diff --git a/CMakeLists.txt b/CMakeLists.txt
index f6c257f922..ca8a1f519a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,8 +36,8 @@ cmake_minimum_required(VERSION 3.0)
 project(ECL CXX)
 
 if (NOT CMAKE_BUILD_TYPE)
-    set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING "Build type" FORCE)
-    message(STATUS "set build type to ${CMAKE_BUILD_TYPE}")
+	set(CMAKE_BUILD_TYPE "RelWithDebInfo" CACHE STRING "Build type" FORCE)
+	message(STATUS "set build type to ${CMAKE_BUILD_TYPE}")
 endif()
 
 set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug;Release;RelWithDebInfo;MinSizeRel;Coverage")
@@ -60,11 +60,11 @@ option(COV_HTML "Display html for coverage" OFF)
 option(ECL_ASAN "Enable ECL address sanitizer" OFF)
 
 set(CMAKE_CXX_FLAGS_COVERAGE
-    "--coverage -fprofile-arcs -ftest-coverage -fno-default-inline -fno-inline -fno-inline-small-functions -fno-elide-constructors"
-    CACHE STRING "Flags used by the C++ compiler during coverage builds" FORCE)
+	"--coverage -fprofile-arcs -ftest-coverage -fno-default-inline -fno-inline -fno-inline-small-functions -fno-elide-constructors"
+	CACHE STRING "Flags used by the C++ compiler during coverage builds" FORCE)
 set(CMAKE_EXE_LINKER_FLAGS_COVERAGE
-    "--coverage -ftest-coverage -lgcov"
-    CACHE STRING "Flags used for linking binaries during coverage builds" FORCE)
+	"--coverage -ftest-coverage -lgcov"
+	CACHE STRING "Flags used for linking binaries during coverage builds" FORCE)
 mark_as_advanced(CMAKE_CXX_FLAGS_COVERAGE CMAKE_C_FLAGS_COVERAGE CMAKE_EXE_LINKER_FLAGS_COVERAGE)
 
 
@@ -92,18 +92,17 @@ if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
 			-pedantic
 
 			-Wall
-			-Wextra
+			#-Wextra	# This was causing an issue in the swig stuff
 			-Werror
 
 			-Wno-missing-field-initializers # ignore for GCC 4.8 support
 		)
 	endif()
 
-	# testing
-	include(CTest)
-	enable_testing()
-
 	if(BUILD_TESTING)
+
+		include(CTest)
+
 		option(ECL_TESTS "Build ECL tests" ON)
 
 		add_custom_target(check
@@ -118,6 +117,8 @@ if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
 			# swig requires -fPIC
 			set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 		endif()
+
+
 	endif()
 
 	# fetch latest matrix from github
@@ -164,28 +165,36 @@ add_subdirectory(geo)
 add_subdirectory(geo_lookup)
 add_subdirectory(l1)
 add_subdirectory(tecs)
-add_subdirectory(validation)
+if(BUILD_TESTING)
+	add_subdirectory(validation)
+	add_subdirectory(test)
+endif()
 
 #=============================================================================
 # Coverage
 #
 if (${CMAKE_BUILD_TYPE} STREQUAL "Coverage")
 
-    add_custom_target(coverage
-        COMMAND ${CMAKE_CTEST_COMMAND}
-        COMMAND lcov --capture --directory . --output-file coverage.info
-        COMMAND lcov --remove coverage.info '/usr/*' --output-file coverage.info # filter out system
-        COMMAND lcov --remove coverage.info 'build/coverage_build/EKF/swig/*' --output-file coverage.info
-        COMMAND lcov --summary coverage.info
-        WORKING_DIRECTORY ${CMAKE_BUILD_DIR}
-        DEPENDS check
-        )
+	add_custom_target(coverage
+		COMMAND ${CMAKE_CTEST_COMMAND}
+		COMMAND lcov --capture --directory . --output-file coverage.info
+		COMMAND lcov --remove coverage.info  --output-file coverage.info '/usr/*' '${CMAKE_BINARY_DIR}/*' # filter out system
+		COMMAND lcov --summary coverage.info
+		WORKING_DIRECTORY ${CMAKE_BUILD_DIR}
+		DEPENDS check
+	)
 
