diff --git a/Tools/posix_apps.py b/Tools/posix_apps.py
index 00e11fcbbb..1dfca71e27 100755
--- a/Tools/posix_apps.py
+++ b/Tools/posix_apps.py
@@ -48,6 +48,7 @@ print """
 
 #include <px4_tasks.h>
 #include <px4_posix.h>
+#include <stdlib.h>
 
 using namespace std;
 
@@ -64,6 +65,7 @@ static int list_tasks_main(int argc, char *argv[]);
 static int list_files_main(int argc, char *argv[]);
 static int list_devices_main(int argc, char *argv[]);
 static int list_topics_main(int argc, char *argv[]);
+static int sleep_main(int argc, char *argv[]);
 }
 
 
@@ -81,6 +83,7 @@ print '\tapps["list_tasks"] = list_tasks_main;'
 print '\tapps["list_files"] = list_files_main;'
 print '\tapps["list_devices"] = list_devices_main;'
 print '\tapps["list_topics"] = list_topics_main;'
+print '\tapps["sleep"] = sleep_main;'
 print """
 	return apps;
 }
@@ -122,5 +125,14 @@ static int list_files_main(int argc, char *argv[])
 	px4_show_files();
 	return 0;
 }
+static int sleep_main(int argc, char *argv[])
+{
+	if (argc != 2) {
+		cout << "Usage: sleep <seconds>" << endl;
+		return 1;
+	}
+	sleep(atoi(argv[1]));
+	return 0;
+}
 """
 
diff --git a/makefiles/posix/config_posix_default.mk b/makefiles/posix/config_posix_default.mk
index 30dada7bbd..5f1d80bdea 100644
--- a/makefiles/posix/config_posix_default.mk
+++ b/makefiles/posix/config_posix_default.mk
@@ -7,6 +7,7 @@
 #
 MODULES		+= drivers/device
 MODULES		+= drivers/blinkm
+MODULES		+= drivers/buzzer
 MODULES		+= drivers/hil
 MODULES		+= drivers/rgbled
 MODULES		+= drivers/led
diff --git a/posix-configs/posixtest/init/rc.S b/posix-configs/posixtest/init/rc.S
index 896062639e..93e6c69d01 100644
--- a/posix-configs/posixtest/init/rc.S
+++ b/posix-configs/posixtest/init/rc.S
@@ -1,5 +1,6 @@
 uorb start
 simulator start -s
+sleep 2
 barosim start
 adcsim start
 accelsim start
diff --git a/src/drivers/device/i2c_posix.cpp b/src/drivers/device/i2c_posix.cpp
index ddf7a0db4c..aa031d9e42 100644
--- a/src/drivers/device/i2c_posix.cpp
+++ b/src/drivers/device/i2c_posix.cpp
@@ -69,7 +69,7 @@ I2C::I2C(const char *name,
 	_address(address),
 	_fd(-1)
 {
-	warnx("I2C::I2C name = %s devname = %s", name, devname);
+	//warnx("I2C::I2C name = %s devname = %s", name, devname);
 	// fill in _device_id fields for a I2C device
 	_device_id.devid_s.bus_type = DeviceBusType_I2C;
 	_device_id.devid_s.bus = bus;
diff --git a/src/modules/sensors/sensors.cpp b/src/modules/sensors/sensors.cpp
index bc1ae89906..0be31046b1 100644
--- a/src/modules/sensors/sensors.cpp
+++ b/src/modules/sensors/sensors.cpp
@@ -868,7 +868,7 @@ Sensors::parameters_update()
 	barofd = px4_open(BARO0_DEVICE_PATH, 0);
 
 	if (barofd < 0) {
-		warnx("ERROR: no barometer foundon %s", BARO0_DEVICE_PATH);
+		warnx("ERROR: no barometer found on %s", BARO0_DEVICE_PATH);
 		return ERROR;
 
 	} else {
diff --git a/src/platforms/posix/drivers/accelsim/accelsim.cpp b/src/platforms/posix/drivers/accelsim/accelsim.cpp
index 994b1bfb9b..174c522383 100644
--- a/src/platforms/posix/drivers/accelsim/accelsim.cpp
+++ b/src/platforms/posix/drivers/accelsim/accelsim.cpp
@@ -774,7 +774,7 @@ ACCELSIM::mag_ioctl(device::file_t *filp, int cmd, unsigned long arg)
 					unsigned period = 1000000 / arg;
 
 					/* check against maximum sane rate (1ms) */
-					if (period < 1000)
+					if (period < 10000)
 						return -EINVAL;
 
 					/* update interval for next measurement */
@@ -961,11 +961,10 @@ ACCELSIM::start()
 	//PX4_INFO("ACCELSIM::start accel %u", _call_accel_interval);
 	hrt_call_every(&_accel_call, 1000, _call_accel_interval, (hrt_callout)&ACCELSIM::measure_trampoline, this);
 
-
-	// There is a race here where SENSORIOCSPOLLRATE on the accel starts polling of mag but mag period is set to 0
+	// There is a race here where SENSORIOCSPOLLRATE on the accel starts polling of mag but _call_mag_interval is 0
 	if (_call_mag_interval == 0) {
-		PX4_ERR("_call_mag_interval uninitilized - would have set period delay of 0");
-		_call_mag_interval = 1000;
+		//PX4_INFO("_call_mag_interval uninitilized - would have set period delay of 0");
+		_call_mag_interval = 10000; // Max 100Hz
 	}
 
 	//PX4_INFO("ACCELSIM::start mag %u", _call_mag_interval);
diff --git a/src/platforms/posix/drivers/gyrosim/gyrosim.cpp b/src/platforms/posix/drivers/gyrosim/gyrosim.cpp
index 54e448cabb..40d8f71c1b 100644
--- a/src/platforms/posix/drivers/gyrosim/gyrosim.cpp
+++ b/src/platforms/posix/drivers/gyrosim/gyrosim.cpp
@@ -466,6 +466,9 @@ GYROSIM::GYROSIM(const char *path_accel, const char *path_gyro, enum Rotation ro
 	// disable debug() calls
 	_debug_enabled = false;
 
+	// Don't publish until initialized
+	_pub_blocked = true;
+
 	_device_id.devid_s.devtype = DRV_ACC_DEVTYPE_GYROSIM;
 
 	/* Prime _gyro with parents devid. */
@@ -588,6 +591,9 @@ GYROSIM::init()
 	if (_accel_topic == nullptr) {
 		PX4_WARN("ADVERT FAIL");
 	}
+	else {
+		_pub_blocked = false;
+	}
 
 
 	/* advertise sensor topic, measure manually to initialize valid report */