Index: firmware/App/Services/Reservoirs.c
===================================================================
diff -u -r7d293e18ea5ac0fce443c68525100e44df80b4fd -r353d01d31bc69d4d1901ff09097ee610bb1c9dbc
--- firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision 7d293e18ea5ac0fce443c68525100e44df80b4fd)
+++ firmware/App/Services/Reservoirs.c	(.../Reservoirs.c)	(revision 353d01d31bc69d4d1901ff09097ee610bb1c9dbc)
@@ -20,6 +20,7 @@
 #include "LoadCell.h"
 #include "MessageSupport.h"
 #include "ModeDrain.h"
+#include "ModeFill.h"
 #include "ModeGenIdle.h"
 #include "OperationModes.h"
 #include "Pressures.h"
@@ -37,7 +38,7 @@
 // ********** private definitions **********
 
 #define MIN_RESERVOIR_VOLUME_ML         0                                               ///< Minimum reservoir volume in mL.
-#define DEFAULT_FILL_VOLUME_ML          1700                                            ///< Default fill volume for treatment in mL.
+#define DEFAULT_FILL_VOLUME_ML          1500                                            ///< Default fill volume for treatment in mL.
 #define MAX_FILL_VOLUME_ML              MAX_RESERVOIR_VOLUME_ML                         ///< Maximum fill volume in mL.
 #define DEFAULT_DRAIN_VOLUME_ML         0                                               ///< Default drain volume in mL.
 #define MAX_DRAIN_VOLUME_ML             MAX_RESERVOIR_VOLUME_ML                         ///< Maximum drain volume in mL.
@@ -48,10 +49,29 @@
 
 #define RESERVOIR_DATA_PUB_INTERVAL     ( MS_PER_SECOND / TASK_GENERAL_INTERVAL )       ///< interval (ms/task time) at which the reservoir data is published on the CAN bus.
 
-#define MAX_REDUNDANT_LOAD_CELL_DIFF    50.0                                            ///< Maximum difference in redundant load cells when determing if fill completed.
+#define MAX_REDUNDANT_LOAD_CELL_DIFF    50.0                                            ///< Maximum difference in redundant load cells when determing if fill completed.
 
-// ********** private data **********
-
+
+// TODO add doxygen comments
+#define RESERVOIR_TEMPERATURE_TAU_C_PER_MIN              -0.512                                                           ///< Reservoir temperature time constant C/min.
+#define ULTRAFILTER_TEMPERATURE_TAU_C_PER_MIN            -0.512                                                          ///< Ultrafilter temperature time constant C/min.
+#define ULTRAFILTER_VOLUME_ML                                      700
+
+
+// ********** private data **********
+
+// TODO yes we should add all the doxygen comments soon
+// TODO add doxygen comments
+typedef struct
+{
+    U32 timeReservoirCycleMS;
+    F32 timeUFDecayMS;
+    F32 tempUFFill;
+    F32 tempRerservoirStartFill;
+
+} HEATERS_TEMPERATURE_CALC_DATA_T;
+
+static HEATERS_TEMPERATURE_CALC_DATA_T heatersTempCalc;
 static U32 reservoirDataPublicationTimerCounter = 0;                                    ///< used to schedule reservoir data publication to CAN bus.
 
 static OVERRIDE_U32_T activeReservoir = { 0, 0, 0, 0 };                                 ///< The active reservoir that the DG is filling/draining/etc.
@@ -69,11 +89,16 @@
 static U32 reservoirWeightUnchangeStartTime[ NUM_OF_DG_RESERVOIRS ] = { 0, 0 };         ///< The reservoirs' weight start time when weight stop decreasing.
 static BOOL tareLoadCellRequest;                                                        ///< Flag indicates if load cell tare has been requested by HD.
 static DG_RESERVOIR_VOLUME_RECORD_T reservoirsCalRecord;                                ///< DG reservoirs non-volatile record.
-static F32 targetFillFlowRateLPM;
+static F32 targetFillFlowRateLPM;                                                       ///< Target fill flow rate in L/min.
 
+static const F32 ULTRAFILTER_TAU_C_PER_MS = ULTRAFILTER_TEMPERATURE_TAU_C_PER_MIN * SEC_PER_MIN * MS_PER_SECOND;
+static const F32 RESERVOIR_TAU_C_PER_MS   = RESERVOIR_TEMPERATURE_TAU_C_PER_MIN * SEC_PER_MIN * MS_PER_SECOND;
+
 // ********** private function prototypes **********
 
-static BOOL processCalibrationData( void );
+static BOOL processCalibrationData( void );
+static F32  getPrimaryHeaterTargetTemperature( void );
+static F32  getTrimmerHeaterTargetTemperature( void );
 
 /*********************************************************************//**
  * @brief
@@ -88,7 +113,7 @@
     activeReservoir.data     = (U32)DG_RESERVOIR_1;
     fillVolumeTargetMl.data  = DEFAULT_FILL_VOLUME_ML;
     drainVolumeTargetMl.data = DEFAULT_DRAIN_VOLUME_ML;
-    targetFillFlowRateLPM    = 0.0;
+    targetFillFlowRateLPM    = 0.0;
 }
 