-    add_custom_target(coverage_html
-        COMMAND genhtml coverage.info --output-directory out
-        WORKING_DIRECTORY ${CMAKE_BUILD_DIR}
-        DEPENDS coverage
-        )
+	add_custom_target(coverage_html
+		COMMAND genhtml coverage.info --output-directory out
+		WORKING_DIRECTORY ${CMAKE_BUILD_DIR}
+		DEPENDS coverage
+	)
+
+	add_custom_target(coverage_html_view
+		COMMAND x-www-browser out/index.html
+		WORKING_DIRECTORY ${CMAKE_BUILD_DIR}
+		DEPENDS coverage_html
+	)
 
 endif()
 
@@ -223,17 +232,3 @@ if(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
 	endif()
 endif()
 
-
-enable_testing()
-include_directories(${GTEST_INCLUDE_DIR})
-add_subdirectory("/usr/src/gtest" ${CMAKE_BINARY_DIR}/gtest)
-
-set(SRCS
-   test/main.cpp
-   test/test_example.cpp
-   )
-add_executable(TestECL ${SRCS})
-
-target_include_directories(TestECL PRIVATE ${GTEST_INCLUDE_DIRS})
-target_link_libraries(TestECL gtest gtest_main)
-add_test(NAME TestECL COMMAND TestECL)
diff --git a/EKF/CMakeLists.txt b/EKF/CMakeLists.txt
index 3a51f8b4ba..ea458d67cb 100644
--- a/EKF/CMakeLists.txt
+++ b/EKF/CMakeLists.txt
@@ -58,10 +58,10 @@ set_target_properties(ecl_EKF PROPERTIES PUBLIC_HEADER "ekf.h")
 
 target_compile_options(ecl_EKF PRIVATE -fno-associative-math)
 
-#if(EKF_PYTHON_TESTS)
-#	add_subdirectory(swig)
-#endif()
+if(EKF_PYTHON_TESTS)
+	add_subdirectory(swig)
+endif()
 
-#if(BUILD_TESTING)
-#	add_subdirectory(tests)
-#endif()
+if(BUILD_TESTING)
+	add_subdirectory(tests)
+endif()
diff --git a/Makefile b/Makefile
index 41f7c52a66..c1abb47f5e 100644
--- a/Makefile
+++ b/Makefile
@@ -78,7 +78,7 @@ SRC_DIR := $(shell dirname $(realpath $(lastword $(MAKEFILE_LIST))))
 define cmake-build
 +@$(eval BUILD_DIR = $(SRC_DIR)/build/$@$(BUILD_DIR_SUFFIX))
 +@if [ $(PX4_CMAKE_GENERATOR) = "Ninja" ] && [ -e $(BUILD_DIR)/Makefile ]; then rm -rf $(BUILD_DIR); fi
-+@if [ ! -e $(BUILD_DIR)/CMakeCache.txt ]; then mkdir -p $(BUILD_DIR) && cd $(BUILD_DIR) && cmake $(2) -G"$(PX4_CMAKE_GENERATOR)" $(CMAKE_ARGS) $(3) $(4) || (rm -rf $(BUILD_DIR)); fi
++@if [ ! -e $(BUILD_DIR)/CMakeCache.txt ]; then mkdir -p $(BUILD_DIR) && cd $(BUILD_DIR) && cmake $(2) -G"$(PX4_CMAKE_GENERATOR)" $(CMAKE_ARGS) $(3) $(4) $(5) || (rm -rf $(BUILD_DIR)); fi
 +@(cd $(BUILD_DIR) && $(PX4_MAKE) $(PX4_MAKE_ARGS) $(ARGS))
 endef
 
