Add Absolute Encoder and Wind-Vane-Absolute-Encoder Docs

common/source/docs/common-absolute-encoder.rst

@@ -0,0 +1,31 @@
+.. _common-absolute-encoder:
+[copywiki destination="rover"]
+
+=====
+Absolute Encoder
+=====
+
+This article describes how to attach an absolute encoder so that your vehicle can sense angular position. This is used most commonly 
+for :ref:`wind-vane sensors <wind-vane>` for sailing rovers.
+
+Currently, only AS5048B Encoders are supported.
+
+AutoPilot connection
+--------------------
+Connect the encoder to the autopilot's I2C Port using standard connections.
+
+Autopilot Configuration
+-----------------------
+
+Connect to the autopilot with a ground station and set these parameters and then reload the parameters.
+
+- :ref:`AENC_TYPE <AENC_TYPE>` = 1 (Enable)
+
+After reloading parameters, set the following parameters:
+
+- :ref:`AENC_BUS <AENC_BUS>` - set this to the serial bus ID for the I2C bus you've connected to.
+- :ref:`AENC_ADDR <AENC_ADDR>` - set this to the I2C Address of your sensor (defaults to 64 for AS5048B).
+- :ref:`AENC_OFFS <AENC_OFFS>` - set this to apply an offset in degrees to the zero position.
+- :ref:`AENC_DIR <AENC_DIR>` - set this to -1 if you need to reverse the direction of rotation for the encoder.
+
+

rover/source/docs/wind-vane-absolute-encoder.rst

@@ -0,0 +1,17 @@
+.. _wind-vane-absolute-encoder:
+
+=======================
+Absolute Encoder Wind Vane
+=======================
+
+An absolute encoder can be configured as the wind-vane direction source. In order to use this option, you must first configure
+the absolute encoder as described in the :ref:`Absolute Encoder library <common-absolute-encoder>` documentation.
+
+To select the absolute encoder as the win-dvane direction source, set :ref:`WNDVN_TYPE <WNDVN_TYPE>` = 4. Then, select the absolute 
+encoder instance via the :ref:`WNDVN_DIR_PIN <WNDVN_DIR_PIN>` parameter (0=AbsoluteEncoder1, 1=AbsoluteEncoder2).
+
+
+Wind Vane Construction
+++++++++++++++++++++++
+A 3D-Printable model for an absolute encoder win-vane is available on `thingiverse <https://www.thingiverse.com/thing:4247123>`__. This example 
+uses an AS5048B breakout board and diametrically polarized magnet available `here <https://www.digikey.com/en/products/detail/ams/AS5048A-TS_EK_AB/3188612>`__.

rover/source/docs/wind-vane.rst

@@ -27,7 +27,7 @@ to a alternative sensor. Note that any change to the _TYPE parameters will requi
 
 Wind Direction
 ----------------------
-Wind direction can be directly sensed through the use of an analogue voltage input. However it is also possible to use a fixed wind direction,
+Wind direction can be directly sensed through the use of a directional sensor. However it is also possible to use a fixed wind direction,
 this is not recommended for long term use, but will allow testing of sailboats without the need for specialist sensors. The wind vane type can be
 selected with :ref:`WNDVN_TYPE <WNDVN_TYPE>`. The wind direction is filtered using a low pass filter, the frequency of this filter can be set 
 using :ref:`WNDVN_DIR_FILT <WNDVN_DIR_FILT>`. If the wind direction is oscillating this frequency can be reduced. This will reduce the effect
@@ -42,6 +42,8 @@ the vehicle will have no new information about wind direction.
 
     Analogue Wind Vane <wind-vane-analogue>
     Home Heading <wind-vane-home-heading>
+    Absolute Encoder Wind Vane <wind-vane-absolute-encoder>
+    NMEA <wind-vane-NMEA>
 
 
 Wind Speed
@@ -59,4 +61,4 @@ speed is filtered using a low pass filter, the frequency of this filter can be s
     RPM <wind-vane-rpm>
     Modern Devices rev-p <wind-vane-MD-rev-p>
     Connecting Bluetooth Windvane to ArduPilot <https://github.com/ArduPilot/ardupilot/blob/master/libraries/AP_WindVane/Tools/Bluetooth%20NMEA%20receiver/Bluetooth%20NMEA%20receiver.md>
-
+    NMEA <wind-vane-NMEA>