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3 X-Plane UDP data parser
4 =======================
6 ![Data output in the cockpit](screenshot.png)
11 ### Receive data packet
14 {ok, Socket} = gen_udp:open(Port, [binary, {active, false}]),
15 {ok, {_, _, <<XPlaneDataPacket/binary>>}} = gen_udp:recv(Socket, 0),
21 {ok, {64=Index, GroupsRaw}=DataRaw} = x_plane_data_raw:of_bin(XPlaneDataPacket),
24 ### Access parsed data
28 At this stage, only the structure of the packet was parsed. No attempt at
29 interpreting the values have been made:
32 % Speeds are in group 3
33 {3, Speeds} = lists:keyfind(3, 1, GroupsRaw),
44 % Pitch roll and headings values are in group 17
45 {17, PitchRollHeadings} = lists:keyfind(17, 1, GroupsRaw),
54 } = PitchRollHeadings,
59 Here we identify what each of the numbered groups mean in a given X-Plane
60 version. Right now only X-Plane 10 (packet index 64) is supported and I only
61 identified 3 groups so far:
63 | packet index | group index | group name |
64 |--------------|-------------|----------------------|
66 | 64 | 17 | `pitch_roll_heading` |
67 | 64 | 20 | `lat_lon_alt` |
69 Unidentified groups (with index other than what is listed above) will be
70 absent from the list of named groups (think of `x_plane_data_named:of_raw/1` as
71 a filter), so you'll have to access their raw version, if needed.
75 {ok, {x_plane_data_v10, GroupsNamed}} = x_plane_data_named:of_raw(DataRaw),
80 -include_lib("x_plane_data/include/x_plane_data_group_speeds.hrl").
81 {speeds, #x_plane_data_group_speeds
82 { vind_kias = VindKias
83 , vind_keas = VindKeas
84 , vtrue_ktas = VtrueKtas
85 , vtrue_ktgs = VtrueKtgs
87 , vtrue_mphas = VtrueMphas
88 , vtrue_mphgs = VtrueMphgs
90 } = lists:keyfind(speeds, 1, GroupsNamed),
94 -include_lib("x_plane_data/include/x_plane_data_group_pitch_roll_heading.hrl").
95 {pitch_roll_heading, #x_plane_data_group_pitch_roll_heading
96 { pitch_deg = PitchDeg
98 , hding_true = HdingTrue
99 , hding_mag = HdingMag
101 } = lists:keyfind(pitch_roll_heading, 1, GroupsNamed),
108 <<"DATA", PacketIndex:8/integer, Groups/binary>>,
109 << GroupIndex:32/little-integer
110 , GroupValue1:32/little-float
111 , GroupValue2:32/little-float
112 , GroupValue3:32/little-float
113 , GroupValue4:32/little-float
114 , GroupValue5:32/little-float
115 , GroupValue6:32/little-float
116 , GroupValue7:32/little-float
117 , GroupValue8:32/little-float
122 Where `PacketIndex` indicates something like a schema version, i.e. what each
123 of the numbered groups means. For example, in X-Plane 10, packet index is 64
124 (character `"@"`) and group 3 contains speed data, in which the 8 group values
127 | Location | Label | Description |
128 |----------|---------------|-------------|
129 | 1 | `vind_kias` | Velocity indicated, in knots indicated airspeed. |
130 | 2 | `vind_keas` | Velocity indicated, in knots equivalent airspeed (the calibrated airspeed corrected for adiabatic compressible flow at the craft's current altitude). |
131 | 3 | `vtrue_ktas` | Velocity true (the speed of the craft relative to undisturbed air), in knots true airspeed. |
132 | 4 | `vtrue_ktgs` | Velocity true, in knots true ground speed. |
133 | 5 | | Unused. Contains a dummy value. |
134 | 6 | `vind_mph` | Velocity indicated, in miles per hour. |
135 | 7 | `vtrue_mphas` | Velocity true, in miles per hour airspeed. |
136 | 8 | `vtrue_mphgs` | Velocity true, in miles per hour ground speed. |
142 - `X-Plane_10_manual.pdf` (distributed with X-Plane 10)
143 - http://b58.svglobe.com/data.html
144 - http://www.nuclearprojects.com/xplane/xplaneref.html