Index: firmware/App/Controllers/BalancingChamber.c
===================================================================
diff -u -r7278aeac8fdd894067a05c3bd3a177d38c0b0803 -ra08213c3d131203c21554d743c3ccb02575b70da
--- firmware/App/Controllers/BalancingChamber.c	(.../BalancingChamber.c)	(revision 7278aeac8fdd894067a05c3bd3a177d38c0b0803)
+++ firmware/App/Controllers/BalancingChamber.c	(.../BalancingChamber.c)	(revision a08213c3d131203c21554d743c3ccb02575b70da)
@@ -208,8 +208,12 @@
  *************************************************************************/
 void transitionToBalChamberFill( void )
 {
+    printf("[TRACE3] transitionToBalChamberFill ENTRY: tick=%lu priorPeriod=%lu priorLastQd=%.2f priorSwOnly=%d\n",
+               getMSTimerCount(), balChamberSwitchingPeriod, lastTdDialysateFlowrate, balanceChamberSwitchingOnly);
     initBalanceChamber();
     updateBalChamberSwitchingPeriod();
+    printf("[TRACE3b] transitionToBalChamberFill EXIT: tick=%lu newPeriod=%lu newLastQd=%.2f\n",
+               getMSTimerCount(), balChamberSwitchingPeriod, lastTdDialysateFlowrate);
 }
 
 /*********************************************************************//**
@@ -223,18 +227,21 @@
 void updateBalChamberSwitchingPeriod( void )
 {
     F32 tdDialysateFlowrate = getTDDialysateFlowrate();
-
+    printf("[TRACE4] updateBalChamberSwitchingPeriod: tick=%lu lastQd=%.4f newQd=%.4f isSwActive=%d execState=%d\n",
+               getMSTimerCount(), lastTdDialysateFlowrate, tdDialysateFlowrate, isBalChamberSwitchingActive, balChamberExecState);
     if ( lastTdDialysateFlowrate != tdDialysateFlowrate )
     {
         // Defer Qd timing update to FillEnd at end of the current BC switch
         if ( ( TRUE == isBalChamberSwitchingActive ) && ( BAL_CHAMBER_STATE_IDLE != balChamberExecState ) )
         {
             pendingTdDialysateFlowrate               = tdDialysateFlowrate;
             isBalChamberSwitchingPeriodUpdatePending = TRUE;
+            printf("[TRACE4a] Qd CHANGED branch taken\n");
         }
         // Apply immediately when BC is inactive or still idle
         else
         {
+            printf("[TRACE4b] Qd UNCHANGED branch taken -- period NOT recalculated, stays at %lu\n", balChamberSwitchingPeriod);
             pendingTdDialysateFlowrate               = tdDialysateFlowrate;
             isBalChamberSwitchingPeriodUpdatePending = TRUE;
             applyBalChamberSwitchingPeriod( pendingTdDialysateFlowrate );
@@ -298,6 +305,8 @@
 
         // finish the balancing chamber fill 50 ms prior completing the regular cycle time.
         balChamberSwitchingPeriod -= 1;
+        printf("[TRACE5] Period calculated: tick=%lu switchFreq=%.4f period=%lu\n",
+                       getMSTimerCount(), getBalChamberSwitchingFreq(), balChamberSwitchingPeriod);
 
         //Update last td dialysate flow rate
         lastTdDialysateFlowrate = tdDialysateFlowrate;
@@ -314,6 +323,8 @@
         //Testing
         balChamberValveClosePeriod = balChamberSwitchingPeriod;
         balChamberValveClosePeriod -= 1;   // Close valves prior 50 msecond for testing
+        printf("[TRACE5b] ValveClosePeriod set: tick=%lu period=%lu closePeriod=%lu (CHECK FOR UNDERFLOW)\n",
+                       getMSTimerCount(), balChamberSwitchingPeriod, balChamberValveClosePeriod);
 
         currentBalChamberFillCounter      = 0;
         currentBalChamberSwitchingCounter = 0;
@@ -890,6 +901,8 @@
     {
         if ( TRUE == isBalChamberSwitchingPeriodUpdatePending )
         {
+            printf("[TRACE7] BC forced IDLE via isBalChamberSwitchingOffRequested: tick=%lu D51=%.2f execState=%d\n",
+                      getMSTimerCount(), getFilteredPressure(D51_PRES), balChamberExecState);
             applyBalChamberSwitchingPeriod( pendingTdDialysateFlowrate );
             scheduleFirstCycleRelaxAfterQdApply();
         }
@@ -1161,6 +1174,8 @@
     {
         if ( TRUE == isBalChamberSwitchingPeriodUpdatePending )
         {
+            printf("[TRACE7] BC forced IDLE via isBalChamberSwitchingOffRequested: tick=%lu D51=%.2f execState=%d\n",
+                      getMSTimerCount(), getFilteredPressure(D51_PRES), balChamberExecState);
             applyBalChamberSwitchingPeriod( pendingTdDialysateFlowrate );
             scheduleFirstCycleRelaxAfterQdApply();
         }
@@ -1477,6 +1492,12 @@
     return isBalChamberFillInProgress;
 }
 
+
+BOOL getBalancingChamberStatus( void )
+{
+    return isBalChamberSwitchingActive;
+}
+
 /*********************************************************************//**
  * @brief
  * The getBalChamberSwitchingFreq function gets the balancing chamber switching
@@ -1616,6 +1637,8 @@
     return balancingError;
 }
 
+
+
 /*********************************************************************//**
  * @brief
  * The publishBalChamberData function broadcasts the balancing chamber