Arjun vuppaladadium week3

build.gradle

@@ -1,6 +1,6 @@
 plugins {
     id "java"
-    id "edu.wpi.first.GradleRIO" version "2025.2.1"
+    id "edu.wpi.first.GradleRIO" version "2025.3.2"
     id 'com.diffplug.spotless' version '6.20.0'
 }
 

src/main/java/frc/robot/subsystems/ArmSubsystem2.java

@@ -0,0 +1,53 @@
+// Homework for Week 2
+package frc.robot.subsystems;
+
+import com.ctre.phoenix6.configs.Slot0Configs;
+import com.ctre.phoenix6.controls.PositionVoltage;
+import com.ctre.phoenix6.hardware.TalonFX;
+import edu.wpi.first.wpilibj2.command.SubsystemBase;
+
+public class ArmSubsystem2 extends SubsystemBase {
+
+  private static final double kRotationsPerRadian = 10.0; // 5 rotations (0.5 radians) * 2
+
+  private final TalonFX motor;
+  private double targetPos;
+  private final PositionVoltage positionRequest;
+
+  public ArmSubsystem2() {
+    motor = new TalonFX(1);
+
+    Slot0Configs slot0 = new Slot0Configs();
+    slot0.kP = 2.0;
+    slot0.kI = 0.0;
+    slot0.kD = 0.1;
+    motor.getConfigurator().apply(slot0);
+
+    positionRequest = new PositionVoltage(0).withSlot(0);
+  }
+
+  public void setPos(double rad) {
+    targetPos = rad;
+    motor.setControl(positionRequest.withPosition(rad * kRotationsPerRadian));
+  }
+
+  public double getPos() {
+    return motor.getRotorPosition().getValueAsDouble() / kRotationsPerRadian;
+  }
+
+  public void zeroEncoder() {
+    motor.setPosition(0.0);
+  }
+
+  public boolean isAtTargetPos(double tolRad) {
+    return Math.abs(getPos() - targetPos) <= tolRad;
+  }
+
+  public void stop() {
+    setPos(getPos());
+  }
+
+  public double getTargetPos() {
+    return targetPos;
+  }
+}

src/main/java/frc/robot/subsystems/Week3_Notes.txt

@@ -0,0 +1,31 @@
+Command Scheduler:
+Runs commands ever 20 ms
+Contains a scheduler that registers the buttons pressed/commands needing to be ran, and runs them accordingly
+Once a command is run, the scheduler ends the command
+Runs periodic() method in each Subsystem
+
+Subsystems:
+Abstraction for a collection of robot hardware that operates as one
+Most methods private so methods can be replicated safely in other Subsystems
+CommandScheduler never schedules a command that comes from the same subsystem--either interrupts current command or is ignored
+Default commands-automatically scheduled when no other command is running
+Take care of basic functionality
+
+Creating Subsystems:
+extends SubsystemBase, holds common methods that are useful for each subsystem
+one variable for each piece for hardware
+motors and sensors defined at top--private and final
+initialize hardware in constructor
+if you need to access values, use getters & setters
+
+Periodic method:
+Called every 20 ms
+usually logs/getters for values
+updates basic values/basic tasks
+dont control motors
+
+Requirements and default commands:
+Only one method per subsystem at any given time
+periodic always runs, so if method that moves motors is ran and the robot is in a bad circumstance, it is bad
+since motor commmands cant be called in periodic, they are called in "Default Command"
+default command--gaurantees behavior if input