diff --git a/src/main/build/debug.c b/src/main/build/debug.c
index a54abe20e3..410dcf6da3 100644
--- a/src/main/build/debug.c
+++ b/src/main/build/debug.c
@@ -90,4 +90,5 @@ const char * const debugModeNames[DEBUG_COUNT] = {
     "CRSF_LINK_STATISTICS_UPLINK",
     "CRSF_LINK_STATISTICS_PWR",
     "CRSF_LINK_STATISTICS_DOWN",
+    "BARO",
 };
diff --git a/src/main/build/debug.h b/src/main/build/debug.h
index c916e30721..3ac537eea3 100644
--- a/src/main/build/debug.h
+++ b/src/main/build/debug.h
@@ -106,6 +106,7 @@ typedef enum {
     DEBUG_CRSF_LINK_STATISTICS_UPLINK,
     DEBUG_CRSF_LINK_STATISTICS_PWR,
     DEBUG_CRSF_LINK_STATISTICS_DOWN,
+    DEBUG_BARO,
     DEBUG_COUNT
 } debugType_e;
 
diff --git a/src/main/drivers/barometer/barometer_bmp085.c b/src/main/drivers/barometer/barometer_bmp085.c
index d5758ce3c8..ac851c910a 100644
--- a/src/main/drivers/barometer/barometer_bmp085.c
+++ b/src/main/drivers/barometer/barometer_bmp085.c
@@ -39,7 +39,7 @@
 
 #ifdef USE_BARO
 
-#if defined(BARO_EOC_GPIO)
+#if defined(BARO_EOC_PIN)
 
 static IO_t eocIO;
 
@@ -53,7 +53,6 @@ void bmp085_extiHandler(extiCallbackRec_t* cb)
     isConversionComplete = true;
 }
 
-bool bmp085TestEOCConnected(const bmp085Config_t *config);
 # endif
 
 typedef struct {
@@ -164,7 +163,7 @@ bool bmp085Detect(const bmp085Config_t *config, baroDev_t *baro)
     bool ack;
     bool defaultAddressApplied = false;
 
-#if defined(BARO_EOC_GPIO)
+#if defined(BARO_EOC_PIN)
     IO_t eocIO = IO_NONE;
 #endif
 
@@ -174,14 +173,13 @@ bool bmp085Detect(const bmp085Config_t *config, baroDev_t *baro)
     bmp085InitXclrIO(config);
     BMP085_ON;   // enable baro
 
-#if defined(BARO_EOC_GPIO) && defined(USE_EXTI)
+#if defined(BARO_EOC_PIN) && defined(USE_EXTI)
     if (config && config->eocIO) {
         eocIO = IOGetByTag(config->eocIO);
         // EXTI interrupt for barometer EOC
         IOInit(eocIO, OWNER_BARO_EXTI, 0);
-        IOConfigGPIO(eocIO, Mode_IN_FLOATING);
-        EXTIHandlerInit(&bmp085_extiCallbackRec, bmp085_extiHandler);
-        EXTIConfig(eocIO, &bmp085_extiCallbackRec, NVIC_PRIO_BARO_EXTI, IOCFG_IN_FLOATING, EXTI_TRIGGER_RISING);
+        EXTIHandlerInit(&baro->exti, bmp085_extiHandler);
+        EXTIConfig(eocIO, &baro->exti, NVIC_PRIO_BARO_EXTI, IOCFG_IN_FLOATING, EXTI_TRIGGER_RISING);
         EXTIEnable(eocIO, true);
     }
 #else
@@ -215,15 +213,15 @@ bool bmp085Detect(const bmp085Config_t *config, baroDev_t *baro)
             baro->start_up = bmp085_start_up;
             baro->get_up = bmp085_get_up;
             baro->calculate = bmp085_calculate;
-#if defined(BARO_EOC_GPIO)
-            isEOCConnected = bmp085TestEOCConnected(config);
+#if defined(BARO_EOC_PIN)
+            isEOCConnected = bmp085TestEOCConnected(baro, config);
 #endif
             bmp085InitDone = true;
             return true;
         }
     }
 
