challenge-bot.com Git - 3501/stronghold-2016/blob - src/org/usfirst/frc/team3501/robot/subsystems/DriveTrain.java

   1 package org.usfirst.frc.team3501.robot.subsystems;
   2
   3 import org.usfirst.frc.team3501.robot.Constants;
   4
   5 import edu.wpi.first.wpilibj.CANTalon;
   6 import edu.wpi.first.wpilibj.CANTalon.TalonControlMode;
   7 import edu.wpi.first.wpilibj.CounterBase.EncodingType;
   8 import edu.wpi.first.wpilibj.Encoder;
   9 import edu.wpi.first.wpilibj.PIDController;
  10 import edu.wpi.first.wpilibj.command.Subsystem;
  11
  12 public class DriveTrain extends Subsystem {
  13   // Drivetrain related objects
  14   private Encoder leftEncoder, rightEncoder;
  15   private CANTalon frontLeft, frontRight, rearLeft, rearRight;
  16   private PIDController frontLeftC, frontRightC, rearLeftC, rearRightC;
  17   // Drivetrain specific constants that relate to the inches per pulse value for
  18   // the encoders
  19   private final static double WHEEL_DIAMETER = 6.0; // in inches
  20   private final static double PULSES_PER_ROTATION = 256; // in pulses
  21   private final static double OUTPUT_SPROCKET_DIAMETER = 2.0; // in inches
  22   private final static double WHEEL_SPROCKET_DIAMETER = 3.5; // in inches
  23   public final static double INCHES_PER_PULSE = (((Math.PI)
  24       * OUTPUT_SPROCKET_DIAMETER / PULSES_PER_ROTATION) / WHEEL_SPROCKET_DIAMETER)
  25       * WHEEL_DIAMETER;
  26   // Drivetrain specific constants that relate to the PID controllers
  27   private final static double Kp = 1.0, Ki = 0.0, Kd = 0.0;
  28
  29   public DriveTrain() {
  30     frontLeft = new CANTalon(Constants.DriveTrain.FRONT_LEFT);
  31     frontRight = new CANTalon(Constants.DriveTrain.FRONT_RIGHT);
  32     rearLeft = new CANTalon(Constants.DriveTrain.REAR_LEFT);
  33     rearRight = new CANTalon(Constants.DriveTrain.REAR_RIGHT);
  34     this.configureTalons();
  35
  36     frontLeftC = new PIDController(Kp, Ki, Kd, frontLeft, frontLeft);
  37     frontRightC = new PIDController(Kp, Ki, Kd, frontRight, frontRight);
  38     rearLeftC = new PIDController(Kp, Ki, Kd, frontLeft, rearLeft);
  39     rearRightC = new PIDController(Kp, Ki, Kd, frontRight, rearRight);
  40     this.enablePIDControllers();
  41
  42     leftEncoder = new Encoder(Constants.DriveTrain.ENCODER_LEFT_A,
  43         Constants.DriveTrain.ENCODER_LEFT_B, false, EncodingType.k4X);
  44     rightEncoder = new Encoder(Constants.DriveTrain.ENCODER_RIGHT_A,
  45         Constants.DriveTrain.ENCODER_RIGHT_B, false, EncodingType.k4X);
  46     leftEncoder.setDistancePerPulse(INCHES_PER_PULSE);
  47     rightEncoder.setDistancePerPulse(INCHES_PER_PULSE);
  48   }
  49
  50   @Override
  51   protected void initDefaultCommand() {
  52   }
  53
  54   public void configureTalons() {
  55     frontLeft.changeControlMode(TalonControlMode.Speed);
  56     frontRight.changeControlMode(TalonControlMode.Speed);
  57     rearLeft.changeControlMode(TalonControlMode.Speed);
  58     rearRight.changeControlMode(TalonControlMode.Speed);
  59
  60     frontLeft.configEncoderCodesPerRev(256);
  61     frontRight.configEncoderCodesPerRev(256);
  62     rearLeft.configEncoderCodesPerRev(256);
  63     rearRight.configEncoderCodesPerRev(256);
  64
  65     frontLeft.enableControl();
  66     frontRight.enableControl();
  67     rearLeft.enableControl();
  68     rearRight.enableControl();
  69   }
  70
  71   public void enablePIDControllers() {
  72     frontLeftC.enable();
  73     frontRightC.enable();
  74     rearLeftC.enable();
  75     rearRightC.enable();
  76   }
  77
  78   public void drive(double left, double right) {
  79     frontLeftC.setSetpoint(left);
  80     rearLeftC.setSetpoint(left);
  81     frontRightC.setSetpoint(right);
  82     rearRightC.setSetpoint(right);
  83   }
  84
  85   public void resetEncoders() {
  86     leftEncoder.reset();
  87     rightEncoder.reset();
  88   }
  89
  90   public double getRightSpeed() {
  91     return rightEncoder.getRate(); // in inches per second
  92   }
  93
  94   public double getLeftSpeed() {
  95     return leftEncoder.getRate(); // in inches per second
  96   }
  97
  98   public double getSpeed() {
  99     return (getLeftSpeed() + getRightSpeed()) / 2.0; // in inches per second
 100   }
 101
 102   public double getRightDistance() {
 103     return rightEncoder.getDistance(); // in inches
 104   }
 105
 106   public double getLeftDistance() {
 107     return leftEncoder.getDistance(); // in inches
 108   }
 109
 110   public double getDistance() {
 111     return (getRightDistance() + getLeftDistance()) / 2.0; // in inches
 112   }
 113
 114   public void stop() {
 115     setMotorSpeeds(0, 0);
 116   }
 117
 118   public void setMotorSpeeds(double leftSpeed, double rightSpeed) {
 119     // speed passed to right motor is negative because right motor rotates in
 120     // opposite direction
 121     this.frontLeft.set(leftSpeed);
 122     this.frontRight.set(-rightSpeed);
 123     this.rearLeft.set(leftSpeed);
 124     this.rearRight.set(-rightSpeed);
 125   }
 126 }