diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5d06de6963..bfa2f191d2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -53,18 +53,31 @@ set(ECL_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR})
 if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
 	# ECL standalone build
 	add_definitions(-DECL_STANDALONE)
+	set(ECL_STANDALONE 1)
 
 	add_custom_target(prebuild_targets)
 
-	add_compile_options(
-		-pedantic
-	
-		-Wall
-		-Wextra
-		-Werror
+	if(MSVC)
+		add_compile_options(
+			/W4
+			/WX
 
-		-Wno-unused-parameter
-	)
+			/D_USE_MATH_DEFINES
+
+			/wd4100 # warning C4100: unreferenced formal parameter
+			/wd4244 # warning C4244: '=': conversion from 'double' to 'int32_t', possible loss of data
+			)
+	elseif(CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX)
+		add_compile_options(
+			-pedantic
+		
+			-Wall
+			-Wextra
+			-Werror
+
+			-Wno-unused-parameter
+		)
+	endif()
 
 	# fetch latest matrix from github
 	include(ExternalProject)
@@ -87,7 +100,7 @@ if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
 	if(BUILD_TESTING)
 
 		add_custom_target(check
-			COMMAND env CTEST_OUTPUT_ON_FAILURE=1 ${CMAKE_CTEST_COMMAND}
+			COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C Debug
 			DEPENDS ecl_EKF
 			USES_TERMINAL
 		)
diff --git a/EKF/ekf.cpp b/EKF/ekf.cpp
index 2fa6d7810e..8f14c9c9ed 100644
--- a/EKF/ekf.cpp
+++ b/EKF/ekf.cpp
@@ -227,9 +227,9 @@ bool Ekf::initialiseFilter()
 	}
 
 	// check to see if we have enough measurements and return false if not
-	bool hgt_count_fail = _hgt_counter <= 2 * _obs_buffer_length;
-	bool mag_count_fail = _mag_counter <= 2 * _obs_buffer_length;
-	bool ev_count_fail = ((_params.fusion_mode & MASK_USE_EVPOS) || (_params.fusion_mode & MASK_USE_EVYAW)) && (_ev_counter <= 2 * _obs_buffer_length);
+	bool hgt_count_fail = _hgt_counter <= 2u * _obs_buffer_length;
+	bool mag_count_fail = _mag_counter <= 2u * _obs_buffer_length;
+	bool ev_count_fail = ((_params.fusion_mode & MASK_USE_EVPOS) || (_params.fusion_mode & MASK_USE_EVYAW)) && (_ev_counter <= 2u * _obs_buffer_length);
 
 	if (hgt_count_fail || mag_count_fail || ev_count_fail) {
 		return false;
diff --git a/EKF/tests/CMakeLists.txt b/EKF/tests/CMakeLists.txt
index 696b1e467e..7f7dc8e019 100644
--- a/EKF/tests/CMakeLists.txt
+++ b/EKF/tests/CMakeLists.txt
@@ -31,7 +31,7 @@
 #
 ############################################################################
 
-if(BUILD_TESTING)
+if(BUILD_TESTING AND ECL_STANDALONE)
 	add_subdirectory(base)
 	
 	if(EKF_PYTHON_TESTS)
diff --git a/EKF/tests/pytest/CMakeLists.txt b/EKF/tests/pytest/CMakeLists.txt
index b804b78570..f531ed977d 100644
--- a/EKF/tests/pytest/CMakeLists.txt
+++ b/EKF/tests/pytest/CMakeLists.txt
@@ -33,33 +33,35 @@
 
 if(EKF_PYTHON_TESTS)
 
+	# pip3 install -r requirements.txt 
+
 	add_custom_target(ecl_EKF_pytest
-		COMMAND env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/ekf_test.py --verbose
+		COMMAND ${CMAKE_COMMAND} -E env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/ekf_test.py --verbose
 		DEPENDS ecl_EKF _ecl_EKF
 		USES_TERMINAL
 	)
 
 	add_custom_target(ecl_EKF_pytest-quick
-		COMMAND env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/ekf_test.py --quick --verbose
+		COMMAND ${CMAKE_COMMAND} -E env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/ekf_test.py --quick --verbose
 		DEPENDS ecl_EKF _ecl_EKF
 		USES_TERMINAL
 	)
 
 	add_custom_target(ecl_EKF_pytest-benchmark
-		COMMAND env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/ekf_test.py --benchmark
+		COMMAND ${CMAKE_COMMAND} -E env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/ekf_test.py --benchmark
 		DEPENDS ecl_EKF _ecl_EKF
 		USES_TERMINAL
 	)
 
