Index: firmware/App/Modes/ModePreTreat.c
===================================================================
diff -u -r30f049651877229042e3f8700c8596e5b9a1e0f4 -r766708fceb0bdf1af8c7897df29d4f5036bfd3db
--- firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 30f049651877229042e3f8700c8596e5b9a1e0f4)
+++ firmware/App/Modes/ModePreTreat.c	(.../ModePreTreat.c)	(revision 766708fceb0bdf1af8c7897df29d4f5036bfd3db)
@@ -15,16 +15,10 @@
 *
 ***************************************************************************/
 
-#include "AirTrap.h"
-#include "AlarmLamp.h"
-#include "BloodFlow.h"
-#include "DialInFlow.h"
-#include "DialOutFlow.h"
-#include "Buttons.h"
+#include "ModePreTreat.h"
 #include "OperationModes.h"
+#include "Prime.h"
 #include "SystemCommMessages.h"
-#include "ModePreTreat.h"
-#include "SystemCommMessages.h"
 
 /**
  *  @addtogroup HDPreTreatmentMode
@@ -33,10 +27,17 @@
 
 // ********** private data **********
 
-static BOOL treatStartReqReceived = FALSE;                      ///< Flag indicates user requests treatment begin.
+static BOOL treatStartReqReceived = FALSE;                              ///< Flag indicates user requests treatment begin.
 
+static PRE_TREATMENT_MODE_STATE_T currentPreTreatmentState;             ///< Current state of pre-treatment mode state machine.
+
 // ********** private function prototypes **********
 
+static PRE_TREATMENT_MODE_STATE_T handleSelfTestNoCartState( void );
+static PRE_TREATMENT_MODE_STATE_T handleSelfTestDryState( void );
+static PRE_TREATMENT_MODE_STATE_T handlePrimeState( void );
+static PRE_TREATMENT_MODE_STATE_T handlePatientConnectionState( void );
+
 /*********************************************************************//**
  * @brief
  * The initPreTreatmentMode function initializes the Pre-Treatment Mode module.
@@ -46,6 +47,7 @@
 *************************************************************************/
 void initPreTreatmentMode( void )
 {
+    currentPreTreatmentState = PRE_TREATMENT_START_STATE;
 }
 
 /*********************************************************************//**
@@ -64,6 +66,8 @@
     setAlarmUserActionEnabled( ALARM_USER_ACTION_RESUME, TRUE );
     setAlarmUserActionEnabled( ALARM_USER_ACTION_RINSEBACK, FALSE );
     setAlarmUserActionEnabled( ALARM_USER_ACTION_END_TREATMENT, TRUE );
+
+    currentPreTreatmentState = PRE_TREATMENT_START_STATE;
 }
 
 /*********************************************************************//**
@@ -75,22 +79,62 @@
 *************************************************************************/
 U32 execPreTreatmentMode( void )
 {
-    BOOL stop = isStopButtonPressed();
-
-    if ( TRUE == treatStartReqReceived )
+    // execute mode state machine
+    switch ( currentPreTreatmentState )
     {
-        requestNewOperationMode( MODE_TREA );
+        case PRE_TREATMENT_START_STATE:
+            cmdStartDG();
+            cmdSetDGDialysateTargetTemps( 39.0, 37.0 );
+            currentPreTreatmentState = PRE_TREATMENT_WATER_SAMPLE_STATE;
+            break;
+
+        case PRE_TREATMENT_WATER_SAMPLE_STATE:
+            currentPreTreatmentState = PRE_TREATMENT_SELF_TEST_NO_CART_STATE;
+            break;
+
+        case PRE_TREATMENT_SELF_TEST_NO_CART_STATE:
+            currentPreTreatmentState = handleSelfTestNoCartState();
+            break;
+
+        case PRE_TREATMENT_CART_INSTALL_STATE:
+            currentPreTreatmentState = PRE_TREATMENT_SELF_TEST_DRY_STATE;
+            break;
+
+        case PRE_TREATMENT_SELF_TEST_DRY_STATE:
+            currentPreTreatmentState = handleSelfTestDryState();
+            break;
+
+        case PRE_TREATMENT_PRIME_STATE:
+            currentPreTreatmentState = handlePrimeState();
+            break;
+
+        case PRE_TREATMENT_SELF_TEST_WET_STATE:
+            currentPreTreatmentState = PRE_TREATMENT_RECIRC_STATE;
+            break;
+
+        case PRE_TREATMENT_RECIRC_STATE:
+            currentPreTreatmentState = PRE_TREATMENT_PATIENT_CONNECTION_STATE;
+            break;
+
+        case PRE_TREATMENT_PATIENT_CONNECTION_STATE:
+            currentPreTreatmentState = handlePatientConnectionState();
+            break;
+
+        default:
+            currentPreTreatmentState = PRE_TREATMENT_START_STATE;
+            SET_ALARM_WITH_2_U32_DATA( ALARM_ID_HD_SOFTWARE_FAULT, SW_FAULT_ID_MODE_PRE_TREATMENT_INVALID_STATE, (U32)currentPreTreatmentState );
+            break;
     }
 
