diff --git a/sw/airborne/booz_ahrs.c b/sw/airborne/booz_ahrs.c
new file mode 100644
index 0000000000..2ed34ca10d
--- /dev/null
+++ b/sw/airborne/booz_ahrs.c
@@ -0,0 +1,19 @@
+#include "booz_ahrs.h"
+
+uint8_t booz_ahrs_status;
+
+float booz_ahrs_phi; 
+float booz_ahrs_theta; 
+float booz_ahrs_psi;
+
+float booz_ahrs_p;
+float booz_ahrs_q;
+float booz_ahrs_r;
+
+float booz_ahrs_bp;
+float booz_ahrs_bq;
+float booz_ahrs_br;
+
+float booz_ahrs_measure_phi;
+float booz_ahrs_measure_theta;
+float booz_ahrs_measure_psi;
diff --git a/sw/airborne/booz_nav_hover.c b/sw/airborne/booz_nav_hover.c
new file mode 100644
index 0000000000..1a6f401119
--- /dev/null
+++ b/sw/airborne/booz_nav_hover.c
@@ -0,0 +1,157 @@
+#include "booz_nav.h"
+
+#include <math.h>
+
+#include "booz_estimator.h"
+#include "booz_control.h"
+#include "radio_control.h"
+
+#ifndef DISABLE_NAV
+float booz_nav_hover_x_sp;
+float booz_nav_hover_y_sp;
+float booz_nav_hover_z_sp;
+float booz_nav_hover_psi_sp;
+
+float booz_nav_hover_h_max_err;
+float booz_nav_hover_h_pgain;
+float booz_nav_hover_h_dgain;
+float booz_nav_hover_v_max_err;
+float booz_nav_hover_v_pgain;
+float booz_nav_hover_v_dgain;
+
+float booz_nav_hover_phi_command;
+float booz_nav_hover_theta_command;
+float booz_nav_hover_power_command;
+
+#define BOOZ_NAV_HOVER_H_MAX_ERR 10.
+/* rad / m */
+#define BOOZ_NAV_HOVER_H_PGAIN (RadOfDeg(20.) / BOOZ_NAV_HOVER_H_MAX_ERR)
+/* rad / (ms-1) */
+#define BOOZ_NAV_HOVER_H_DGAIN (RadOfDeg(5.))
+
+#define BOOZ_NAV_HOVER_MAX_PHI_COMMAND   RadOfDeg(30.)
+#define BOOZ_NAV_HOVER_MAX_THETA_COMMAND RadOfDeg(30.)
+
+#define BOOZ_NAV_HOVER_V_MAX_ERR 10.
+#define BOOZ_NAV_HOVER_V_PGAIN 0.12
+#define BOOZ_NAV_HOVER_V_DGAIN 0.15
+#define BOOZ_NAV_HOVER_V_HOVER_POWER 0.65
+
+static void booz_nav_hover_vertical_loop_run(void);
+static void booz_nav_hover_horizontal_loop_run(void);
+#endif
+
+
+void booz_nav_hover_init(void) {
+#ifndef DISABLE_NAV
+
+  booz_nav_hover_x_sp = 0.;
+  booz_nav_hover_y_sp = 0.;
+  booz_nav_hover_z_sp = 0.;
+  booz_nav_hover_psi_sp = 0.;
+
+  booz_nav_hover_h_max_err =  BOOZ_NAV_HOVER_H_MAX_ERR;
+  booz_nav_hover_h_pgain = BOOZ_NAV_HOVER_H_PGAIN;
+  booz_nav_hover_h_dgain = BOOZ_NAV_HOVER_H_DGAIN;
+  booz_nav_hover_v_max_err = BOOZ_NAV_HOVER_V_MAX_ERR;
+  booz_nav_hover_v_pgain = BOOZ_NAV_HOVER_V_PGAIN;
+  booz_nav_hover_v_dgain = BOOZ_NAV_HOVER_V_DGAIN;
+
+  booz_nav_hover_phi_command = 0.;
+  booz_nav_hover_theta_command = 0.;
+  booz_nav_hover_power_command = 0.;
+
+#endif
+}
+
+void booz_nav_hover_run(void) {
+#ifndef DISABLE_NAV
+  booz_nav_hover_vertical_loop_run();
+  booz_nav_hover_horizontal_loop_run();
+#endif
+}
+
+#define STICK_ABSOLUTE_POS   0
+#define STICK_ABSOLUTE_SPEED 1
+#define STICK_RELATIVE_SPEED 2
+#define STICK_MODE STICK_RELATIVE_SPEED
+#define DT_READ_SETPOINTS 0.004
+void booz_nav_hover_read_setpoints_from_rc(void) {
+#ifndef DISABLE_NAV
+  booz_nav_hover_z_sp   = -1. - 10. / MAX_PPRZ * (float)rc_values[RADIO_THROTTLE];
