Index: firmware/App/Drivers/PressureSensor.c
===================================================================
diff -u -re2e51b0219db0132cebb6f65f3dbd803e1f01e30 -rfefb47e88a5285e99498efb830fdceb9e95c2c3e
--- firmware/App/Drivers/PressureSensor.c	(.../PressureSensor.c)	(revision e2e51b0219db0132cebb6f65f3dbd803e1f01e30)
+++ firmware/App/Drivers/PressureSensor.c	(.../PressureSensor.c)	(revision fefb47e88a5285e99498efb830fdceb9e95c2c3e)
@@ -20,6 +20,7 @@
 #include "Messaging.h"
 #include "PersistentAlarm.h"
 #include "PressureSensor.h"
+#include "TemperatureSensors.h"
 
 /**
  *  @addtogroup PressureSensor
@@ -29,17 +30,39 @@
 // ********** private definitions **********
 
 #define PRES_SENSORS_COUNT_ERROR_TIMEOUT_MS         ( 2 * MS_PER_SECOND )                               ///< Pressure sensors read and error count timeout in milliseconds.
+#define ONE_BAR_TO_MILLI_BAR                        1000                                                ///< 1 bar to milli-bar conversion.
+#define COUNTS_TO_MILLI_BAR                         100                                                 ///< Counts to milli-bar conversion.
+#define BAR_TO_MMHG                                 ( 750.062F )                                        ///< Conversion factor for converting bar to mmHg.
+
+/// Barometric sensor conversion coefficients
+typedef struct
+{
+    U16 pressureSensitivity;                                                                            ///< Barometric sensor pressure sensitivity constant.
+    U16 pressureOffset;                                                                                 ///< Barometric sensor pressure offset constant.
+    U16 pressureSensitivityTempCoeff;                                                                   ///< Barometric sensor pressure sensitivity temperature coefficient.
+    U16 pressureOffsetTempCoeff;                                                                        ///< Barometric sensor pressure offset temperature coefficient.
+} BARO_SENSOR_CONSTS_T;
 
 // ********** private data **********
 
 static OVERRIDE_F32_T currentPressureReadings[ NUM_OF_PRESSURE_SENSORS ];                               ///< Current pressure sensor pressure readings (overrideable).
 static OVERRIDE_F32_T currentPresTempReadings[ NUM_OF_PRESSURE_SENSORS ];                               ///< Current pressure sensor temperature readings (overrideable).
 static OVERRIDE_U32_T lastPressureReadCounter[ NUM_OF_PRESSURE_SENSORS ];                               ///< Last pressure sensor read count (Overrideable).
 static OVERRIDE_U32_T lastPressureErrorCounter[ NUM_OF_PRESSURE_SENSORS ];                              ///< Last pressure sensor error count (Overrideable).
+static BARO_SENSOR_CONSTS_T baroConvConsts;                                                             ///< Barometric sensor conversion constants.
+
+static const U32 TWO_TO_POWER_OF_6  = ( 1 << 6 );                                                       ///< 2^6.
+static const U32 TWO_TO_POWER_OF_7  = ( 1 << 7 );                                                       ///< 2^7.
+static const U32 TWO_TO_POWER_OF_15 = ( 1 << 15 );                                                      ///< 2^15.
+static const U32 TWO_TO_POWER_OF_16 = ( 1 << 16 );                                                      ///< 2^16.
+static const U32 TWO_TO_POWER_OF_17 = ( 1 << 17 );                                                      ///< 2^17.
+static const U32 TWO_TO_POWER_OF_21 = ( 1 << 21 );                                                      ///< 2^21.
 
 // ********** private function prototypes **********
 
 static void checkPressureSensors( void );
+static F32 convertBaroPressureReading2mmHg( U32 rawPressure );
+static F32 calculateBaroPressure( U32 pressure );
 
 /*********************************************************************//**
  * @brief
@@ -76,6 +99,12 @@
         lastPressureErrorCounter[ i ].override = OVERRIDE_RESET;
     }
 
