X-Git-Url: https://git.xandkar.net/?p=erlang-x-plane-data.git;a=blobdiff_plain;f=README.md;h=7cc34b87243dc06bc9395f22f0f051f1a0de5693;hp=c428cdb187ed7b43e1f6d4d8ecb2378bf617dfce;hb=c9410825c5416a62558ac6bd108a1dbe6ffbc3c6;hpb=3549a33ac1d2d49c8cef0b6cf679e90f9cc3c89a

diff --git a/README.md b/README.md
index c428cdb..7cc34b8 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,74 @@
 
 X-Plane UDP data parser
 =======================
+
+Example
+-------
+
+```erlang
+-include_lib("include/x_plane_data.hrl").
+
+main(Port) ->
+    {ok, Socket} = gen_udp:open(Port, [binary, {active, false}]),
+    {ok, {_, _, <<XPlaneDataPacket/binary>>}} = gen_udp:recv(Socket, 0),
+    {ok, XPlaneData} = x_plane_data:of_bin(XPlaneDataPacket),
+
+    % Currently there're 133 possible data types sent by X-Plane 10, of which
+    % I've identified and labeled only some of. See x_plane_datum:t() type for
+    % what is currently labeled.
+    % The types I've not yet labeled are in the format specified by
+    % x_plane_datum:anonymous() and can be looked-up by their index number.
+
+    % Find labeled data types
+    {some, #x_plane_datum_speeds
+        { vind_kias   = VindKias
+        , vind_keas   = VindKeas
+        , vtrue_ktas  = VtrueKtas
+        , vtrue_ktgs  = VtrueKtgs
+        , vind_mph    = VindMph
+        , vtrue_mphas = VtrueMphas
+        , vtrue_mphgs = VtrueMphgs
+        },
+    } = hope_kv_list:get(XPlaneData, speeds),
+
+    {some, #x_plane_datum_pitch_roll_heading
+        { pitch_deg  = PitchDeg
+        , roll_deg   = RollDeg
+        , hding_true = HdingTrue
+        , hding_mag  = HdingMag
+        },
+    } = hope_kv_list:get(XPlaneData, pitch_roll_heading),
+
+    {some, #x_plane_datum_lat_lon_alt
+        { lat_deg   = LatDeg
+        , lon_deg   = LonDeg
+        , alt_ftmsl = AltFtmsl
+        , alt_ftagl = AltFtagl
+        , on_runwy  = OnRunwy
+        , alt_ind   = AltInd
+        , lat_south = LatSouth
+        , lon_west  = LatWest
+        },
+    } = hope_kv_list:get(XPlaneData, lat_lon_alt),
+
+    % Find an unlabled data type
+    {some, {10, V1, V2, V3, V4, V5, V6, V7, V8}} = hope_kv_list:get(XPlaneData, 10),
+
+    % Attempt to find a data type that was not included in current packet
+    none = hope_kv_list:get(XPlaneData, 130),
+    none = hope_kv_list:get(XPlaneData, 67),
+
+    ...
+```
+
+Note: you can, of course, use any other method to search a `[{K, V}]` list
+(which is how `x_plane_data:t()` is structured), such as:
+`proplists:get_value/2`, `lists:keyfind/3`, etc., but I prefer the API of
+`hope_kv_list`, so I used that.
+
+
+Data format references
+----------------------
+
+- http://b58.svglobe.com/data.html
+- http://www.nuclearprojects.com/xplane/xplaneref.html