@@ -98,19 +98,19 @@ doxygen:
 .PHONY: test_build test test_EKF
 
 test_build:
-	@$(call cmake-build,$@,$(SRC_DIR), "-DEKF_PYTHON_TESTS=ON")
+	@$(call cmake-build,$@,$(SRC_DIR), "-DEKF_PYTHON_TESTS=ON", "-DBUILD_TESTING=ON")
 
 test: test_build
 	@cmake --build $(SRC_DIR)/build/test_build --target check
 
 test_EKF: test_build
 	@cmake --build $(SRC_DIR)/build/test_build --target ecl_EKF_pytest-quick
-	
+
 test_EKF_plots: test_build
 	@cmake --build $(SRC_DIR)/build/test_build --target ecl_EKF_pytest-plots
 
 test_build_asan:
-	@$(call cmake-build,$@,$(SRC_DIR), "-DECL_ASAN=ON")
+	@$(call cmake-build,$@,$(SRC_DIR), "-DECL_ASAN=ON", "-DBUILD_TESTING=ON")
 
 test_asan: test_build_asan
 	@cmake --build $(SRC_DIR)/build/test_build_asan --target check
@@ -119,21 +119,24 @@ test_asan: test_build_asan
 # --------------------------------------------------------------------
 
 coverage_build:
-	@$(call cmake-build,$@,$(SRC_DIR), "-DCMAKE_BUILD_TYPE=Coverage", "-DEKF_PYTHON_TESTS=ON")
-	
+	@$(call cmake-build,$@,$(SRC_DIR), "-DCMAKE_BUILD_TYPE=Coverage", "-DEKF_PYTHON_TESTS=ON", "-DBUILD_TESTING=ON")
+
 coverage: coverage_build
 	@cmake --build $(SRC_DIR)/build/coverage_build --target coverage
 
-coverage_html: coverage
+coverage_html: coverage_build
 	@cmake --build $(SRC_DIR)/build/coverage_build --target coverage_html
 
+coverage_html_view: coverage_build
+	@cmake --build $(SRC_DIR)/build/coverage_build --target coverage_html_view
+
 # Cleanup
 # --------------------------------------------------------------------
 .PHONY: clean distclean
 
 clean:
 	@rm -rf $(SRC_DIR)/build
-	
+
 distclean:
 	@git clean -ff -x -d .
 
diff --git a/EKF/tests/ringbuffer/CMakeLists.txt b/test/CMakeLists.txt
similarity index 85%
rename from EKF/tests/ringbuffer/CMakeLists.txt
rename to test/CMakeLists.txt
index f8a29555c5..dcf546c26f 100644
--- a/EKF/tests/ringbuffer/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,6 +1,6 @@
 ############################################################################
 #
-#   Copyright (c) 2015-2018 ECL Development Team. All rights reserved.
+#   Copyright (c) 2019 ECL Development Team. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
@@ -31,9 +31,14 @@
 #
 ############################################################################
 
-add_executable(ecl_EKF_tests_ringbuffer ringbuffer.cpp)
-target_link_libraries(ecl_EKF_tests_ringbuffer ecl_EKF)
+include(gtest.cmake)
 
