add units to msgs

msgs.rst

@@ -4,99 +4,103 @@ msgs
 Accelerometer
 *************
 
+.. image:: /images/accelerometer.png
+
 Units are in m/s :sup:`2`
 
-.. image:: /images/accelerometer.png
+Note that gravity is measured by an accelerometer.
+When standing, the robot will measure 9.8 m/s :sup:`2` POSITIVE in the z-direction, since its 
+receiving an acceleration upwards from the floor when compared to a freefall state.
 
 .. code-block:: cpp
 
-    float32 x
-    float32 y
-    float32 z
+    float32 x  // m/s/s
+    float32 y  // m/s/s
+    float32 z  // m/s/s
 
 Angle
 *****
 
-Units are in rad
-
 .. image:: /images/angle.png
 
+Units are in rad.
+
 .. code-block:: cpp
 
-    float32 x
-    float32 y
+    float32 x  // rad
+    float32 y  // rad
 
 Battery
 *******
 
 .. code-block:: cpp
 
-    float32 charge
+    float32 charge  // 0% - 100%
     float32 status
-    float32 current
-    float32 temperature
+    float32 current  // in A, negative for discharge, positive for charge
+    float32 temperature  // Celcius (°C)
 
 Buttons
 *******
 
 .. code-block:: cpp
 
-    bool chest
-    bool l_foot_bumper_left
-    bool l_foot_bumper_right
-    bool r_foot_bumper_left
-    bool r_foot_bumper_right
+    bool chest  // true if being pressed
+    bool l_foot_bumper_left  // true if being pressed
+    bool l_foot_bumper_right  // true if being pressed
+    bool r_foot_bumper_left  // true if being pressed
+    bool r_foot_bumper_right  // true if being pressed
 
 FSR
 ***
 
 .. code-block:: cpp
 
-    float32 l_foot_front_left
-    float32 l_foot_front_right
-    float32 l_foot_back_left
-    float32 l_foot_back_right
-    float32 r_foot_front_left
-    float32 r_foot_front_right
-    float32 r_foot_back_left
-    float32 r_foot_back_right
+    float32 l_foot_front_left  // kg
+    float32 l_foot_front_right  // kg
+    float32 l_foot_back_left  // kg
+    float32 l_foot_back_right  // kg
+    float32 r_foot_front_left  // kg
+    float32 r_foot_front_right  // kg
+    float32 r_foot_back_left  // kg
+    float32 r_foot_back_right  // kg
 
 Gyroscope
 *********
 
-Units are in rad/s
-
 .. image:: /images/gyroscope.png
 
+Units are in rad/s.
+
 .. code-block:: cpp
 
-    float32 x
-    float32 y
-    float32 z
+    float32 x  // rad/s
+    float32 y  // rad/s
+    float32 z  // rad/s
 
 Joints
 ******
 
 .. code-block:: cpp
 
-    float32[25] angles
-    float32[25] stiffnesses
-    float32[25] temperatures
-    float32[25] currents
+    float32[25] angles  // rad
+    float32[25] stiffnesses  // 0.0 - 1.0
+    float32[25] temperatures  // Celcius (°C)
+    float32[25] currents  // Amperes (A)
 
 Sonar
 *****
 
 .. code-block:: cpp
 
-    float32 left
-    float32 right
+    float32 left  // m
+    float32 right  // m
 
 Touch
 *****
 
 .. code-block:: cpp
 
-    bool head_front
-    bool head_middle
-    bool head_rear
+    bool head_front  // true if being touched
+    bool head_middle  // true if being touched
+    bool head_rear  // true if being touched