-    return 0; // TODO - return current state
+    return (U32)currentPreTreatmentState;
 }
 
 /*********************************************************************//**
  * @brief
  * The signalUserBeginningTreatment function handles user start of a
  * treatment.
  * @details Inputs: none
- * @details Outputs: requested mode transition to treatment mode
+ * @details Outputs: treatStartReqReceived, send response to treatment start
  * @return TRUE if signal accepted, FALSE if not
  *************************************************************************/
 BOOL signalUserBeginningTreatment( void )
@@ -121,4 +165,83 @@
     // TODO - implement
 }
 
+/*********************************************************************//**
+ * @brief
+ * The handleSelfTestNoCartState function handles self-test with no cartrige.
+ * @details Inputs: none
+ * @details Outputs: home blood pump and dialysate pumps
+ * @return current state (sub-mode)
+ *************************************************************************/
+static PRE_TREATMENT_MODE_STATE_T handleSelfTestNoCartState( void )
+{
+    // TODO: Prompt user to close door
+
+    homeBloodPump();
+    homeDialInPump();
+    homeDialOutPump();
+
+    // TODO: Prompt user to open door
+
+    return PRE_TREATMENT_CART_INSTALL_STATE;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The handleSelfTestDryState function handles dry self-test.
+ * @details Inputs: none
+ * @details Outputs: transition to prime sub-mode when blood pump finished homing
+ * @return current state (sub-mode)
+ *************************************************************************/
+static PRE_TREATMENT_MODE_STATE_T handleSelfTestDryState( void )
+{
+    PRE_TREATMENT_MODE_STATE_T state = PRE_TREATMENT_CART_INSTALL_STATE;
+
+    if ( FALSE == isBloodPumpRunning() )
+    {
+        transitionToPrime();
+        state = PRE_TREATMENT_PRIME_STATE;
+    }
+
+    return state;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The handlePrimeState function handles priming the blood and dialysate circuits.
+ * @details Inputs: none
+ * @details Outputs: transition to self test wet state after priming passed
+ * @return current state (sub-mode)
+ *************************************************************************/
+static PRE_TREATMENT_MODE_STATE_T handlePrimeState( void )
+{
+    PRE_TREATMENT_MODE_STATE_T state = PRE_TREATMENT_PRIME_STATE;
+
+    execPrime();
+
+    if ( TRUE == isPrimingPassed() )
+    {
+        state = PRE_TREATMENT_SELF_TEST_WET_STATE;
+    }
+
+    return state;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The handlePatientConnectionState function handles patient connection state
+ * during pre-treatment mode.
+ * @details Inputs: none
+ * @details Outputs: requested mode transition to treatment mode
+ * @return current state (sub-mode)
+ *************************************************************************/
+static PRE_TREATMENT_MODE_STATE_T handlePatientConnectionState( void )
+{
+    if ( TRUE == treatStartReqReceived )
+    {
+        requestNewOperationMode( MODE_TREA );
+    }
+
+    return PRE_TREATMENT_PATIENT_CONNECTION_STATE;
+}
+
 /**@}*/