diff --git a/conf/Makefile.sim b/conf/Makefile.sim
index 8097438bdf..b073cba04b 100644
--- a/conf/Makefile.sim
+++ b/conf/Makefile.sim
@@ -56,6 +56,7 @@ CFLAGS += $(INCLUDES)
 CFLAGS += $($(TARGET).CFLAGS)
 CFLAGS += $(LOCAL_CFLAGS)
 CFLAGS += -O2
+CFLAGS += -g
 
 ifneq ($(SIM_TYPE),JSBSIM)
 CFLAGS += -std=gnu99
@@ -63,9 +64,6 @@ endif
 
 LDFLAGS		=	-lm
 
-ifeq ($(SIM_TYPE),BOOZ)
-LDFLAGS		+= $($(TARGET).LDFLAGS)
-endif
 ifeq ($(SIM_TYPE),JSBSIM)
 LDFLAGS		+= $($(TARGET).LDFLAGS)
 endif
@@ -92,11 +90,6 @@ check_jsbsim:
 #	fi
 
 
-ifeq ($(SIM_TYPE),BOOZ)
-$(OBJDIR)/simsitl : $($(TARGET).objs)
-	@echo LD $@
-	$(Q)$(CC) -o $@ $($(TARGET).objs) $(LDFLAGS)
-else
 ifeq ($(SIM_TYPE),JSBSIM)
 $(OBJDIR)/simsitl : $($(TARGET).objs)
 	@echo LD $@
@@ -106,7 +99,6 @@ $(OBJDIR)/simsitl : $($(TARGET).objs) $(SITLCMA) $(SIMSITLML)
 	@echo LD $@
 	$(Q)$(OCAMLC) -g -custom $(CAMLINCLUDES) -o $@ unix.cma str.cma xml-light.cma glibivy-ocaml.cma lib-pprz.cma lablgtk.cma $($(TARGET).objs) $(MYGTKINITCMO) $(SITLCMA) $(SIMSITLML)
 endif
-endif
 
 
 # The id of the A/C is hardcoded in the code (to be improved with dynlink ?)
@@ -140,9 +132,6 @@ $(OBJDIR)/%.o: %.cpp $(OBJDIR)/../Makefile.ac
 	$(Q)test -d $(dir $@) || mkdir -p $(dir $@)
 	$(Q)$(CC) $(CFLAGS) -c -o $@ $<
 
-avr_clean:
-	rm -rf $(OBJDIR)
-
 
 #
 # Dependencies
diff --git a/sw/airborne/arch/sim/mcu_periph/i2c_arch.c b/sw/airborne/arch/sim/mcu_periph/i2c_arch.c
index 34b43d9739..d082af4a24 100644
--- a/sw/airborne/arch/sim/mcu_periph/i2c_arch.c
+++ b/sw/airborne/arch/sim/mcu_periph/i2c_arch.c
@@ -1,9 +1,34 @@
 #include "mcu_periph/i2c.h"
 
-void i2c_hw_init ( void ) {}
-
 bool_t i2c_idle(struct i2c_periph *p __attribute__ ((unused))) { return TRUE; }
 bool_t i2c_submit(struct i2c_periph* p __attribute__ ((unused)), struct i2c_transaction* t __attribute__ ((unused))) { return TRUE;}
 void i2c_event(void) { }
 void i2c2_setbitrate(int bitrate __attribute__ ((unused))) { }
 