+    //Initialize baro variable
+    baroConvConsts.pressureOffset               = 0;
+    baroConvConsts.pressureOffsetTempCoeff      = 0;
+    baroConvConsts.pressureSensitivity          = 0;
+    baroConvConsts.pressureSensitivityTempCoeff = 0;
+
     // Initialize the FPGA persistent alarms
     initFPGAPersistentAlarm( FPGA_PERS_ERROR_HYDRAULICS_OUTLET_PRESSURE, ALARM_ID_DD_HYD_OUTLET_PRES_TIMEOUT_FAULT,
                              PRES_SENSORS_COUNT_ERROR_TIMEOUT_MS, PRES_SENSORS_COUNT_ERROR_TIMEOUT_MS );
@@ -110,6 +139,7 @@
     currentPressureReadings[ PRESSURE_SENSOR_SPENT_DIALYSATE ].data = convertPressureReading2mmHg( getFPGAPDsRawPressure() );
     currentPressureReadings[ PRESSURE_SENSOR_FRESH_DIALYSATE ].data   = convertPressureReading2mmHg( getFPGAPDfRawPressure() );
     currentPressureReadings[ PRESSURE_SENSOR_TRANSMEMBRANE ].data = convertPressureReading2mmHg( getFPGAPtmRawPressure() );
+    currentPressureReadings[ PRESSURE_SENSOR_BAROMETRIC ].data = convertBaroPressureReading2mmHg( getFPGABaroPressure() );
 
     // Update and convert raw pressure sensor temperatures to deg C
     currentPresTempReadings[ PRESSURE_SENSOR_HYDRAULICS_OUTLET ].data = convertPressureTempReading2DegC( getFPGAPnRawTemperature() );
@@ -137,6 +167,52 @@
 
 /*********************************************************************//**
  * @brief
+ * The convertBaroPressureReading2mmHg function converts the raw pressure counts
+ * in to mmHg unit.
+ * @details \b Inputs: FPGA
+ * @details \b Outputs: baroConvConsts
+ * @param rawPressure the raw baro sensor reading from FPGA.
+ * @return the converted baro pressure (in mmHg).
+ *************************************************************************/
+static F32 convertBaroPressureReading2mmHg( U32 rawPressure )
+{
+    F32 baroPressure = 0.0F;
+
+    baroConvConsts.pressureSensitivity          = getFPGABaroPressureSensitivity();
+    baroConvConsts.pressureSensitivityTempCoeff = getFPGABaroTempCoeffOfPressSensitvity();
+    baroConvConsts.pressureOffset               = getFPGABaroPressureOffset();
+    baroConvConsts.pressureOffsetTempCoeff      = getFPGABaroTempCoeffOfPressOffset();
+    baroPressure                                = calculateBaroPressure( rawPressure );
+
+    return baroPressure;
+}
+
+/*********************************************************************//**
+ * @brief
+ * The calculateBaroPressure function performs the required calculations
+ * to compute the baro pressure readings.
+ * @details \b Inputs: baroConvConsts
+ * @details \b Outputs: none
+ * @param pressure the raw baro sensor reading from FPGA.
+ * @return converted baro pressure (in mmHg).
+ *************************************************************************/
+static F32 calculateBaroPressure( U32 pressure )
+{
+    S32 tempDiff        = getBaroSensorTemperatureDiff();
+    S64 tempOffset      = ( baroConvConsts.pressureOffsetTempCoeff * tempDiff ) / TWO_TO_POWER_OF_6;
+    S64 presOffset      = baroConvConsts.pressureOffset * TWO_TO_POWER_OF_17;
+    S64 offset          = presOffset + tempOffset;
+    S64 tempSensitivity = ( baroConvConsts.pressureSensitivityTempCoeff * tempDiff ) / TWO_TO_POWER_OF_7;
+    S64 presSensitivity = baroConvConsts.pressureSensitivity * TWO_TO_POWER_OF_16;
+    S64 sensitivity     = tempSensitivity + presSensitivity;
+    S32 pres            = (S32)( ( ( pressure * sensitivity ) / TWO_TO_POWER_OF_21 ) - offset ) / TWO_TO_POWER_OF_15;
+    F32 presmmHg        = ( (F32)pres / (F32)( COUNTS_TO_MILLI_BAR * ONE_BAR_TO_MILLI_BAR ) ) * BAR_TO_MMHG;
+
+    return presmmHg;
+}
+
+/*********************************************************************//**
+ * @brief
  * The checkPressureSensors function checks the read and error counters for
  * each pressure sensor.
  * @details \b Alarm: ALARM_ID_DD_HYD_OUTLET_PRES_TIMEOUT_FAULT if the