-add_test(NAME ecl_EKF_tests_ringbuffer
-	COMMAND ecl_EKF_tests_ringbuffer
-	)
+set(SRCS
+   main.cpp
+   test_EKF_basics.cpp
+   )
+add_executable(ECL_GTESTS ${SRCS})
+
+target_link_libraries(ECL_GTESTS gtest_main ecl_EKF)
+
+add_test(NAME ECL_GTESTS COMMAND ECL_GTESTS)
diff --git a/test/CMakeLists.txt.in b/test/CMakeLists.txt.in
new file mode 100644
index 0000000000..a119c417b4
--- /dev/null
+++ b/test/CMakeLists.txt.in
@@ -0,0 +1,19 @@
+cmake_minimum_required(VERSION 2.8.4)
+
+project(googletest-download NONE)
+
+include(ExternalProject)
+ExternalProject_Add(googletest
+	URL https://github.com/google/googletest/archive/8b6d3f9c4a774bef3081195d422993323b6bb2e0.zip
+	SOURCE_DIR "${CMAKE_CURRENT_BINARY_DIR}/googletest-src"
+	BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/googletest-build"
+	CONFIGURE_COMMAND ""
+	BUILD_COMMAND ""
+	INSTALL_COMMAND ""
+	TEST_COMMAND ""
+	# Wrap download, configure and build steps in a script to log output
+    LOG_DOWNLOAD ON
+    LOG_CONFIGURE ON
+    LOG_BUILD ON
+)
+
diff --git a/test/gtest.cmake b/test/gtest.cmake
new file mode 100644
index 0000000000..8e1bff7661
--- /dev/null
+++ b/test/gtest.cmake
@@ -0,0 +1,50 @@
+############################################################################
+#
+# Copyright (c) 2019 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+# Download and unpack googletest at configure time
+configure_file(${CMAKE_CURRENT_LIST_DIR}/CMakeLists.txt.in googletest-download/CMakeLists.txt)
+execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" . RESULT_VARIABLE result1 WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download)
+execute_process(COMMAND ${CMAKE_COMMAND} --build . RESULT_VARIABLE result2 WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download)
+if(result1 OR result2)
+	message(FATAL_ERROR "Preparing googletest failed: ${result1} ${result2}")
+endif()
+
+# Add googletest, defines gtest and gtest_main targets
+add_subdirectory(${CMAKE_CURRENT_BINARY_DIR}/googletest-src ${CMAKE_CURRENT_BINARY_DIR}/googletest-build EXCLUDE_FROM_ALL)
+
+# Remove visibility.h from the compile flags for gtest because of poisoned exit()
+get_target_property(GTEST_COMPILE_FLAGS gtest COMPILE_OPTIONS)
+list(REMOVE_ITEM GTEST_COMPILE_FLAGS "-include")
+list(REMOVE_ITEM GTEST_COMPILE_FLAGS "visibility.h")
+set_target_properties(gtest PROPERTIES COMPILE_OPTIONS "${GTEST_COMPILE_FLAGS}")
+
diff --git a/test/main.cpp b/test/main.cpp
index 3f40e107b0..1eeffca43e 100644
--- a/test/main.cpp
+++ b/test/main.cpp
@@ -2,6 +2,6 @@
 
