Index: firmware/App/Services/PIControllers.c
===================================================================
diff -u -rd830f37cf6a42a16399c87985bd51dfd9312ced3 -r55a6adaf81175d25c1d9cc4c96d7dfda84eede16
--- firmware/App/Services/PIControllers.c	(.../PIControllers.c)	(revision d830f37cf6a42a16399c87985bd51dfd9312ced3)
+++ firmware/App/Services/PIControllers.c	(.../PIControllers.c)	(revision 55a6adaf81175d25c1d9cc4c96d7dfda84eede16)
@@ -1,12 +1,12 @@
 /**********************************************************************//**
  *
- *  @file PIControllers.c
- *
  *  Copyright (c) 2019-2020 Diality Inc. - All Rights Reserved.
  *
  *  THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
  *  WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
  *
+ *  @file PIControllers.c
+ *
  *  @date 18-Dec-2019
  *  @author L. Baloa
  *
@@ -21,10 +21,17 @@
 #include "SystemCommMessages.h"
 #include "PIControllers.h"
 
+/**
+ *  @addtogroup PIControllers
+ *  @{
+ */
+
 // ********** private definitions **********
 
+/// minimum integral coefficient - cannot be zero
 #define MIN_KI                      NEARLY_ZERO
 
+/// record for PI controller
 typedef struct {
     // -- PI's parameters --
     F32 Kp;                         /// Proportional Value
@@ -38,7 +45,7 @@
     F32 errorSumBeforeWindUp;       /// error signal before windup correction
     F32 errorSum;                   /// error integral after windup correction
     F32 controlSignal;              /// actual control signal
-} PI_CONTROLLER_T;                  /// record for PI controller
+} PI_CONTROLLER_T;
 
 #define SET_CONTROLLER( c, id )     ((c) = &piControllers[id])          /// macro to set a local controller pointer to a given piController
 
@@ -52,6 +59,8 @@
     { 0.0, 0.0, 0.90, 0.10, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0 }   // PI_CONTROLLER_ID_DIALYSATE_FLOW
 };
 
+/**@}*/
+
 /*********************************************************************//**
  * @brief initializePIController
  * Initialize controller before operation. Make sure to call it before