ekf_localization_node type error for topic imu0
I'm setting up a ekf_localization_node and feeding it with a Sensor_msgs/Imu message (from a Razor), but getting this error,
ERROR 1432289505.280310120: ERROR reading sensor update config: type error for topic imu0 (type: 0, expected: 7) WARN 1432289505.280386707: Warning: imu is listed as an input topic, but all its update variables are false
despite having,
$rostopic type imu
sensor_msgs/Imu
any ideas what's wrong with this? What do the types 0 and 7 mean here, and is there a way to look them up?
Further details, here's my launch,
<launch>
<node pkg="robot_localization" type="ekf_localization_node" output="screen" name="ekf_localization_node">
<param name="odom0" value="odometry/gps"/>
<param name="imu0" value="imu"/>
<rosparam param="odom0_config">[true, true, false,
false, false, false,
false, false, false,
false, false, false,
false, false, false]</rosparam>
<rosparam param="imu0">[false, false, false,
false false, true,
false, false, false,
false, false, true,
true, false, false]</rosparam>
<param name="odom0_differential" value="false"/>
</node>
</launch>
I still get the same error message about type 0 vs type 7 if I comment out all references to imu in the launch params, suggesting something may be wrong with the way imu is specified in the launch ?