def on_acceleration_change(obj=nil, &block)
	  @on_acceleration_change_obj = obj
      @on_acceleration_change = Proc.new { |device, obj_ptr, ind, acc|
		yield self, axes[ind], acc, object_for(obj_ptr)
	}
      Klass.set_OnAccelerationChange_Handler(@handle, @on_acceleration_change, pointer_for(obj))
    end
def on_acceleration_change(obj=nil, &block)
	  @on_acceleration_change_obj = obj
      @on_acceleration_change = Proc.new { |device, obj_ptr, ind, acc|
		yield self, axes[ind], acc, object_for(obj_ptr)
	}
      Klass.set_OnAccelerationChange_Handler(@handle, @on_acceleration_change, pointer_for(obj))
    end
Sets an acceleration change handler callback function. This is called when the acceleration of an axis changes by more than the set sensitivity.

 @param [String] obj Object to pass to the callback function. This is optional.
 @param [Proc] Block When the callback is executed, the device and object are yielded to this block.
 @example
     acc.on_acceleration_change do |device, axis, acceleration, obj|
       puts "Axis #{axis.index}'s acceleration changed to #{acceleration}"
     end
 As this runs in it's own thread, be sure that all errors are properly handled or the thread will halt and not fire any more.
 @return [Boolean] returns true or raises an error