diff --git a/apps/drivers/px4io/px4io.cpp b/apps/drivers/px4io/px4io.cpp
index 8001f1ff6e..f24beaf539 100644
--- a/apps/drivers/px4io/px4io.cpp
+++ b/apps/drivers/px4io/px4io.cpp
@@ -587,9 +587,9 @@ PX4IO::io_send()
 	cmd.f2i_magic = F2I_MAGIC;
 
 	/* set outputs */
-	for (unsigned i = 0; i < _max_actuators; i++)
-		cmd.output_control[i] = _outputs.output[i];
-
+	for (unsigned i = 0; i < _max_actuators; i++) {
+		cmd.output_control[i] = (uint16_t)_outputs.output[i];
+	}
 	/* publish as we send */
 	_outputs.timestamp = hrt_absolute_time();
 	/* XXX needs to be based off post-mix values from the IO side */
diff --git a/apps/systemlib/mixer/mixer_group.cpp b/apps/systemlib/mixer/mixer_group.cpp
index 9aeab1dcc6..25d19f9ade 100644
--- a/apps/systemlib/mixer/mixer_group.cpp
+++ b/apps/systemlib/mixer/mixer_group.cpp
@@ -55,6 +55,8 @@
 
 #define debug(fmt, args...)	do { } while(0)
 //#define debug(fmt, args...)	do { printf("[mixer] " fmt "\n", ##args); } while(0)
+//#include <debug.h>
+//#define debug(fmt, args...)	lib_lowprintf(fmt "\n", ##args)
 
 MixerGroup::MixerGroup(ControlCallback control_cb, uintptr_t cb_handle) :
 	Mixer(control_cb, cb_handle),
diff --git a/apps/systemlib/mixer/mixer_multirotor.cpp b/apps/systemlib/mixer/mixer_multirotor.cpp
index 3dd6dfcf75..cf9debe6c9 100644
--- a/apps/systemlib/mixer/mixer_multirotor.cpp
+++ b/apps/systemlib/mixer/mixer_multirotor.cpp
@@ -56,6 +56,8 @@
 
 #define debug(fmt, args...)	do { } while(0)
 //#define debug(fmt, args...)	do { printf("[mixer] " fmt "\n", ##args); } while(0)
+//#include <debug.h>
+//#define debug(fmt, args...)	lib_lowprintf(fmt "\n", ##args)
 
 #define		CW		(-1.0f)
 #define		CCW		(1.0f)
@@ -213,9 +215,11 @@ unsigned
 MultirotorMixer::mix(float *outputs, unsigned space)
 {
 	float		roll    = get_control(0, 0) * _roll_scale;
+	//lib_lowprintf("roll: %d, get_control0: %d, %d\n", (int)(roll), (int)(get_control(0, 0)), (int)(_roll_scale));
 	float		pitch   = get_control(0, 1) * _pitch_scale;
 	float		yaw     = get_control(0, 2) * _yaw_scale;
 	float		thrust  = get_control(0, 3);
+	//lib_lowprintf("thrust: %d, get_control3: %d\n", (int)(thrust), (int)(get_control(0, 3)));
 	float		max     = 0.0f;
 	float		fixup_scale;
 
@@ -272,7 +276,7 @@ MultirotorMixer::mix(float *outputs, unsigned space)
 		if (outputs[i] < _deadband)
 			outputs[i] = _deadband;
 
-	return 0;
+	return _rotor_count;
 }
 
 void