 int main(int argc, char **argv) {
   testing::InitGoogleTest(&argc, argv);
-  std::cout << "init test \n";
+  std::cout << "Run ECL gtests" << std::endl;
   return RUN_ALL_TESTS();
 }
diff --git a/test/test_EKF_basics.cpp b/test/test_EKF_basics.cpp
new file mode 100644
index 0000000000..76f70d66a5
--- /dev/null
+++ b/test/test_EKF_basics.cpp
@@ -0,0 +1,295 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2019 ECL Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#include <gtest/gtest.h>
+#include <cmath>
+#include "EKF/ekf.h"
+
+class EkfInitializationTest : public ::testing::Test {
+ public:
+
+	Ekf _ekf{};
+
+	// Basics sensors
+	const uint32_t _imu_dt_us{4000};	// 250 Hz	Period between IMU updates
+	const uint32_t _baro_dt_us{12500};	// 80 Hz	Period between barometer updates
+	const uint32_t _mag_dt_us{12500};	// 80 Hz	Period between magnetometer updates
+	const uint32_t _gps_dt_us{200000};	// 5 Hz		Period between GPS updates
+
+	// Flags that control if a sensor is fused
+	bool _fuse_imu{true};
+	bool _fuse_baro{true};
+	bool _fuse_mag{true};
+	bool _fuse_gps{false};	// GPS measurements are expected to not come in from beginning
+
+	// GPS message
+	gps_message _gps_message{};
+
+	uint32_t _update_dt_us{};			// greatest common divider of all basic sensor periods
+	const uint32_t _init_duration_us{2000000};	// 2s	Duration of
+
+	// counter of how many sensor measurement are put into Ekf
+	uint32_t _counter_imu{0};
+	uint32_t _counter_baro{0};
+	uint32_t _counter_mag{0};
+
+	uint32_t _t_us{0};
+
+	// Setup the Ekf with synthetic measurements
+	void SetUp() override
+	{
+
+		_ekf.init(0);
+
+		// setup gps message to reasonable default values
+		_gps_message.time_usec = 0;
+		_gps_message.lat = 473566094;
+		_gps_message.lon = 85190237;
+		_gps_message.alt = 422056;
+		_gps_message.yaw = 0.0f;
+		_gps_message.yaw_offset = 0.0f;
+		_gps_message.fix_type = 3;
+		_gps_message.eph = 0.5f;
+		_gps_message.epv = 0.8f;
+		_gps_message.sacc = 0.2f;
+		_gps_message.vel_m_s = 0.0;
+		_gps_message.vel_ned[0] = 0.0f;
+		_gps_message.vel_ned[1] = 0.0f;
+		_gps_message.vel_ned[2] = 0.0f;
+		_gps_message.vel_ned_valid = 1;
+		_gps_message.nsats = 16;
+		_gps_message.gdop = 0.0f;
+
+		update_with_const_sensors(_init_duration_us);
+
+		// output how many sensor measurement were put into the EKF
+		// std::cout << "Initialized EKF with:" << std::endl;
+		// std::cout << "update_dt_us: " << _update_dt_us << std::endl;
+		// std::cout << "counter_imu:  " << _counter_imu << std::endl
+		// 	  << "counter_baro: " << _counter_baro << std::endl
+		// 	  << "counter_mag:  " << _counter_mag << std::endl;
+	}
+
+	void update_with_const_sensors(uint32_t duration_us,
+			Vector3f ang_vel = Vector3f{0.0f,0.0f,0.0f},
+			Vector3f accel = Vector3f{0.0f,0.0f,-CONSTANTS_ONE_G},
+			Vector3f mag_data = Vector3f{0.2f, 0.0f, 0.4f},
+			float baro_data = 122.2f)
+	{
+		// store start time
+		uint32_t start_time_us = _t_us;
+
+		// compute update time step such that we can update the basic sensor at different rates
+		_update_dt_us = std::__gcd(_imu_dt_us,std::__gcd(_mag_dt_us,std::__gcd(_baro_dt_us,_gps_dt_us)));
+
+		// update EKF with synthetic sensor measurements
+		for( ; _t_us < start_time_us+duration_us; _t_us += _update_dt_us)
+		{
+			// Check which sensors update we should do
+			if(_fuse_imu && !(_t_us %_imu_dt_us))
+			{