 	# requires python3-tk
 	add_custom_target(ecl_EKF_pytest-plots
-		COMMAND env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/ekf_test.py --plots
+		COMMAND ${CMAKE_COMMAND} -E env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/ekf_test.py --plots
 		DEPENDS ecl_EKF _ecl_EKF
 		USES_TERMINAL
 	)
 
 	add_custom_target(ecl_EKF_pytest-lint
-		COMMAND env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/lint.py
+		COMMAND ${CMAKE_COMMAND} -E env PYTHONPATH=${CMAKE_BINARY_DIR}/EKF/swig/python ${CMAKE_CURRENT_SOURCE_DIR}/lint.py
 		DEPENDS ecl_EKF _ecl_EKF
 		WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
 		USES_TERMINAL
diff --git a/geo/geo.h b/geo/geo.h
index ff1164d1dc..2289e28331 100644
--- a/geo/geo.h
+++ b/geo/geo.h
@@ -84,13 +84,11 @@ struct globallocal_converter_reference_s {
 	bool init_done;
 };
 
-__BEGIN_DECLS
-
 /**
  * Checks if global projection was initialized
  * @return true if map was initialized before, false else
  */
-bool map_projection_global_initialized(void);
+bool map_projection_global_initialized();
 
 /**
  * Checks if projection given as argument was initialized
@@ -308,5 +306,3 @@ float _wrap_180(float bearing);
 float _wrap_360(float bearing);
 float _wrap_pi(float bearing);
 float _wrap_2pi(float bearing);
-
-__END_DECLS
diff --git a/geo_lookup/geo_mag_declination.h b/geo_lookup/geo_mag_declination.h
index 0b958a62d7..a48f5e4397 100644
--- a/geo_lookup/geo_mag_declination.h
+++ b/geo_lookup/geo_mag_declination.h
@@ -41,8 +41,6 @@
 
 #pragma once
 
-__BEGIN_DECLS
-
 // Return magnetic declination in degrees
 float get_mag_declination(float lat, float lon);
 
@@ -51,5 +49,3 @@ float get_mag_inclination(float lat, float lon);
 
 // return magnetic field strength in mTesla
 float get_mag_strength(float lat, float lon);
-
-__END_DECLS
diff --git a/mathlib/mathlib.h b/mathlib/mathlib.h
index c8d0d7677a..04a1803257 100644
--- a/mathlib/mathlib.h
+++ b/mathlib/mathlib.h
@@ -47,10 +47,6 @@
 #define M_PI_F 3.14159265358979323846f
 #endif
 
-#ifndef M_PI
-#define M_PI (3.14159265358979323846f)
-#endif
-
 #ifndef M_PI_2_F
 #define M_PI_2_F (M_PI / 2.0f)
 #endif
diff --git a/tecs/tecs.cpp b/tecs/tecs.cpp
index 95a564446f..1cce0f35df 100644
--- a/tecs/tecs.cpp
+++ b/tecs/tecs.cpp
@@ -40,6 +40,9 @@ using math::constrain;
 using math::max;
 using math::min;
 
+static constexpr float DT_MIN = 0.001f;	///< minimum allowed value of _dt (sec)
+static constexpr float DT_MAX = 1.0f;	///< max value of _dt allowed before a filter state reset is performed (sec)
+
 /**
  * @file tecs.cpp
  *
@@ -55,10 +58,9 @@ void TECS::update_vehicle_state_estimates(float airspeed, const matrix::Dcmf &ro
 		const matrix::Vector3f &accel_body, bool altitude_lock, bool in_air,
 		float altitude, bool vz_valid, float vz, float az)
 {
-
 	// calculate the time lapsed since the last update
 	uint64_t now = ecl_absolute_time();
-	float dt = max((now - _state_update_timestamp), static_cast<uint64_t>(0)) * 1.0e-6f;
+	float dt = constrain((now - _state_update_timestamp) * 1.0e-6f, DT_MIN, DT_MAX);
 
 	bool reset_altitude = false;
 
