diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.cpp b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
index fe26e7ffe3..bbc9b84d09 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.cpp
@@ -443,7 +443,7 @@ AP_InertialSensor::AP_InertialSensor() :
     _primary_accel(0),
     _hil_mode(false),
     _calibrating(false),
-    _log_raw_data(false),
+    _log_raw_bit(-1),
     _backends_detected(false),
     _dataflash(nullptr),
     _accel_cal_requires_reboot(false),
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor.h b/libraries/AP_InertialSensor/AP_InertialSensor.h
index 915215ca93..878f347d93 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor.h
+++ b/libraries/AP_InertialSensor/AP_InertialSensor.h
@@ -201,11 +201,8 @@ public:
     // get the accel filter rate in Hz
     uint8_t get_accel_filter_hz(void) const { return _accel_filter_cutoff; }
 
-    // pass in a pointer to DataFlash for raw data logging
-    void set_dataflash(DataFlash_Class *dataflash) { _dataflash = dataflash; }
-
-    // enable/disable raw gyro/accel logging
-    void set_raw_logging(bool enable) { _log_raw_data = enable; }
+    // indicate which bit in LOG_BITMASK indicates raw logging enabled
+    void set_log_raw_bit(uint32_t log_raw_bit) { _log_raw_bit = log_raw_bit; }
 
     // calculate vibration levels and check for accelerometer clipping (called by a backends)
     void calc_vibration_and_clipping(uint8_t instance, const Vector3f &accel, float dt);
@@ -393,6 +390,9 @@ private:
     uint8_t _primary_gyro;
     uint8_t _primary_accel;
 
+    // bitmask bit which indicates if we should log raw accel and gyro data
+    uint32_t _log_raw_bit;
+
     // has wait_for_sample() found a sample?
     bool _have_sample:1;
 
@@ -402,9 +402,6 @@ private:
     // are gyros or accels currently being calibrated
     bool _calibrating:1;
 
-    // should we log raw accel/gyro data?
-    bool _log_raw_data:1;
-
     bool _backends_detected:1;
 
     // the delta time in seconds for the last sample
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
index b9de06f090..ad4e973e05 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.cpp
@@ -409,3 +409,19 @@ void AP_InertialSensor_Backend::update_accel(uint8_t instance)
 
     _sem->give();
 }
+
+DataFlash_Class *AP_InertialSensor_Backend::get_dataflash() const
+{
+    DataFlash_Class *instance = DataFlash_Class::instance();
+    if (instance == nullptr) {
+        return nullptr;
+    }
+    if (_imu._log_raw_bit == (uint32_t)-1) {
+        // tracker does not set a bit
+        return nullptr;
+    }
+    if (!instance->should_log(_imu._log_raw_bit)) {
+        return nullptr;
+    }
+    return instance;
+}
diff --git a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.h b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.h
index 6f8cfa6956..25f54c03db 100644
--- a/libraries/AP_InertialSensor/AP_InertialSensor_Backend.h
+++ b/libraries/AP_InertialSensor/AP_InertialSensor_Backend.h
@@ -174,10 +174,9 @@ protected:
     // return the requested sample rate in Hz
     uint16_t get_sample_rate_hz(void) const;
 
-    // access to frontend dataflash
-    DataFlash_Class *get_dataflash(void) const {
-        return _imu._log_raw_data? _imu._dataflash : nullptr;
-    }
+    // access to frontend dataflash.  If raw-imu logging is not
+    // enabled, nullptr is returned
+    DataFlash_Class *get_dataflash() const;
 
     // common gyro update function for all backends
     void update_gyro(uint8_t instance);