-#if defined(BARO_EOC_GPIO)
+#if defined(BARO_EOC_PIN)
     if (eocIO)
         EXTIRelease(eocIO);
 #endif
@@ -292,7 +290,7 @@ static int32_t bmp085_get_pressure(uint32_t up)
 
 static void bmp085_start_ut(baroDev_t *baro)
 {
-#if defined(BARO_EOC_GPIO)
+#if defined(BARO_EOC_PIN)
     isConversionComplete = false;
 #endif
     busWriteRegister(&baro->busdev, BMP085_CTRL_MEAS_REG, BMP085_T_MEASURE);
@@ -302,7 +300,7 @@ static void bmp085_get_ut(baroDev_t *baro)
 {
     uint8_t data[2];
 
-#if defined(BARO_EOC_GPIO)
+#if defined(BARO_EOC_PIN)
     // return old baro value if conversion time exceeds datasheet max when EOC is connected
     if ((isEOCConnected) && (!isConversionComplete)) {
         return;
@@ -319,7 +317,7 @@ static void bmp085_start_up(baroDev_t *baro)
 
     ctrl_reg_data = BMP085_P_MEASURE + (bmp085.oversampling_setting << 6);
 
-#if defined(BARO_EOC_GPIO)
+#if defined(BARO_EOC_PIN)
     isConversionComplete = false;
 #endif
 
@@ -334,7 +332,7 @@ static void bmp085_get_up(baroDev_t *baro)
 {
     uint8_t data[3];
 
-#if defined(BARO_EOC_GPIO)
+#if defined(BARO_EOC_PIN)
     // return old baro value if conversion time exceeds datasheet max when EOC is connected
     if ((isEOCConnected) && (!isConversionComplete)) {
         return;
@@ -381,13 +379,13 @@ static void bmp085_get_cal_param(busDevice_t *busdev)
     bmp085.cal_param.md = (data[20] << 8) | data[21];
 }
 
-#if defined(BARO_EOC_GPIO)
-bool bmp085TestEOCConnected(const bmp085Config_t *config)
+#if defined(BARO_EOC_PIN)
+bool bmp085TestEOCConnected(baroDev_t *baro, const bmp085Config_t *config)
 {
     UNUSED(config);
 
     if (!bmp085InitDone && eocIO) {
-        bmp085_start_ut();
+        bmp085_start_ut(baro);
         delayMicroseconds(UT_DELAY * 2); // wait twice as long as normal, just to be sure
 
         // conversion should have finished now so check if EOC is high
diff --git a/src/main/drivers/barometer/barometer_bmp085.h b/src/main/drivers/barometer/barometer_bmp085.h
index 9f5a1e5530..7b3352dd66 100644
--- a/src/main/drivers/barometer/barometer_bmp085.h
+++ b/src/main/drivers/barometer/barometer_bmp085.h
@@ -32,8 +32,8 @@ typedef struct bmp085Config_s {
 bool bmp085Detect(const bmp085Config_t *config, baroDev_t *baro);
 void bmp085Disable(const bmp085Config_t *config);
 
-#if defined(BARO_EOC_GPIO)
-bool bmp085TestEOCConnected(const bmp085Config_t *config);
+#if defined(BARO_EOC_PIN)
+bool bmp085TestEOCConnected(baroDev_t *baro, const bmp085Config_t *config);
 #endif
 
 #ifdef UNIT_TEST
diff --git a/src/main/drivers/barometer/barometer_bmp280.c b/src/main/drivers/barometer/barometer_bmp280.c
index 4d660b5c66..62ebdd5905 100644
--- a/src/main/drivers/barometer/barometer_bmp280.c
+++ b/src/main/drivers/barometer/barometer_bmp280.c
@@ -52,8 +52,9 @@ typedef struct bmp280_calib_param_s {
     int16_t dig_P7; /* calibration P7 data */
     int16_t dig_P8; /* calibration P8 data */
     int16_t dig_P9; /* calibration P9 data */
-    int32_t t_fine; /* calibration t_fine data */
-} bmp280_calib_param_t;
+} __attribute__((packed)) bmp280_calib_param_t; // packed as we read directly from the device into this structure.
+
+STATIC_UNIT_TESTED int32_t t_fine; /* calibration t_fine data */
 