@@ -148,12 +150,7 @@ void TECS::_update_speed_states(float airspeed_setpoint, float indicated_airspee
 {
 	// Calculate the time in seconds since the last update and use the default time step value if out of bounds
 	uint64_t now = ecl_absolute_time();
-	float dt = max((now - _speed_update_timestamp), UINT64_C(0)) * 1.0e-6f;
-
-	if (dt < DT_MIN || dt > DT_MAX) {
-		dt = DT_DEFAULT;
-
-	}
+	const float dt = constrain((now - _speed_update_timestamp) * 1.0e-6f, DT_MIN, DT_MAX);
 
 	// Convert equivalent airspeed quantities to true airspeed
 	_EAS_setpoint = airspeed_setpoint;
@@ -168,14 +165,12 @@ void TECS::_update_speed_states(float airspeed_setpoint, float indicated_airspee
 
 	} else {
 		_EAS = indicated_airspeed;
-
 	}
 
 	// If first time through or not flying, reset airspeed states
 	if (_speed_update_timestamp == 0 || !_in_air) {
 		_tas_rate_state = 0.0f;
 		_tas_state = (_EAS * EAS2TAS);
-
 	}
 
 	// Obtain a smoothed airspeed estimate using a second order complementary filter
@@ -579,10 +574,9 @@ void TECS::update_pitch_throttle(const matrix::Dcmf &rotMat, float pitch, float
 				 float EAS_setpoint, float indicated_airspeed, float eas_to_tas, bool climb_out_setpoint, float pitch_min_climbout,
 				 float throttle_min, float throttle_max, float throttle_cruise, float pitch_limit_min, float pitch_limit_max)
 {
-
 	// Calculate the time since last update (seconds)
 	uint64_t now = ecl_absolute_time();
-	_dt = max((now - _pitch_update_timestamp), UINT64_C(0)) * 1.0e-6f;
+	_dt = constrain((now - _pitch_update_timestamp) * 1e-6f, DT_MIN, DT_MAX);
 
 	// Set class variables from inputs
 	_throttle_setpoint_max = throttle_max;
diff --git a/tecs/tecs.h b/tecs/tecs.h
index bdd7ecefa2..31cc8b23e4 100644
--- a/tecs/tecs.h
+++ b/tecs/tecs.h
@@ -266,9 +266,7 @@ private:
 
 	// time steps (non-fixed)
 	float _dt{DT_DEFAULT};						///< Time since last update of main TECS loop (sec)
-	static constexpr float DT_MIN = 0.001f;				///< minimum allowed value of _dt (sec)
 	static constexpr float DT_DEFAULT = 0.02f;			///< default value for _dt (sec)
-	static constexpr float DT_MAX = 1.0f;				///< max value of _dt allowed before a filter state reset is performed (sec)
 
 	// controller mode logic
 	bool _underspeed_detected{false};				///< true when an underspeed condition has been detected
diff --git a/validation/data_validator.h b/validation/data_validator.h
index 8d6a489756..ca380f86b4 100644
--- a/validation/data_validator.h
+++ b/validation/data_validator.h
@@ -183,9 +183,12 @@ private:
 	float _rms[dimensions];			/**< root mean square error */
 	float _value[dimensions];		/**< last value */
 	float _vibe[dimensions];		/**< vibration level, in sensor unit */
-	float _value_equal_count;		/**< equal values in a row */
-	float _value_equal_count_threshold; /**< when to consider an equal count as a problem */
+
+	unsigned _value_equal_count;		/**< equal values in a row */
+	unsigned _value_equal_count_threshold;	/**< when to consider an equal count as a problem */
+
 	DataValidator *_sibling;		/**< sibling in the group */
+
 	static const constexpr unsigned NORETURN_ERRCOUNT = 10000;	/**< if the error count reaches this value, return sensor as invalid */
 	static const constexpr float ERROR_DENSITY_WINDOW = 100.0f; 	/**< window in measurement counts for errors */
 	static const constexpr unsigned VALUE_EQUAL_COUNT_DEFAULT = 100;	/**< if the sensor value is the same (accumulated also between axes) this many times, flag it */