+				// push imu data into estimator
+				imuSample imu_sample_new;
+				imu_sample_new.time_us = _t_us;
+				imu_sample_new.delta_ang_dt = _imu_dt_us * 1.e-6f;
+				imu_sample_new.delta_ang = ang_vel * imu_sample_new.delta_ang_dt;
+				imu_sample_new.delta_vel_dt = _imu_dt_us * 1.e-6f;
+				imu_sample_new.delta_vel = accel * imu_sample_new.delta_vel_dt;
+
+				_ekf.setIMUData(imu_sample_new);
+				_counter_imu++;
+			}
+			if(_fuse_baro && !(_t_us % _baro_dt_us))
+			{
+				_ekf.setBaroData(_t_us,baro_data);
+				_counter_baro++;
+			}
+			if(_fuse_mag && !(_t_us % _mag_dt_us))
+			{
+				float mag[3];
+				mag_data.copyTo(mag);
+				_ekf.setMagData(_t_us,mag);
+				_counter_mag++;
+			}
+			if(_fuse_gps && !(_t_us % _gps_dt_us))
+			{
+				_gps_message.time_usec = _t_us;
+				_ekf.setGpsData(_t_us,_gps_message);
+				_counter_mag++;
+			}
+
+			_ekf.update();
+		}
+	}
+
+	// Use this method to clean up any memory, network etc. after each test
+	void TearDown() override
+	{
+
+	}
+};
+
+
+TEST_F(EkfInitializationTest, tiltAlign)
+{
+	// GIVEN: reasonable static sensor data for some duration
+	// THEN: EKF should tilt align
+	EXPECT_EQ(true,_ekf.attitude_valid());
+}
+
+TEST_F(EkfInitializationTest, initialControlMode)
+{
+	// GIVEN: reasonable static sensor data for some duration
+	// THEN: EKF control status should be reasonable
+	filter_control_status_u control_status;
+	_ekf.get_control_mode(&control_status.value);
+
+	EXPECT_EQ(1, (int) control_status.flags.tilt_align);
+	EXPECT_EQ(1, (int) control_status.flags.yaw_align);
+	EXPECT_EQ(0, (int) control_status.flags.gps);
+	EXPECT_EQ(0, (int) control_status.flags.opt_flow);
+	EXPECT_EQ(1, (int) control_status.flags.mag_hdg);
+	EXPECT_EQ(0, (int) control_status.flags.mag_3D);
+	EXPECT_EQ(0, (int) control_status.flags.mag_dec);
+	EXPECT_EQ(0, (int) control_status.flags.in_air);
+	EXPECT_EQ(0, (int) control_status.flags.wind);
+	EXPECT_EQ(1, (int) control_status.flags.baro_hgt);
+	EXPECT_EQ(0, (int) control_status.flags.rng_hgt);
+	EXPECT_EQ(0, (int) control_status.flags.gps_hgt);
+	EXPECT_EQ(0, (int) control_status.flags.ev_pos);
+	EXPECT_EQ(0, (int) control_status.flags.ev_yaw);
+	EXPECT_EQ(0, (int) control_status.flags.ev_hgt);
+	EXPECT_EQ(0, (int) control_status.flags.fuse_beta);
+	EXPECT_EQ(0, (int) control_status.flags.update_mag_states_only);
+	EXPECT_EQ(0, (int) control_status.flags.fixed_wing);
+	EXPECT_EQ(0, (int) control_status.flags.mag_fault);
+	EXPECT_EQ(0, (int) control_status.flags.gnd_effect);
+	EXPECT_EQ(0, (int) control_status.flags.rng_stuck);
+	EXPECT_EQ(0, (int) control_status.flags.gps_yaw);
+	EXPECT_EQ(0, (int) control_status.flags.mag_align_complete);
+	EXPECT_EQ(0, (int) control_status.flags.ev_vel);
+	EXPECT_EQ(0, (int) control_status.flags.synthetic_mag_z);
+}
+
+TEST_F(EkfInitializationTest, convergesToZero)
+{
+	// GIVEN: initialized EKF with default IMU, baro and mag input for 2s
+	// WHEN: Added more defautl sensor measurements
+	update_with_const_sensors(4000000); // for further 4s
+
+	float converged_pos[3];
+	float converged_vel[3];
+	float converged_accel_bias[3];
+	float converged_gyro_bias[3];
+	_ekf.get_position(converged_pos);
+	_ekf.get_velocity(converged_vel);
+	_ekf.get_accel_bias(converged_accel_bias);
+	_ekf.get_gyro_bias(converged_gyro_bias);
+
+	// THEN: EKF should stay or converge to zero
+	for(int i=0; i<3; ++i)
+	{
