pybricks.common.Accelerometer: Use mm/s/s units.

Fixes #94

For Move Hub, this is a breaking change since Move Hub IMU support
was already released. For the other hubs, the IMU API has not been
released yet, so we can do this silently.

doc/main/hubs/movehub.rst

@@ -27,6 +27,10 @@ Move Hub
 
     .. automethod:: pybricks.hubs::MoveHub.imu.acceleration
 
+        .. versionchanged:: 3.2
+
+            Changed acceleration units from m/s/s to mm/s/s.
+
     .. rubric:: Using the battery
 
     .. automethod:: pybricks.hubs::MoveHub.battery.voltage

doc/main/signaltypes.rst

@@ -118,22 +118,13 @@ linear acceleration: mm/s/s
 --------------------------------
 
 Linear acceleration describes how fast the speed changes. This is expressed as
-the change of the millimeters per second, during one second (deg/s/s).
+the change of the millimeters per second, during one second (mm/s/s).
 This is also commonly written as  :math:`mm/s^2`.
 
 For example, you can adjust the acceleration setting of a
 :class:`DriveBase <.robotics.DriveBase>` to change how
 smoothly or how quickly it reaches the constant speed set point.
 
-.. _linacceleration_m:
-
-linear acceleration: m/s/s
---------------------------------
-
-As above, but expressed in meters per second squared: :math:`m/s^2`.
-This is a more practical unit for large values such as those given by an
-accelerometer.
-
 Approximate and relative units
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

src/pybricks/_common.py

@@ -761,7 +761,7 @@ def acceleration(self):
         """Gets the acceleration of the device.
 
         Returns:
-            tuple of :ref:`linacceleration_m`: Acceleration along all three
+            tuple of :ref:`linacceleration`: Acceleration along all three
             axes.
         """
         pass
@@ -807,7 +807,7 @@ def acceleration(self, axis=None):
             axis (Axis): Axis along which the acceleration is
                          measured.
         Returns:
-            :ref:`linacceleration_m`: Acceleration along the
+            :ref:`linacceleration`: Acceleration along the
             specified axis. If you specify no axis, this returns a vector
             of accelerations along all axes.
         """