Added README

spacenav_node/README.md

@@ -0,0 +1,45 @@
+# Spacenav Nodes #
+## spacenav_node
+##### Published topics
+* `spacenav/offset` (geometry_msgs/Vector3)
+>Publishes the linear component of the joystick's position. Approximately normalized to a range of -1 to 1. 
+* `spacenav/rot_offset`(geometry_msgs/Vector3) 
+>Publishes the angular component of the joystick's position. Approximately normalized to a range of -1 to 1. 
+* `spacenav/twist` (geometry_msgs/Twist) 
+>Combines offset and rot_offset into a single message. 
+* `spacenav/joy` (sensor_msgs/Joy) 
+>Outputs the spacenav's six degrees of freedom and its buttons as a joystick message. 
+##### Parameters
+* `zero_when_static`
+>sets values to zero when the spacenav is not moving
+* `static_count_threshold`
+>The number of polls needed to be done before the device is considered "static"
+* `static_trans_deadband`
+>sets the translational deadband
+* `static_rot_deadband`
+>sets the rotational deadband
+* `linear_scale`
+>sets the scale of the linear output
+takes a vector (x, y, z)
+* `angular_scale`
+>sets the scale of the angular output
+takes a vector (x, y, z)
+
+### Running the spacenav_node ###
+
+Running the node the straightforward
+```
+$rosrun spacenav_node spacenav_node
+```
+The node is now publishing to the topics listed above.
+
+Setting the `linear_scale` and `angular_scale` parameters requires a launch file to feed them vector arguements.
+This is an example of how one might do that:
+```
+<launch>
+  <node pkg="spacenav_node" type="spacenav_node" name="$(anon spacenav_node)" output="screen">
+    <rosparam param="linear_scale">[.25, .25, .25]</rosparam>
+    <rosparam param="angular_scale">[.5, .5, .5]</rosparam>
+  </node>
+</launch>
+```