+		EXPECT_NEAR(0.0f,converged_pos[i],0.001f);
+		EXPECT_NEAR(0.0f,converged_vel[i],0.001f);
+		EXPECT_NEAR(0.0f,converged_accel_bias[i],0.001f);
+		EXPECT_NEAR(0.0f,converged_gyro_bias[i],0.001f);
+	}
+}
+
+TEST_F(EkfInitializationTest, gpsFusion)
+{
+	// GIVEN: initialized EKF with default IMU, baro and mag input for 2s
+	// WHEN: setting GPS measurements for 11s, minimum GPS health time is set to 10 sec
+
+	_fuse_gps = true;
+	update_with_const_sensors(11000000,Vector3f{0.0f,0.0f,0.0f},Vector3f{0.0f,0.0f,-CONSTANTS_ONE_G}); // for further 3s
+
+	// THEN: EKF should fuse GPS, but no other position sensor
+	filter_control_status_u control_status;
+	_ekf.get_control_mode(&control_status.value);
+	EXPECT_EQ(1, (int) control_status.flags.tilt_align);
+	EXPECT_EQ(1, (int) control_status.flags.yaw_align);
+	EXPECT_EQ(1, (int) control_status.flags.gps);
+	EXPECT_EQ(0, (int) control_status.flags.opt_flow);
+	EXPECT_EQ(1, (int) control_status.flags.mag_hdg);
+	EXPECT_EQ(0, (int) control_status.flags.mag_3D);
+	EXPECT_EQ(0, (int) control_status.flags.mag_dec);
+	EXPECT_EQ(0, (int) control_status.flags.in_air);
+	EXPECT_EQ(0, (int) control_status.flags.wind);
+	EXPECT_EQ(1, (int) control_status.flags.baro_hgt);
+	EXPECT_EQ(0, (int) control_status.flags.rng_hgt);
+	EXPECT_EQ(0, (int) control_status.flags.gps_hgt);
+	EXPECT_EQ(0, (int) control_status.flags.ev_pos);
+	EXPECT_EQ(0, (int) control_status.flags.ev_yaw);
+	EXPECT_EQ(0, (int) control_status.flags.ev_hgt);
+	EXPECT_EQ(0, (int) control_status.flags.fuse_beta);
+	EXPECT_EQ(0, (int) control_status.flags.update_mag_states_only);
+	EXPECT_EQ(0, (int) control_status.flags.fixed_wing);
+	EXPECT_EQ(0, (int) control_status.flags.mag_fault);
+	EXPECT_EQ(0, (int) control_status.flags.gnd_effect);
+	EXPECT_EQ(0, (int) control_status.flags.rng_stuck);
+	EXPECT_EQ(0, (int) control_status.flags.gps_yaw);
+	EXPECT_EQ(0, (int) control_status.flags.mag_align_complete);
+	EXPECT_EQ(0, (int) control_status.flags.ev_vel);
+	EXPECT_EQ(0, (int) control_status.flags.synthetic_mag_z);
+}
+
+TEST_F(EkfInitializationTest, accleBiasEstimation)
+{
+	// GIVEN: initialized EKF with default IMU, baro and mag input for 2s
+	// WHEN: Added more sensor measurements with accel bias and gps measurements
+	Vector3f accel_bias = {0.0f,0.0f,0.1f};
+
+	_fuse_gps = true;
+	update_with_const_sensors(10000000,Vector3f{0.0f,0.0f,0.0f},Vector3f{0.0f,0.0f,-CONSTANTS_ONE_G}+accel_bias); // for further 10s
+
+	float converged_pos[3];
+	float converged_vel[3];
+	float converged_accel_bias[3];
+	float converged_gyro_bias[3];
+	_ekf.get_position(converged_pos);
+	_ekf.get_velocity(converged_vel);
+	_ekf.get_accel_bias(converged_accel_bias);
+	_ekf.get_gyro_bias(converged_gyro_bias);
+
+	// THEN: EKF should estimate bias correctelly
+	for(int i=0; i<3; ++i)
+	{
+		EXPECT_NEAR(0.0f,converged_pos[i],0.001f) << "i: " << i;
+		EXPECT_NEAR(0.0f,converged_vel[i],0.001f) << "i: " << i;
+		EXPECT_NEAR(accel_bias(i),converged_accel_bias[i],0.001f) << "i: " << i;
+		EXPECT_NEAR(0.0f,converged_gyro_bias[i],0.001f) << "i: " << i;
+	}
+}
+
+// TODO: Add sampling tests
diff --git a/test/test_example.cpp b/test/test_example.cpp
deleted file mode 100644
index f06369aaca..0000000000
--- a/test/test_example.cpp
+++ /dev/null
@@ -1,7 +0,0 @@
-#include "gtest/gtest.h"
-
-TEST(test_example, sample_test)
-{
-  printf("blabla \n" );
-    EXPECT_EQ(1, 1);
-}