+  booz_nav_hover_psi_sp = -RadOfDeg(30.) / MAX_PPRZ * (float)rc_values[RADIO_YAW];
+#if defined STICK_MODE && STICK_MODE == STICK_ABSOLUTE_POS
+  booz_nav_horizontal_x_sp = -20. / MAX_PPRZ * (float)rc_values[RADIO_PITCH]; /* +/- 20m */
+  booz_nav_horizontal_y_sp = -20. / MAX_PPRZ * (float)rc_values[RADIO_ROLL];  /* warning RC roll negativ to the right !! +/- 20m */
+  booz_nav_horizontal_u_sp = 0.;
+  booz_nav_horizontal_v_sp = 0.;
+#elif defined STICK_MODE && STICK_MODE == STICK_ABSOLUTE_SPEED
+  booz_nav_horizontal_x_sp += -5. * DT_READ_SETPOINTS / MAX_PPRZ * (float)rc_values[RADIO_PITCH]; /* +/-5 m/s */
+  booz_nav_horizontal_y_sp +=  5. * DT_READ_SETPOINTS / MAX_PPRZ * (float)rc_values[RADIO_ROLL];  /* +/-5 m/s */
+  booz_nav_horizontal_u_sp = 0.;
+  booz_nav_horizontal_v_sp = 0.;
+#elif defined STICK_MODE && STICK_MODE == STICK_RELATIVE_SPEED
+  float booz_nav_hover_dx_bod = -5. / MAX_PPRZ * (float)rc_values[RADIO_PITCH];
+  float booz_nav_hover_dy_bod = -5. / MAX_PPRZ * (float)rc_values[RADIO_ROLL]; /* warning RC roll negativ to the right !! +/- 5m/s */
+  /* convert vector to earth frame ( use transpose of DCM )  */
+  float booz_nav_hover_dx_earth = booz_nav_hover_dx_bod * booz_estimator_dcm[AXIS_X][AXIS_X] +
+                                 booz_nav_hover_dy_bod * booz_estimator_dcm[AXIS_Y][AXIS_X];
+  float booz_nav_hover_dy_earth = booz_nav_hover_dx_bod  * booz_estimator_dcm[AXIS_X][AXIS_Y] +
+                                 booz_nav_hover_dx_bod * booz_estimator_dcm[AXIS_Y][AXIS_Y];
+  booz_nav_hover_x_sp += (booz_nav_hover_dx_earth * DT_READ_SETPOINTS);
+  booz_nav_hover_y_sp += (booz_nav_hover_dy_earth * DT_READ_SETPOINTS);
+#endif /* STICK_MODE  */
+#endif /* DISABLE_NAV */
+}
+
+
+
+#ifndef DISABLE_NAV
+
+/* fisrt a vertical loop */ 
+static void booz_nav_hover_vertical_loop_run(void) {
+  float vertical_err = booz_estimator_z - booz_nav_hover_z_sp;
+  Bound(vertical_err, -booz_nav_hover_v_max_err, booz_nav_hover_v_max_err);
+  float bank_coef = 1. / fabs(cos(booz_estimator_phi)*cos(booz_estimator_theta));
+  float adjusted_hover_power  = BOOZ_NAV_HOVER_V_HOVER_POWER * bank_coef;
+  //  printf("hover power command %f %f\n", bank_coef, adjusted_hover_power);
+  booz_nav_hover_power_command = adjusted_hover_power +
+                              /* BOOZ_NAV_HOVER_V_HOVER_POWER +  */
+                                 booz_nav_hover_v_pgain * vertical_err +
+                                 booz_nav_hover_v_dgain * booz_estimator_vz;
+
+  Bound(booz_nav_hover_power_command, 0., 1.);
+}
+
+/* now a horizontal hovering loop */
+static void booz_nav_hover_horizontal_loop_run(void) {
+  
+  /* get a position error vector              */
+  float x_error = booz_estimator_x - booz_nav_hover_x_sp;
+  float y_error = booz_estimator_y - booz_nav_hover_y_sp;
+  //  printf("earth pos error %f %f\n", x_error, y_error); 
+  /* get norm and unit position error vector  */  
+  float norm_error = sqrt(x_error*x_error+ y_error*y_error);
+  float unit_x_error = x_error / norm_error;
