Index: firmware/App/Controllers/BloodLeak.c
===================================================================
diff -u -re55f9fe6ad322e30fbc53a6857b19a95a3107706 -rdd1a9a6f5e43a5da27f4d51f56388f7d019cc43d
--- firmware/App/Controllers/BloodLeak.c	(.../BloodLeak.c)	(revision e55f9fe6ad322e30fbc53a6857b19a95a3107706)
+++ firmware/App/Controllers/BloodLeak.c	(.../BloodLeak.c)	(revision dd1a9a6f5e43a5da27f4d51f56388f7d019cc43d)
@@ -7,8 +7,8 @@
 *
 * @file    BloodLeak.c
 *
-* @author  (last)      Sean Nash
-* @date    (last)      12-Nov-2021
+* @author  (last)      Dara Navaei
+* @date    (last)      04-Jan-2022
 *
 * @author  (original)  Peman Montazemi
 * @date    (original)  18-Mar-2021
@@ -56,6 +56,12 @@
 
 #define BLOOD_LEAK_MIN_WAIT_TIME_2_GET_CAL_MS ( 2 * MS_PER_SECOND )                              ///< Blood leak minimum wait time to get calibration in milliseconds.
 
+// TODO remove after zeroing was fixed
+#define BLOOD_LEAK_ZERO_SENSOR_SEQ_LENGTH     5                                                  ///< Blood leak zero sensor sequence length.
+#define BLOOD_LEAK_ZERO_Z_CHAR_ASCII          90                                                 ///< Blood leak zero sensor 'Z' command in ascii.
+#define BLOOD_LEAK_ZERO_FIFO_STOP_INDEX       2                                                  ///< Blood leak zero sensor stop writing to FIFO command.
+// TODO remove after zeroing was fixed
+
 /// Defined states for the blood leak detector state machine.
 typedef enum BloodLeakStates
 {
@@ -84,7 +90,7 @@
 static OVERRIDE_U32_T bloodLeakDataPublishInterval = { BLOOD_LEAK_PUB_INTERVAL,
                                                        BLOOD_LEAK_PUB_INTERVAL, 0, 0 };          ///< Interval (in ms) at which to publish blood leak data to CAN bus.
 static U32 bloodLeakDataPublicationTimerCounter = 0;                                             ///< Timer counter used to schedule blood leak data publication to CAN bus.
-static U32 bloodLeakUARTCmdIndex;                                                                ///< Blood leak UART command index.
+static U32 bloodLeakUARTCmdIndex = 0;                                                            ///< Blood leak UART command index.
 static U32 bloodLeakSetPointSeqLength = 0;                                                       ///< Blood leak set point sequence actual length.
 static U08 bloodLeakSetPointSequence[ BLOOD_LEAK_SET_POINT_SEQ_MAX_LENGTH ];                     ///< Blood leak set point sequence array.
 static U32 bloodLeakWait2ReadSetPointCounter = 0;                                                ///< Blood leak wait to read delay counter.
@@ -100,6 +106,15 @@
                                                                                    BLOOD_LEAK_UART_COMM_ACTIVE_HIGH,
                                                                                    BLOOD_LEAK_UART_COMM_ACTIVE_LOW };
 
+// TODO remove after zeroing was fixed
+/// Blood leak zero sensor sequence array.
+static const U08 BLOOD_LEAK_ZERO_SNSR_SEQUENCE[ BLOOD_LEAK_ZERO_SENSOR_SEQ_LENGTH ] = { BLOOD_LEAK_ZERO_Z_CHAR_ASCII,
+                                                                                        BLOOD_LEAK_CARRIAGE_RETURN_ASCII,
+                                                                                        BLOOD_LEAK_STOP_WRITE_FIFO_COMMAND,
+                                                                                        BLOOD_LEAK_UART_COMM_ACTIVE_HIGH,
+                                                                                        BLOOD_LEAK_UART_COMM_ACTIVE_LOW };
+// TODO remove after zeroing was fixed
+
 // ********** private function prototypes **********
 
 static BLOOD_LEAK_STATES_T handleBloodLeakStartupState( void );
@@ -229,6 +244,7 @@
 void zeroBloodLeak( void )
 {
     bloodLeakZeroRequested = TRUE;
+    bloodLeakUARTCmdIndex  = 0;
 }
 
 /*********************************************************************//**
@@ -325,7 +341,6 @@
             activateAlarmNoData( ALARM_ID_HD_BLOOD_LEAK_SENSOR_SET_POINT_SET_FAILURE );
 #endif
         }
-
     }
     else
     {
@@ -398,7 +413,7 @@
         state = BLOOD_LEAK_ZERO_STATE;
         bloodLeakZeroRequested = FALSE;
 
-        setFPGABloodLeakZero();
+        //setFPGABloodLeakZero(); // DEBUG_DENALI
         bloodLeakZeroStartTime = getMSTimerCount();
     }
 
@@ -417,24 +432,40 @@
 {
     BLOOD_LEAK_STATES_T state = BLOOD_LEAK_ZERO_STATE;
 
-    if ( TRUE == FPGABloodLeakZeroDetected() )
+    if ( bloodLeakUARTCmdIndex < BLOOD_LEAK_ZERO_SENSOR_SEQ_LENGTH )
     {
-        bloodLeakSelfTestStatus = SELF_TEST_STATUS_IN_PROGRESS;
-        clearFPGABloodLeakZero();
-#ifndef IGNORE_BLOOD_LEAK_SELF_TEST
-        setFPGABloodLeakSelfTest();
-        state = BLOOD_LEAK_SELF_TEST_STATE;
-#else
-        state = BLOOD_LEAK_NORMAL_STATE;
-#endif
-        bloodLeakSelfTestStartTime = getMSTimerCount();
+        U08 command = BLOOD_LEAK_ZERO_SNSR_SEQUENCE[ bloodLeakUARTCmdIndex ];
+
+        if ( bloodLeakUARTCmdIndex <= BLOOD_LEAK_ZERO_FIFO_STOP_INDEX )
+        {
+            setFPGABloodLeakUARTTransmit( (U08)command );
+        }
+        else
+        {
+            setFPGABloodLeakUARTControl( (U08)command );
+        }
+
+        bloodLeakUARTCmdIndex++;
     }
     else
     {
-        if ( TRUE == didTimeout( bloodLeakZeroStartTime, BLOOD_LEAK_TIMEOUT_MS ) )
+        if ( TRUE == FPGABloodLeakZeroDetected() )
         {
-            activateAlarmNoData( ALARM_ID_HD_BLOOD_LEAK_FAULT );
+            state = BLOOD_LEAK_SELF_TEST_STATE;
+            bloodLeakSelfTestStatus = SELF_TEST_STATUS_IN_PROGRESS;
+            clearFPGABloodLeakZero();
+            setFPGABloodLeakSelfTest();
+            bloodLeakSelfTestStartTime = getMSTimerCount();
         }
+        else
+        {
+            if ( TRUE == didTimeout( bloodLeakZeroStartTime, BLOOD_LEAK_TIMEOUT_MS ) )
+            {
+    #ifndef IGNORE_BLOOD_LEAK_ALARM
+                activateAlarmNoData( ALARM_ID_HD_BLOOD_LEAK_FAULT );
+    #endif
+            }
+        }
     }
 
     return state;
@@ -534,7 +565,7 @@
         state = BLOOD_LEAK_ZERO_STATE;
         bloodLeakZeroRequested = FALSE;
 
-        setFPGABloodLeakZero();
+        //setFPGABloodLeakZero(); // DEBUG_DENALI
         bloodLeakZeroStartTime = getMSTimerCount();
     }