diff --git a/CPP_Implementation/apid_controller.cpp b/CPP_Implementation/apid_controller.cpp
index a61ecb8..e520e79 100644
--- a/CPP_Implementation/apid_controller.cpp
+++ b/CPP_Implementation/apid_controller.cpp
@@ -1,10 +1,17 @@
 #include "apid_controller.h"
 
+/**
+ * @brief Constructor to initialize PID gains and time step.
+ */
 aPIDController::aPIDController(double kp, double ki, double kd, double dt)
     : Kp(kp), Ki(ki), Kd(kd), dt(dt), integral(0.0), prev_err(0.0) {}
 
+/**
+ * @brief Update the PID output based on the target and measured value.
+ */
 double aPIDController::update(double target, double measured_value) {
-    double error = target - measured_value;
+    double error = target - measured_value; 
+
     integral += error * dt;
     double derivative = (error - prev_err) / dt;
     prev_err = error;