.
  10  *
  11  * @author niyatisriram
  12  */
  13 public class Photogate extends AnalogInput {
  14
  15   private double threshold = 1.8;
  16   static boolean ballState;
  17
  18   /***
  19    * The constructor inputs the channel of the transistor and the threshold
  20    * value.
  21    * The threshold is a specific value, representing the outputted voltage of
  22    * the phototransistor. This value will be somewhere within the range [0,
  23    * 4095] Find the value by testing and finding an average value for which the
  24    * ball is present when the output is greater, and absent when the output is
  25    * less.
  26    */
  27   public Photogate() {
  28     super(0);
  29     this.threshold = threshold;
  30
  31   }
  32
  33   /***
  34    * @return whether the ball is present or not
  35    *         USE TO DECIDE WHEN OUTTAKE NEEDS TO HAPPEN FOR BALL TO BE SECURE
  36    */
  37   public boolean isBallPresent() {
  38     if (this.getVoltage() > threshold) {
  39       ballState = true;
  40       return true;
  41     } else
  42       ballState = false;
  43     return false;
  44
  45   }
  46
  47   public static boolean ballState() {
  48     return ballState;
  49   }
  50
  51   /***
  52    * @param threshold
  53    *          (range [0, 4095])
  54    */
  55   public void setThreshold(int threshold) {
  56     this.threshold = threshold;
  57   }
  58 }