Index: firmware/App/Services/PIControllers.h
===================================================================
diff -u -r832ca83805dc132cb753e79bdca81197331e03e6 -rd830f37cf6a42a16399c87985bd51dfd9312ced3
--- firmware/App/Services/PIControllers.h	(.../PIControllers.h)	(revision 832ca83805dc132cb753e79bdca81197331e03e6)
+++ firmware/App/Services/PIControllers.h	(.../PIControllers.h)	(revision d830f37cf6a42a16399c87985bd51dfd9312ced3)
@@ -1,4 +1,4 @@
-/**************************************************************************
+/**********************************************************************//**
  *
  *  Copyright (c) 2019-2020 Diality Inc. - All Rights Reserved.
  *
@@ -19,26 +19,36 @@
 
 #include "Common.h"
 
+/**
+ *  @defgroup PIControllers PIControllers
+ *  @brief PIControllers service module.  Provides PI controllers for various actuators..
+ *
+ *  @addtogroup PIControllers
+ *  @{
+ */
+
 // ********** public definitions **********
 
+/// Enumeration of PI controllers
 typedef enum ControllerList
 {
-    PI_CONTROLLER_ID_LOAD_CELL = 0,
-    PI_CONTROLLER_ID_BLOOD_FLOW,
-    PI_CONTROLLER_ID_DIALYSATE_FLOW,
+    PI_CONTROLLER_ID_LOAD_CELL = 0,                 /// Load cell controller for dialysate outlet pump
+    PI_CONTROLLER_ID_BLOOD_FLOW,                    /// Flow controller for blood pump
+    PI_CONTROLLER_ID_DIALYSATE_FLOW,                /// Flow controller for dialysate inlet pump
     NUM_OF_PI_CONTROLLERS_IDS
 } PI_CONTROLLER_ID_T;
 
+/// Enumeration of PI controller signals
 typedef enum ControllerSignals
 {
-    CONTROLLER_SIGNAL_REFERENCE = 0,
-    CONTROLLER_SIGNAL_MEASURED,
-    CONTROLLER_SIGNAL_ERROR,
-    CONTROLLER_SIGNAL_ERROR_SUM,
-    CONTROLLER_SIGNAL_ERROR_SUM_AFTER_WINDUP,
-    CONTROLLER_SIGNAL_PROPORTIONAL_OUTPUT,
-    CONTROLLER_SIGNAL_INTEGRAL_OUTPUT,
-    CONTROLLER_SIGNAL_CONTROL,
+    CONTROLLER_SIGNAL_REFERENCE = 0,                /// Reference value
+    CONTROLLER_SIGNAL_MEASURED,                     /// Measured value
+    CONTROLLER_SIGNAL_ERROR,                        /// Error value
+    CONTROLLER_SIGNAL_ERROR_SUM,                    /// Error sum before anti-windup
+    CONTROLLER_SIGNAL_ERROR_SUM_AFTER_WINDUP,       /// Error sum after anti-windup
+    CONTROLLER_SIGNAL_PROPORTIONAL_OUTPUT,          /// P portion of controller output signal
+    CONTROLLER_SIGNAL_INTEGRAL_OUTPUT,              /// I portion of controller output signal
+    CONTROLLER_SIGNAL_CONTROL,                      /// Controller output signal
     NUM_OF_CONTROLLER_SIGNAL
 } PI_CONTROLLER_SIGNALS_ID;
 
@@ -50,5 +60,7 @@
 F32 runPIController( PI_CONTROLLER_ID_T controllerID, F32 referenceSignal, F32 measuredSignal );
 F32 getPIControllerSignals( PI_CONTROLLER_ID_T controllerID, PI_CONTROLLER_SIGNALS_ID signalID );
 
+/**@}*/
+
 #endif