 static uint8_t bmp280_chip_id = 0;
 STATIC_UNIT_TESTED bmp280_calib_param_t bmp280_cal;
@@ -70,6 +71,8 @@ STATIC_UNIT_TESTED void bmp280_calculate(int32_t *pressure, int32_t *temperature
 
 void bmp280BusInit(busDevice_t *busdev)
 {
+    STATIC_ASSERT(sizeof(bmp280_calib_param_t) == BMP280_PRESSURE_TEMPERATURE_CALIB_DATA_LENGTH, bmp280_calibration_structure_incorrectly_packed);
+
 #ifdef USE_BARO_SPI_BMP280
     if (busdev->bustype == BUSTYPE_SPI) {
         IOHi(busdev->busdev_u.spi.csnPin); // Disable
@@ -125,7 +128,7 @@ bool bmp280Detect(baroDev_t *baro)
     }
 
     // read calibration
-    busReadRegisterBuffer(busdev, BMP280_TEMPERATURE_CALIB_DIG_T1_LSB_REG, (uint8_t *)&bmp280_cal, 24);
+    busReadRegisterBuffer(busdev, BMP280_TEMPERATURE_CALIB_DIG_T1_LSB_REG, (uint8_t *)&bmp280_cal, sizeof(bmp280_calib_param_t));
 
     // set oversampling + power mode (forced), and start sampling
     busWriteRegister(busdev, BMP280_CTRL_MEAS_REG, BMP280_MODE);
@@ -180,8 +183,8 @@ static int32_t bmp280_compensate_T(int32_t adc_T)
 
     var1 = ((((adc_T >> 3) - ((int32_t)bmp280_cal.dig_T1 << 1))) * ((int32_t)bmp280_cal.dig_T2)) >> 11;
     var2  = (((((adc_T >> 4) - ((int32_t)bmp280_cal.dig_T1)) * ((adc_T >> 4) - ((int32_t)bmp280_cal.dig_T1))) >> 12) * ((int32_t)bmp280_cal.dig_T3)) >> 14;
-    bmp280_cal.t_fine = var1 + var2;
-    T = (bmp280_cal.t_fine * 5 + 128) >> 8;
+    t_fine = var1 + var2;
+    T = (t_fine * 5 + 128) >> 8;
 
     return T;
 }
@@ -191,7 +194,7 @@ static int32_t bmp280_compensate_T(int32_t adc_T)
 static uint32_t bmp280_compensate_P(int32_t adc_P)
 {
     int64_t var1, var2, p;
-    var1 = ((int64_t)bmp280_cal.t_fine) - 128000;
+    var1 = ((int64_t)t_fine) - 128000;
     var2 = var1 * var1 * (int64_t)bmp280_cal.dig_P6;
     var2 = var2 + ((var1*(int64_t)bmp280_cal.dig_P5) << 17);
     var2 = var2 + (((int64_t)bmp280_cal.dig_P4) << 35);
diff --git a/src/main/sensors/barometer.c b/src/main/sensors/barometer.c
index 2eccc2d4b5..3b1fc60f0a 100644
--- a/src/main/sensors/barometer.c
+++ b/src/main/sensors/barometer.c
@@ -26,6 +26,8 @@
 
 #ifdef USE_BARO
 
+#include "build/debug.h"
+
 #include "common/maths.h"
 
 #include "pg/pg.h"
@@ -102,7 +104,7 @@ void pgResetFn_barometerConfig(barometerConfig_t *barometerConfig)
     barometerConfig->baro_spi_csn = IO_TAG(BARO_CS_PIN);
     barometerConfig->baro_i2c_device = I2C_DEV_TO_CFG(I2CINVALID);
     barometerConfig->baro_i2c_address = 0;
-#elif defined(DEFAULT_BARO_MS5611) || defined(DEFAULT_BARO_BMP280) || defined(DEFAULT_BARO_BMP085)||defined(DEFAULT_BARO_QMP6988)
+#elif defined(DEFAULT_BARO_MS5611) || defined(DEFAULT_BARO_BMP280) || defined(DEFAULT_BARO_BMP085) || defined(DEFAULT_BARO_QMP6988)
     // All I2C devices shares a default config with address = 0 (per device default)
     barometerConfig->baro_bustype = BUSTYPE_I2C;
     barometerConfig->baro_i2c_device = I2C_DEV_TO_CFG(BARO_I2C_INSTANCE);
@@ -183,7 +185,7 @@ bool baroDetect(baroDev_t *dev, baroSensor_e baroHardwareToUse)
         {
             const bmp085Config_t *bmp085Config = NULL;
 