 /*********************************************************************//**
@@ -270,9 +295,9 @@
         if ( fillToVolMl < MAX_FILL_VOLUME_ML )
         {
             fillVolumeTargetMl.data = fillToVolMl;
+            cmdResponse.rejected    = FALSE;
 
             requestNewOperationMode( DG_MODE_FILL );
-            cmdResponse.rejected = FALSE;
         }
         else
         {
@@ -284,6 +309,7 @@
         cmdResponse.rejectCode = DG_CMD_REQUEST_REJECT_REASON_INVALID_MODE;
     }
 
+    // Set the fill flow rate
     targetFillFlowRateLPM = fillTargetLPM;
 
     sendCommandResponseMsg( &cmdResponse );
@@ -451,19 +477,53 @@
 
 /*********************************************************************//**
  * @brief
+ * The getTargetFillVolumeML function returns the target fill volume in mL.
+ * @details Inputs: none
+ * @details Outputs: none
+ * @return target fill volume in mL
+ *************************************************************************/
+U32 getTargetFillVolumeML( void )
+{
+    U32 targetFill = fillVolumeTargetMl.data;
+
+    if ( OVERRIDE_KEY == fillVolumeTargetMl.override )
+    {
+        targetFill = fillVolumeTargetMl.ovData;
+    }
+
+    return targetFill;
+}
+
+/*********************************************************************//**
+ * @brief
  * The getTargetFillFlowRateLPM function returns the target fill flow rate
  * in L/min.
  * @details Inputs: none
  * @details Outputs: none
  * @return target fill flow rate in L/min
  *************************************************************************/
-F32 getTargetFillFlowRateLPM( void )
+F32  getTargetFillFlowRateLPM( void )
 {
     return targetFillFlowRateLPM;
 }
 
 /*********************************************************************//**
  * @brief
+ * The setActiveReservoirCycleTime function sets the active reservoir cycle
+ * time in milliseconds.
+ * @details Inputs: none
+ * @details Outputs: heatersTemperatureCalcData
+ * @return none
+ *************************************************************************/
+void setHeatersTargetTemperature( TARGET_TEMPS_AND_TIME_PAYLOAD_T targets )
+{
+    heatersTempCalc.timeReservoirCycleMS = targets.activeReservoirCycleTimeMS;
+
+    setHeaterTargetTemperature( DG_PRIMARY_HEATER, getPrimaryHeaterTargetTemperature() );
+}
+
+/*********************************************************************//**
+ * @brief
  * The getReservoirsCalRecord function returns the reservoirs' calibration
  * record.
  * @details Inputs: reservoirsCalRecord
@@ -617,7 +677,42 @@
     return status;
 }
 
+/*********************************************************************//**
+ * @brief
+ * The getPrimaryHeaterTargetTemperature function calculates the primary
+ * heater target temperature and returns target temperature value.
+ * @details Inputs: none
+ * @details Outputs: heatersTempCalc
+ * @return TRUE if the calibration record is valid, otherwise FALSE
+ *************************************************************************/
+static F32 getPrimaryHeaterTargetTemperature( void )
+{
+    F32 targetTemp      = 0.0;
+    F32 targetFillVolML = getTargetFillVolumeML();
+    F32 timeFillMS      = ( getTargetFillFlowRateLPM() * ML_PER_LITER ) / targetFillVolML; // TODO target flow can come from RO pump too
 
+    heatersTempCalc.timeUFDecayMS = (F32)heatersTempCalc.timeReservoirCycleMS - timeFillMS;
+    heatersTempCalc.tempUFFill    = getLastFillTemperature() + ( heatersTempCalc.timeUFDecayMS * ULTRAFILTER_TAU_C_PER_MS );
+
+    F32 ultrafilterPart = ( ULTRAFILTER_VOLUME_ML / targetFillVolML ) * heatersTempCalc.tempUFFill;
+    F32 fillPart        = ( ( ( targetFillVolML - ULTRAFILTER_VOLUME_ML ) / targetFillVolML ) * getAvgFillTemperature() );
+
+    heatersTempCalc.tempRerservoirStartFill = ultrafilterPart + fillPart;
+
+    return targetTemp;
+}
+
+static F32 getTrimmerHeaterTargetTemperature( void )
+{
+    F32 targetTemp      = 0.0;
+    F32 targetFillVolML = getTargetFillVolumeML();
+    F32 timeHalfFillMS  = ( getTargetFillFlowRateLPM() * ML_PER_LITER * 0.5 ) / targetFillVolML; // TODO target flow can come from RO pump
+
+
+    return targetTemp;
+}
+
+
 /*************************************************************************
  *                       TEST SUPPORT FUNCTIONS
  *************************************************************************/
@@ -681,8 +776,8 @@
 
     if ( TRUE == isTestingActivated() )
     {
-        result = TRUE;
-        fillVolumeTargetMl.ovData = value;
+        result                      = TRUE;
+        fillVolumeTargetMl.ovData   = value;
         fillVolumeTargetMl.override = OVERRIDE_KEY;
     }
 
@@ -703,9 +798,9 @@
 
     if ( TRUE == isTestingActivated() )
     {
-        result = TRUE;
+        result                      = TRUE;
         fillVolumeTargetMl.override = OVERRIDE_RESET;
-        fillVolumeTargetMl.ovData = fillVolumeTargetMl.ovInitData;
+        fillVolumeTargetMl.ovData   = fillVolumeTargetMl.ovInitData;
     }
 
     return result;