Add some examples to README

[erlang-x-plane-data.git] / README.md

diff --git a/README.md b/README.md
index 8092061..73d7f93 100644 (file)
--- a/README.md
+++ b/README.md
@@ -3,6 +3,43 @@
 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 a labeled data type
+    {some, #x_plane_datum_speeds{}} = hope_kv_list:get(XPlaneData, speeds),
+    {some, #x_plane_datum_pitch_roll_heading{}} = hope_kv_list:get(XPlaneData, pitch_roll_heading),
+    {some, #x_plane_datum_lat_lon_alt{}} = 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
 ----------------------