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1 | package org.usfirst.frc.team3501.robot.sensors; |
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2 | |
3 | import edu.wpi.first.wpilibj.AnalogInput; |
4 | |
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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 | |
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15 | private double threshold = 1.8; |
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16 | |
17 | /*** |
18 | * The constructor inputs the channel of the transistor and the threshold |
19 | * value. |
20 | * The threshold is a specific value, representing the outputted voltage of |
21 | * the phototransistor. This value will be somewhere within the range [0, |
22 | * 4095] Find the value by testing and finding an average value for which the |
23 | * ball is present when the output is greater, and absent when the output is |
24 | * less. |
25 | */ |
26 | public Photogate(int channel, int threshold) { |
27 | super(channel); |
28 | this.threshold = threshold; |
29 | } |
30 | |
31 | /*** |
32 | * @return whether the ball is present or not |
33 | */ |
34 | public boolean isBallPresent() { |
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35 | if (this.getVoltage() > threshold) |
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36 | return true; |
37 | else |
38 | return false; |
39 | |
40 | } |
41 | |
42 | /*** |
43 | * @param threshold |
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44 | * (range [0, 4095]) |
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45 | */ |
46 | public void setThreshold(int threshold) { |
47 | this.threshold = threshold; |
48 | } |
49 | } |