+  float unit_y_error = y_error / norm_error;
+  //  printf("earth pos error %f %f %f\n", unit_x_error, unit_y_error, norm_error); 
+  /* bound the error in amplitude             */
+  Bound(norm_error, 0., booz_nav_hover_h_max_err);
+  /* convert unit error vector to body frame       */
+  float x_unit_err_body = unit_x_error * booz_estimator_dcm[AXIS_X][AXIS_X] +
+                          unit_y_error * booz_estimator_dcm[AXIS_X][AXIS_Y];
+  float y_unit_err_body = unit_x_error * booz_estimator_dcm[AXIS_Y][AXIS_X] +
+                          unit_y_error * booz_estimator_dcm[AXIS_Y][AXIS_Y];
+  //  printf("body  pos error %f %f\n", x_unit_err_body, y_unit_err_body); 
+  /* */
+
+  booz_nav_hover_phi_command   =  - booz_nav_hover_h_pgain * y_unit_err_body * norm_error +
+                                  - booz_nav_hover_h_dgain *  booz_estimator_v;
+  booz_nav_hover_theta_command =    booz_nav_hover_h_pgain * x_unit_err_body * norm_error +
+                                    booz_nav_hover_h_dgain *  booz_estimator_u;
+  
+  Bound(booz_nav_hover_phi_command, -BOOZ_NAV_HOVER_MAX_PHI_COMMAND, BOOZ_NAV_HOVER_MAX_PHI_COMMAND);
+  Bound(booz_nav_hover_theta_command, -BOOZ_NAV_HOVER_MAX_THETA_COMMAND, BOOZ_NAV_HOVER_MAX_THETA_COMMAND);
+
+}
+#endif
diff --git a/sw/airborne/booz_nav_hover.h b/sw/airborne/booz_nav_hover.h
new file mode 100644
index 0000000000..83fefae5e6
--- /dev/null
+++ b/sw/airborne/booz_nav_hover.h
@@ -0,0 +1,28 @@
+#ifndef BOOZ_NAV_HOVER_H
+#define BOOZ_NAV_HOVER_H
+
+
+#ifndef DISABLE_NAV
+extern float booz_nav_hover_x_sp;
+extern float booz_nav_hover_y_sp;
+extern float booz_nav_hover_z_sp;
+extern float booz_nav_hover_psi_sp;
+
+extern float booz_nav_hover_h_max_err;
+extern float booz_nav_hover_h_pgain;
+extern float booz_nav_hover_h_dgain;
+extern float booz_nav_hover_v_max_err;
+extern float booz_nav_hover_v_pgain;
+extern float booz_nav_hover_v_dgain;
+
+extern float booz_nav_hover_phi_command;
+extern float booz_nav_hover_theta_command;
+extern float booz_nav_hover_power_command;
+#endif
+
+extern void booz_nav_hover_init(void);
+extern void booz_nav_hover_run(void);
+extern void booz_nav_hover_read_setpoints_from_rc(void);
+
+
+#endif /* BOOZ_NAV_HOVER_H */
diff --git a/sw/airborne/sim/micromag_hw.c b/sw/airborne/sim/micromag_hw.c
new file mode 100644
index 0000000000..c0ac397185
--- /dev/null
+++ b/sw/airborne/sim/micromag_hw.c
@@ -0,0 +1,12 @@
+#include "micromag.h"
+
+#include "../../simulator/booz_sensors_model.h"
+
+void micromag_hw_init( void ) {}
+
+
+void micromag_read( void ) {
+  micromag_values[0] =  bsm.mag->ve[AXIS_X];
+  micromag_values[1] =  bsm.mag->ve[AXIS_Y];
+  micromag_values[2] =  bsm.mag->ve[AXIS_Z];
+}
diff --git a/sw/airborne/sim/micromag_hw.h b/sw/airborne/sim/micromag_hw.h
new file mode 100644
index 0000000000..2a278e9612
--- /dev/null
+++ b/sw/airborne/sim/micromag_hw.h
@@ -0,0 +1,8 @@
+#ifndef MICROMAG_HW_H
+#define MICROMAG_HW_H
+
+
+
+
+
+#endif /* MICROMAG_HW_H */