Initial Version

MATLAB/+XPlaneConnect/readUDP.m

@@ -0,0 +1,79 @@
+function [ data ] = readUDP( input )
+%readUDP Read Array from UDP Socket
+% Version 0.25
+% 
+% Inputs
+% 	input: Either an opened UDP Socket or integer port number
+% 
+% Outputs
+%   data: UDP uint8 Array. Equal to -998 in the case of an error
+% 
+% Use
+% 1. import XPlaneConnect.*;
+% 2. socket = openUDP(49005);
+% 3. data = readUDP(socket);
+% 4. status = closeUDP(socket);
+% 
+% or
+% 
+% 1. import XPlaneConnect.*;
+% 2. data = readUDP(49005);
+% 
+% NOTE: sending in a port number instead of an opened socket clears the 
+%UDP buffer. This only works if the data is being sent at a fast rate. 
+%Sending in a UDP Socket reads the first packet in the buffer. 
+%
+% Change Log
+%  10/02/14: [CT] V0.25: Updated to work with updated xpcPlugin
+%  04/18/14: [CT] V0.2: Added Versioning
+%  09/08/13: [CT] Added option for either UDP Socket or port number input
+%  06/10/13: [CT] Code created
+%
+% Contributors
+%   [CT] Christopher Teubert (SGT, Inc.)
+%       christopher.a.teubert@nasa.gov
+%
+% To Do
+% 1. Verify Input
+%
+% BEGIN CODE
+
+    import XPlaneConnect.*
+    import java.net.DatagramPacket
+    bits = 2000;
+    
+    %% Interpret Input
+    socket = input;
+    if isnumeric(input) 
+        socket=openUDP(input);
+    end
+    
+    %% Try reading packet
+    try
+        packet = DatagramPacket(zeros(1,bits,'int8'),bits);
+        socket.receive(packet)
+        data = packet.getData;
+        
+        data = int16(data);
+        data(data(:)<0) = uint8(data(data(:)<0) + 256); %fix signed issue
+        size = int16(data(5)); %size of data stream
+        
+        %% trim trailing data
+        for i=1:floor(length(data)/256)+1
+            if data(size+1:end)==0
+                break
+            end
+            size = size + 256;
+        end
+        data = data(1:size);
+        
+    catch err %Read Unsuccessful
+        data = -998;
+    end
+    
+    %% Close Port (if opened in code)
+    if isnumeric(input)
+        socket.close()
+    end
+end
+