nýtt branch fyrir part3 og kóðar

include/pi_controller.h

@@ -0,0 +1,24 @@
+#ifndef PI_CONTROLLER_H
+#define PI_CONTROLLER_H
+
+class PI_controller
+{
+private:
+    double Kp;
+    double Ti;
+    double T;
+    double integral;
+
+public:
+    PI_controller(
+        double Kp,
+        double Ti,
+        double T
+    );
+
+    double update(double ref, double actual);
+
+    void reset();
+};
+
+#endif