Add object photogate to robot.java and add a todo comment to photogate subsystem.

[3501/stronghold-2016] / src / org / usfirst / frc / team3501 / robot / subsystems / Photogate.java

diff --git a/src/org/usfirst/frc/team3501/robot/subsystems/Photogate.java b/src/org/usfirst/frc/team3501/robot/subsystems/Photogate.java
new file mode 100644 (file)
index 0000000..33f7b15
--- /dev/null
+++ b/src/org/usfirst/frc/team3501/robot/subsystems/Photogate.java
@@ -0,0 +1,52 @@
+package org.usfirst.frc.team3501.robot.subsystems;
+
+import edu.wpi.first.wpilibj.AnalogInput;
+
+// TODO: Change certain reactions based on testing, ie what value(s) return true
+// and what value(s) return false.
+
+/***
+ * The photogate is a pair of IR LED and phototransistor sensor that uses a
+ * reflective method to sense the presence of the boulder within the robot's
+ * shooting chamber. This class specifically checks for the ball's presence
+ * using a threshold of voltages outputted from the phototransistor.
+ *
+ * @author niyatisriram
+ */
+public class Photogate extends AnalogInput {
+
+  private double threshold;
+
+  /***
+   * The constructor inputs the channel of the transistor and the threshold
+   * value.
+   * The threshold is a specific value, representing the outputted voltage of
+   * the phototransistor. This value will be somewhere within the range [0,
+   * 4095] Find the value by testing and finding an average value for which the
+   * ball is present when the output is greater, and absent when the output is
+   * less.
+   */
+  public Photogate(int channel, int threshold) {
+    super(channel);
+    this.threshold = threshold;
+  }
+
+  /***
+   * @return whether the ball is present or not
+   */
+  public boolean isBallPresent() {
+    if (this.getValue() > threshold)
+      return true;
+    else
+      return false;
+
+  }
+
+  /***
+   * @param threshold
+   *          (range [0, 4095]
+   */
+  public void setThreshold(int threshold) {
+    this.threshold = threshold;
+  }
+}