Work on adding advantagekit

src/main/java/frc4388/robot/subsystems/differential/PID.java

@@ -0,0 +1,29 @@
+package frc4388.robot.subsystems.differential;
+
+import frc4388.utility.structs.Gains;
+
+public class PID {
+    protected Gains  gains;
+    private   double output    = 0;
+
+
+    /** Creates a new PelvicInflammatoryDisease. */
+    public PID(Gains gains) {
+        this.gains = gains;
+    }
+
+    private double prevError, cumError = 0;
+    
+    // Called every time the scheduler runs while the command is scheduled.
+    public double update(double error) {
+        cumError += error * .02; // 20 ms
+        double delta = error - prevError;
+
+        output = error * gains.kP;
+        output += cumError * gains.kI;
+        output += delta * gains.kD;
+        output += gains.kF;
+
+        return output;
+    }
+}