Index: firmware/App/Modes/BloodPrime.c
===================================================================
diff -u -r6b870cd0699bb3ee22b93981d51373a6c2d56162 -rdb22e9d530c5c9d62b02e6dcc72ed96fb67c165a
--- firmware/App/Modes/BloodPrime.c	(.../BloodPrime.c)	(revision 6b870cd0699bb3ee22b93981d51373a6c2d56162)
+++ firmware/App/Modes/BloodPrime.c	(.../BloodPrime.c)	(revision db22e9d530c5c9d62b02e6dcc72ed96fb67c165a)
@@ -23,6 +23,7 @@
 #include "ModeTreatment.h"
 #include "ModeTreatmentParams.h"
 #include "OperationModes.h"
+#include "SyringePump.h"
 #include "SystemCommMessages.h"
 #include "TaskGeneral.h"
 #include "Utilities.h"
@@ -66,7 +67,7 @@
 static U32  bloodPrimePublishTimerCtr;                                      ///< Timer counter for determining interval for blood prime status to be published.
 
 static F32  cumulativeBloodPrimeVolume_mL;                                  ///< Total cumulative blood prime volume (in mL).
-static U32  bloodPrimeMotorCount;                                           ///< The cumulative sum of BP motor encoder counts used for independent blood prime volume check.
+static S32  bloodPrimeMotorCount;                                           ///< The cumulative sum of BP motor encoder counts used for independent blood prime volume check.
 static U32  bloodPrimeLastMotorCount;                                       ///< The last BP motor encoder count read for independent blood prime volume check.
 static F32  bloodPrimeVolumeDelivered_Safety;                               ///< The cumulative independent blood prime volume (in mL) calculated so far.
 
@@ -150,7 +151,8 @@
 
     // Ensure dialysate outlet and Heparin pumps are stopped
     signalDialOutPumpHardStop();
-    // TODO - stop Heparin pump
+    stopSyringePump();
+
     // start blood and dialysate inlet pumps
     setBloodPumpTargetFlowRate( BLOOD_PRIME_INIT_BP_FLOW_RATE_ML_MIN, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_OPEN_LOOP );
     setDialInPumpTargetFlowRate( DIALYSATE_FLOW_RATE_FOR_RECIRC, MOTOR_DIR_FORWARD, PUMP_CONTROL_MODE_CLOSED_LOOP );
@@ -203,14 +205,11 @@
 static BLOOD_PRIME_STATE_T handleBloodPrimeRampState( void )
 {
     BLOOD_PRIME_STATE_T result = BLOOD_PRIME_RAMP_STATE;
-    U32 bldPumpMotorCount = getBloodPumpMotorCount();
-    U32 bldPumpMotorDelta = u32DiffWithWrap( bloodPrimeLastMotorCount, bldPumpMotorCount );
 
     // update blood prime volume delivered so far
     cumulativeBloodPrimeVolume_mL += ( getMeasuredBloodFlowRate() * BLOOD_PRIME_FLOW_INTEGRATOR );
     // update independent calculated safety volume delivered so far
-    bloodPrimeMotorCount += bldPumpMotorDelta;
-    bloodPrimeLastMotorCount = bldPumpMotorCount;
+    bloodPrimeMotorCount = u32BiDiffWithWrap( bloodPrimeLastMotorCount, getBloodPumpMotorCount() ) / BP_HALL_EDGE_COUNTS_PER_REV;
     bloodPrimeVolumeDelivered_Safety = ( (F32)bloodPrimeMotorCount * VOLUME_PER_BP_MOTOR_REV_ML );  // TODO - include upstream pressure compensation to this calc
 
     // Has blood prime completed?