README.md

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   2
   3 X-Plane UDP data parser
   4 =======================
   5
   6 Examples
   7 --------
   8
   9 ### Receive data packet
  10
  11 ```erlang
  12 {ok, Socket} = gen_udp:open(Port, [binary, {active, false}]),
  13 {ok, {_, _, <<XPlaneDataPacket/binary>>}} = gen_udp:recv(Socket, 0),
  14 ```
  15
  16 ### Parse data packet
  17
  18 ```erlang
  19 {ok, {64=Index, GroupsRaw}=DataRaw} = x_plane_data_raw:of_bin(XPlaneDataPacket),
  20 ```
  21
  22 ### Access parsed data
  23
  24 #### Raw
  25
  26 At this stage, only the structure of the packet was parsed. No attempt at
  27 interpreting the values have been made:
  28
  29 ```erlang
  30 % Speeds are in group 3
  31 {3, Speeds} = lists:keyfind(3, 1, GroupsRaw),
  32 { VindKias
  33 , VindKeas
  34 , VtrueKtas
  35 , VtrueKtgs
  36 , _
  37 , VindMph
  38 , VtrueMphas
  39 , VtrueMphgs
  40 } = Speeds,
  41
  42 % Pitch roll and headings values are in group 17
  43 {17, PitchRollHeadings} = lists:keyfind(17, 1, GroupsRaw),
  44 { PitchDeg
  45 , RollDeg
  46 , HdingTrue
  47 , HdingMag
  48 , _
  49 , _
  50 , _
  51 , _
  52 } = PitchRollHeadings,
  53 ```
  54
  55 #### Named
  56
  57 Here we identify what each of the numbered groups mean in a given X-Plane
  58 version. Right now only X-Plane 10 is supported and I only identified 3 groups
  59 so far:
  60
  61 - index: `3` , name: `speeds`
  62 - index: `17`, name: `pitch_roll_heading`
  63 - index: `20`, name: `lat_lon_alt`
  64
  65 Unidentified groups (with index other than what is listed above) will be
  66 absent from the list of named groups (think of `x_plane_data_named:of_raw/1` as
  67 a filter), so you'll have to access their raw version, if needed.
  68
  69 ##### Identify
  70 ```erlang
  71 {ok, {x_plane_data_v10, GroupsNamed}} = x_plane_data_named:of_raw(DataRaw),
  72 ```
  73
  74 ##### Access
  75 ```erlang
  76 -include_lib("x_plane_data_group_lat_lon_alt.hrl").
  77 -include_lib("x_plane_data_group_pitch_roll_heading.hrl").
  78 -include_lib("x_plane_data_group_speeds.hrl").
  79
  80 ...
  81
  82 {speeds, #x_plane_data_group_speeds
  83     { vind_kias   = VindKias
  84     , vind_keas   = VindKeas
  85     , vtrue_ktas  = VtrueKtas
  86     , vtrue_ktgs  = VtrueKtgs
  87     , vind_mph    = VindMph
  88     , vtrue_mphas = VtrueMphas
  89     , vtrue_mphgs = VtrueMphgs
  90     }
  91 } = lists:keyfind(speeds, 1, GroupsNamed),
  92
  93 {pitch_roll_heading, #x_plane_data_group_pitch_roll_heading
  94     { pitch_deg  = PitchDeg
  95     , roll_deg   = RollDeg
  96     , hding_true = HdingTrue
  97     , hding_mag  = HdingMag
  98     }
  99 } = lists:keyfind(pitch_roll_heading, 1, GroupsNamed),
 100 ```
 101
 102 Data format references
 103 ----------------------
 104
 105 - http://b58.svglobe.com/data.html
 106 - http://www.nuclearprojects.com/xplane/xplaneref.html