+
+#ifdef USE_I2C0
+struct i2c_errors i2c0_errors;
+
+void i2c0_hw_init(void) {
+  i2c0.errors = &i2c0_errors;
+  ZEROS_ERR_COUNTER(i2c0_errors);
+}
+#endif
+
+#ifdef USE_I2C1
+struct i2c_errors i2c1_errors;
+
+void i2c1_hw_init(void) {
+  i2c1.errors = &i2c1_errors;
+  ZEROS_ERR_COUNTER(i2c1_errors);
+}
+#endif
+
+#ifdef USE_I2C2
+struct i2c_errors i2c2_errors;
+
+void i2c2_hw_init(void) {
+  i2c2.errors = &i2c2_errors;
+  ZEROS_ERR_COUNTER(i2c2_errors);
+}
+#endif
diff --git a/sw/airborne/arch/sim/mcu_periph/i2c_arch.h b/sw/airborne/arch/sim/mcu_periph/i2c_arch.h
index 5e3bee40f7..132953028f 100644
--- a/sw/airborne/arch/sim/mcu_periph/i2c_arch.h
+++ b/sw/airborne/arch/sim/mcu_periph/i2c_arch.h
@@ -1,21 +1,36 @@
 #ifndef SIM_MCU_PERIPH_I2C_ARCH_H
 #define SIM_MCU_PERIPH_I2C_ARCH_H
 
+#include "mcu_periph/i2c.h"
+
 #define I2cSendStart() {}
 
-//extern void i2c_hw_init(void);
-#define i2c0_hw_init() {}
-#define i2c1_hw_init() {}
-#define i2c2_hw_init() {}
 
-#define I2c0SendStart() {}
-#define I2c1SendStart() {}
-#define I2c2SendStart() {}
+#ifdef USE_I2C0
 
+extern void i2c0_hw_init(void);
+#define i2c0_ev_irq_handler() {}
+#define i2c0_er_irq_handler() {}
+
+#endif /* USE_I2C0 */
+
+
+#ifdef USE_I2C1
+
+extern void i2c1_hw_init(void);
 #define i2c1_ev_irq_handler() {}
-#define i2c1_er_irq_handler() {};
+#define i2c1_er_irq_handler() {}
 
+#endif /* USE_I2C1 */
+
+
+#ifdef USE_I2C2
+
+extern void i2c2_hw_init(void);
 #define i2c2_ev_irq_handler() {}
-#define i2c2_er_irq_handler() {};
+#define i2c2_er_irq_handler() {}
+
+#endif /* USE_I2C2 */
+
 
 #endif /* SIM_MCU_PERIPH_I2C_ARCH_H */
diff --git a/sw/airborne/firmwares/rotorcraft/telemetry.h b/sw/airborne/firmwares/rotorcraft/telemetry.h
index abd2b233e5..b5adf02c09 100644
--- a/sw/airborne/firmwares/rotorcraft/telemetry.h
+++ b/sw/airborne/firmwares/rotorcraft/telemetry.h
@@ -817,11 +817,15 @@
 #define PERIODIC_SEND_I2C2_ERRORS(_trans, _dev) {}
 #endif
 
+#ifndef SITL
 #define PERIODIC_SEND_I2C_ERRORS(_trans, _dev) { \
     PERIODIC_SEND_I2C0_ERRORS(_trans, _dev);     \
     PERIODIC_SEND_I2C1_ERRORS(_trans, _dev);     \
     PERIODIC_SEND_I2C2_ERRORS(_trans, _dev);     \
 }
+#else
+#define PERIODIC_SEND_I2C_ERRORS(_trans, _dev) {}
+#endif
 
 // FIXME: still used?? or replace by EXTRA_ADC
 #define PERIODIC_SEND_BOOZ2_SONAR(_trans, _dev) {}
diff --git a/sw/simulator/nps/nps_ivy.c b/sw/simulator/nps/nps_ivy.c
index 58409262a0..06dbafbd3c 100644
--- a/sw/simulator/nps/nps_ivy.c
+++ b/sw/simulator/nps/nps_ivy.c
@@ -9,6 +9,7 @@
 #include "nps_autopilot.h"
 #include "nps_fdm.h"
 #include "nps_sensors.h"
+#include "subsystems/ins.h"
 #include "firmwares/rotorcraft/navigation.h"
 
 #include NPS_SENSORS_PARAMS