README: update ROS API

README.md

@@ -8,20 +8,25 @@
 
     Target velocity of the Rover. Only linear.x (m/s) and angular.z (r/s) are used.
 
-* **`servoX/command`** ([std_msgs/Int16])
+* **`servoX/angle`** ([std_msgs/Int16])
 
-    Angular position (in degrees) of servo X
+    Angular position (in degrees) of servo X. Angle to pulse duration relationship is configurable through `params.h` file
+
+* **`servoX/pwm`** ([std_msgs/UInt16MultiArray])
+
+    Pulse duration and period (in us). The values are passed through `data` array. Publishing to pwm topic overrides angle value and vice versa
 
 ### Published topics
 
 * **`odom`** ([geometry_msgs/Twist])
 
     Current linear and angular velocities estimated from encoder readings
 
-* **`battery`** ([sensor_msgs/BatteryState])
+* **`battery`** ([std_msgs/Float32])
 
     Current battery voltage reading
 
 [geometry_msgs/Twist]: http://docs.ros.org/api/geometry_msgs/html/msg/Twist.html
 [std_msgs/Int16]: http://docs.ros.org/melodic/api/std_msgs/html/msg/Int16.html
-[sensor_msgs/BatteryState]: http://docs.ros.org/melodic/api/sensor_msgs/html/msg/BatteryState.html
+[std_msgs/Float32]: http://docs.ros.org/api/std_msgs/html/msg/Float32.html
+[std_msgs/UInt16MultiArray]: http://docs.ros.org/api/std_msgs/html/msg/UInt16MultiArray.html