[ADD] IoT: New doc about how to connect a scale using the IoT box.

content/applications/productivity/iot/devices.rst

@@ -9,4 +9,5 @@ Devices
    devices/measurement_tool
    devices/camera
    devices/footswitch
-   devices/printer
+   devices/printer
+   devices/scale

content/applications/productivity/iot/devices/scale.rst

@@ -0,0 +1,55 @@
+===============
+Connect a Scale
+===============
+
+When using your **IoT Box** in Odoo, you could need to use a scale. Doing so is easy and convenient
+as it can be done in a few steps. Then, you can use it in your **Point of Sale app** to weigh your
+products, which is helpful if their price are based on it.
+
+Connection
+==========
+
+To link the scale to the **IoT Box**, connect them with a cable.
+
+.. note::
+   In some cases, a serial to USB adapter may be needed.
+
+If your scale is `compatibale with Odoo IoT Box <https://www.odoo.com/page/iot-hardware>`_, there
+is no need to set up anything because it will be automatically detected as soon as it is connected.
+
+.. image:: scale/iot-choice.png
+   :align: center
+   :alt: IOT box auto detection.
+
+You may need to restart the box and download your scales’ drivers from the box in some cases. To do
+so, go to the *IoT Box Home Page* and click on *drivers list*. Then, click on load drivers.
+
+.. image:: scale/driver-list.png
+   :align: center
+   :alt: View of the IoT box settings and driver list.
+
+Use a Scale in Point of Sale
+============================
+
+To use the scale in your *Point of Sale* app, go to :menuselection:`Point of Sale --> Configuration
+--> Point of Sale`, open the one you want to configure, then click on *Edit* and enable the *IoT
+Box* feature.
+
+.. image:: scale/iot-box-pos.png
+   :align: center
+   :alt: View of the IoT box feature inside of the PoS settings.
+
+Now, choose the *IoT Box* in the dropdown menu and check the *Electronic Scale* option. Then, you
+hit save.
+
+.. image:: scale/electronic-scale-feature.png
+   :align: center
+   :alt: List of the external tools that can be used with PoS and the IoT box.
+
+The scale is now available in all your *PoS* sessions. Then, if a product has a price per weight
+set, clicking on it on the *PoS* screen opens the scale screen, where the cashier can weigh the
+product and add the correct price to the cart.
+
+.. image:: scale/scale-view.png
+   :align: center
+   :alt: Electronic Scale dashboard view when no items are being weighed.