TG_Connect () returning minus value

The code:

function readRAW
%run this function to connect and plot raw EEG data
%make sure to change portnum1 to the appropriate COM port

clear all
close all

data = zeros(1,256);    %preallocate buffer

portnum1 = 6;   %COM Port #
comPortName1 = sprintf('\\\\.\\COM%d', portnum1);

% Baud rate for use with TG_Connect() and TG_SetBaudrate().
TG_BAUD_57600 =      57600;

% Data format for use with TG_Connect() and TG_SetDataFormat().
TG_STREAM_PACKETS =     0;

% Data type that can be requested from TG_GetValue().
TG_DATA_RAW =         4;

%load thinkgear dll
loadlibrary('Thinkgear.dll');
fprintf('Thinkgear.dll loaded\n');

%get dll version
dllVersion = calllib('Thinkgear', 'TG_GetDriverVersion');
fprintf('ThinkGear DLL version: %d\n', dllVersion );

Get a connection ID handle to ThinkGear

connectionId1 = calllib('Thinkgear', 'TG_GetNewConnectionId');
if ( connectionId1 < 0 )
    error( sprintf( 'ERROR: TG_GetNewConnectionId() returned %d.\n', connectionId1 ) );
end;

% Set/open stream (raw bytes) log file for connection
errCode = calllib('Thinkgear', 'TG_SetStreamLog', connectionId1, 'streamLog.txt' );
if( errCode < 0 )
    error( sprintf( 'ERROR: TG_SetStreamLog() returned %d.\n', errCode ) );
end;

% Set/open data (ThinkGear values) log file for connection
errCode = calllib('Thinkgear', 'TG_SetDataLog', connectionId1, 'dataLog.txt' );
if( errCode < 0 )
    error( sprintf( 'ERROR: TG_SetDataLog() returned %d.\n', errCode ) );
end;

% Attempt to connect the connection ID handle to serial port "COM3"
errCode = calllib('Thinkgear', 'TG_Connect',  connectionId1,comPortName1,TG_BAUD_57600,TG_STREAM_PACKETS );
if ( errCode < 0 )
    error( sprintf( 'ERROR: TG_Connect() returned %d.\n', errCode ) );
end

fprintf( 'Connected.  Reading Packets...\n' );
%record data

j = 0;
i = 0;
while (i < 10240)   %loop for 20 seconds
    if (calllib('Thinkgear','TG_ReadPackets',connectionId1,1) == 1)   %if a packet was read...

          if (calllib('Thinkgear','TG_GetValueStatus',connectionId1,TG_DATA_RAW) ~= 0)   %if RAW has been updated 
              j = j + 1;
              i = i + 1;
              data(j) = calllib('Thinkgear','TG_GetValue',connectionId1,TG_DATA_RAW);
          end
      end

      if (j == 256)
          plotRAW(data);            %plot the data, update every .5 seconds (256 points)
          j = 0;
      end

end

%disconnect             
calllib('Thinkgear', 'TG_FreeConnection', connectionId1 );

This error came up but I do not know what it means or how to solve it.

>> readRAWnew
Thinkgear.dll loaded
ThinkGear DLL version: 22
Error using readRAWnew (line 56)
ERROR: TG_Connect() returned -2.

Answer 1

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/277429-i-am-using-mindwave-mobile-have-problem-to-data-acquition-in-matlab