added a command for zeroing the climber (#166)

* added a command for zeroing the climber

* "cleaned up angry stuff" hyrum

* voltage import begone

src/main/java/frc/robot/RobotPreferences.java

@@ -34,7 +34,8 @@ public static final class climberPref {
     public static final SN_DoublePreference climberMotorDownSpeed = new SN_DoublePreference(
         "climberMotorDownSpeed", -1);
     public static final SN_BooleanPreference climberInverted = new SN_BooleanPreference("climberInverted", false);
-
+    public static final SN_DoublePreference climberZeroingVoltage = new SN_DoublePreference("climberZeroingVoltage", 1);
+    // TODO: add value to a defualt to climberZeoringVoltage
     public static final SN_DoublePreference climberS = new SN_DoublePreference("climberS", 0);
     public static final SN_DoublePreference climberV = new SN_DoublePreference("climberV", 0.12);
     public static final SN_DoublePreference climberP = new SN_DoublePreference("climberP", 0.3);

src/main/java/frc/robot/commands/ZeroClimber.java

@@ -0,0 +1,59 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+package frc.robot.commands;
+
+import edu.wpi.first.wpilibj.Timer;
+import edu.wpi.first.wpilibj2.command.Command;
+import frc.robot.RobotPreferences.climberPref;
+import frc.robot.subsystems.Climber;
+
+public class ZeroClimber extends Command {
+  Climber subClimber;
+
+  double zeroingTimestamp;
+
+  /** Creates a new ZeroClimber. */
+  public ZeroClimber(Climber subClimber) {
+    this.subClimber = subClimber;
+
+    addRequirements(subClimber);
+  }
+
+  // Called when the command is initially scheduled.
+  @Override
+  public void initialize() {
+    subClimber.setClimberSoftwareLimits(true, false);
+
+    subClimber.setClimberVoltage(0);
+    zeroingTimestamp = 0;
+  }
+
+  // Called every time the scheduler runs while the command is scheduled.
+  @Override
+  public void execute() {
+    subClimber.setClimberVoltage(climberPref.climberZeroingVoltage.getValue());
+  }
+
+  // Called once the command ends or is interrupted.
+  @Override
+  public void end(boolean interrupted) {
+    subClimber.setClimberSoftwareLimits(true, true);
+  }
+
+  // Returns true when the command should end.
+  @Override
+  public boolean isFinished() {
+    if (Math.abs(subClimber.getClimberVelocity()) <= Math.abs(climberPref.climberZeroingVoltage.getValue())) {
+      if (zeroingTimestamp == 0) {
+        zeroingTimestamp = Timer.getFPGATimestamp();
+        return false;
+      }
+
+      return (Timer.getFPGATimestamp() - zeroingTimestamp) >= climberPref.climberZeroingVoltage.getValue();
+    }
+    zeroingTimestamp = 0;
+    return false;
+  }
+}