-#if defined(BARO_XCLR_GPIO) && defined(BARO_EOC_GPIO)
+#if defined(BARO_XCLR_PIN) && defined(BARO_EOC_PIN)
             static const bmp085Config_t defaultBMP085Config = {
                 .xclrIO = IO_TAG(BARO_XCLR_PIN),
                 .eocIO = IO_TAG(BARO_EOC_PIN),
@@ -324,6 +326,10 @@ uint32_t baroUpdate(void)
 {
     static barometerState_e state = BAROMETER_NEEDS_SAMPLES;
 
+    if (debugMode == DEBUG_BARO) {
+        debug[0] = state;
+    }
+
     switch (state) {
         default:
         case BAROMETER_NEEDS_SAMPLES:
@@ -340,6 +346,13 @@ uint32_t baroUpdate(void)
             baro.baroPressure = baroPressure;
             baro.baroTemperature = baroTemperature;
             baroPressureSum = recalculateBarometerTotal(barometerConfig()->baro_sample_count, baroPressureSum, baroPressure);
+
+            if (debugMode == DEBUG_BARO) {
+                debug[1] = baroTemperature;
+                debug[2] = baroPressure;
+                debug[3] = baroPressureSum;
+            }
+
             state = BAROMETER_NEEDS_SAMPLES;
             return baro.dev.ut_delay;
         break;
diff --git a/src/test/unit/baro_bmp280_unittest.cc b/src/test/unit/baro_bmp280_unittest.cc
index cd9b2b4256..52d7ddd0cc 100644
--- a/src/test/unit/baro_bmp280_unittest.cc
+++ b/src/test/unit/baro_bmp280_unittest.cc
@@ -27,6 +27,7 @@ void bmp280_calculate(int32_t *pressure, int32_t *temperature);
 
 extern uint32_t bmp280_up;
 extern uint32_t bmp280_ut;
+extern int32_t t_fine; /* calibration t_fine data */
 
 typedef struct bmp280_calib_param_s {
     uint16_t dig_T1; /* calibration T1 data */
@@ -41,8 +42,7 @@ typedef struct bmp280_calib_param_s {
     int16_t dig_P7; /* calibration P7 data */
     int16_t dig_P8; /* calibration P8 data */
     int16_t dig_P9; /* calibration P9 data */
-    int32_t t_fine; /* calibration t_fine data */
-} bmp280_calib_param_t;
+} __attribute__((packed)) bmp280_calib_param_t; // packed as we read directly from the device into this structure.
 
 bmp280_calib_param_t bmp280_cal;
 }
@@ -58,6 +58,7 @@ TEST(baroBmp280Test, TestBmp280Calculate)
     int32_t pressure, temperature;
     bmp280_up = 415148; // Digital pressure value
     bmp280_ut = 519888; // Digital temperature value
+    t_fine = 0;
 
     // and
     bmp280_cal.dig_T1 = 27504;
@@ -87,6 +88,7 @@ TEST(baroBmp280Test, TestBmp280CalculateHighP)
     int32_t pressure, temperature;
     bmp280_up = 215148; // Digital pressure value
     bmp280_ut = 519888; // Digital temperature value
+    t_fine = 0;
 
     // and
     bmp280_cal.dig_T1 = 27504;
@@ -116,6 +118,7 @@ TEST(baroBmp280Test, TestBmp280CalculateZeroP)
     int32_t pressure, temperature;
     bmp280_up = 415148; // Digital pressure value
     bmp280_ut = 519888; // Digital temperature value
+    t_fine = 0;
 
     // and
     bmp280_cal.dig_T1 = 27504;