:orphan:

.. include:: variables.rst
.. include:: special.rst


.. _bluetoothformulas:

Bluetooth Range Calculations
============================

Our assumptions for the two examples are:

.. list-table::
   :widths: 10 70 10 10
   :header-rows: 1
   :align: center

   * - Abbreviation
     - Description
     - meters
     - feet
   * - OL
     - Overall Length of tow vehicle (bumper to bumper)
     - 6
     - 20
   * - RVL
     - Overall Length of RV (tongue to bumper)
     - 7
     - 24
   * - T2FS
     - Tongue to front storage (pass through)
     - 1.5
     - 5 
   * - FB2FS
     - Front Bumper to Front Seat of tow vehicle
     - 2
     - 6
   * - BLE 
     - Operating Range of Bluetooth LE Radio (Class 1.5)
     - 30
     - 100
 

.. attention::

   To improve the reliability of the connection we take the theoretical range (from the Chart) for a :ref:`class 1.5 device<bluetoothrangeexpectations>` and divide it by a factor of four. 
   This will effectively take our range from the theoretical maximum of 30 m (100ft) to 7.5m (25ft).

Tow Vehicle
-----------


.. figure:: /images/truck.gmc.1500.measurements.png
   :align: center  

   **Tow Vehicle** - GMC 1500 Pickup Truck


Travel Trailer
--------------

.. figure:: /images/rv.lance.1995.png
   :align: center  

   **Travel Trailer** - Lance 1995



Example 1 - Worst Case - |MODULENAME| module at Rear of RV
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

In this example we will mount the |MODULENAME| Pro module at the rear of the trailer - absolute worst case

.. math::

   ≥ 0 = (BLE /Margin) - ((OL – FB2FS) + (RVL))


**Metric**

:red:`-3.5 m`   = (30 m  / 4)   - ((6 m - 2 m) + 7 m)

**Imperial**

:red:`-13.0 ft`  = (100 ft / 4) - ((20 ft - 6 ft) + 24 ft) 

Example 2 - Best Case - |MODULENAME| module in Front Pass Through
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

In this example we will mount the |MODULENAME| Pro module in the front pass through storage of the RV


.. math::

   ≥ 0 = (BLE /Margin) - ((OL – FB2FS) + (T2FS))


**Metric**

:green:`+2.0 m` = (30 m   / 4) - ((6 m  - 2 m) + 1.5 m) 

**Imperial**

:green:`+6.0 ft` = (100 ft / 4) - ((20 ft - 6 ft) + 5 ft) 
  

.. admonition::  Bottom Line

   If the result of the calculation is a negative number, you may experience |ble| connection issues between your mobile device and the |MODULENAME| module.