function ft_realtime_jaga16proxy(cfg)

% FT_REALTIME_JAGA16PROXY reads continuous EEG data from a Jinga-Hi JAGA16 system

% through the UDP network interface and writes it to a FieldTrip buffer.

%

% The FieldTrip buffer is a network transparent server that allows the acquisition

% client to stream data to it. An analysis client can connect to read the data upon

% request. Multiple clients can connect simultaneously, each analyzing a specific

% aspect of the data concurrently.

%

% Use as

% ft_realtime_jaga16proxy(cfg)

%

% The configuration should contain

% cfg.port = number, UDP port to listen on (default = 55000)

% cfg.channel = cell-array with channel names, see FT_CHANNELSELECTION

% cfg.blocksize = number, in seconds (default = 0.5)

% cfg.decimate = integer number (default = 1)

% cfg.calibration = number, in uV per bit (default = 1)

% cfg.feedback = 'yes' or 'no' (default = 'no')

%

% The target to write the data to is configured as

% cfg.target.datafile = string, target destination for the data (default = 'buffer://localhost:1972')

% cfg.target.dataformat = string, default is determined automatic

%

% To stop this realtime function, you have to press Ctrl-C

%

% See also FT_REALTIME_SIGNALPROXY, FT_REALTIME_SIGNALVIEWER

% Copyright (C) 2015-2016, Robert Oostenveld

%

% This file is part of FieldTrip, see http://www.fieldtriptoolbox.org

% for the documentation and details.

%

% FieldTrip is free software: you can redistribute it and/or modify

% it under the terms of the GNU General Public License as published by

% the Free Software Foundation, either version 3 of the License, or

% (at your option) any later version.

%

% FieldTrip is distributed in the hope that it will be useful,

% but WITHOUT ANY WARRANTY; without even the implied warranty of

% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

% GNU General Public License for more details.

%

% You should have received a copy of the GNU General Public License

% along with FieldTrip. If not, see <http://www.gnu.org/licenses/>.

%

% $Id$

cfg = ft_checkconfig(cfg);

% set the defaults

cfg.port = ft_getopt(cfg, 'port', 55000);

cfg.channel = ft_getopt(cfg, 'channel', 'all');

cfg.precision = ft_getopt(cfg, 'precision', 'single');

cfg.demean = ft_getopt(cfg, 'demean', 'yes');

cfg.decimate = ft_getopt(cfg, 'decimate', 1);

cfg.blocksize = ft_getopt(cfg, 'blocksize', 0.5); % seconds, this is only approximate

cfg.timeout = ft_getopt(cfg, 'timeout', 5); % seconds

cfg.calibration = ft_getopt(cfg, 'calibration', 0.2); % uv/bit

cfg.feedback = ft_getopt(cfg, 'feedback', 'yes');

cfg.target = ft_getopt(cfg, 'target', []);

cfg.target.datafile = ft_getopt(cfg.target, 'datafile', 'buffer://localhost:1972');

cfg.target.dataformat = ft_getopt(cfg.target, 'dataformat', []); % default is to use autodetection of the output format

% in principle this could be implemented using the MATLAB UDP object,

% but that requires the Mathwoks Instrument Control Toolbox

% this requires an external toolbox for the TCP communication

ft_hastoolbox('tcp_udp_ip', 1);

% ensure that the persistent variables inside these functions are reinitialized

clear pnet

clear buffer

% start listening on the UDP port

con = pnet('udpsocket', cfg.port);

if (con<0)

ft_error('unable to establish connection with host');

else

fprintf('listening on UDP port %d\n', cfg.port);

end

% I am not sure whether this has any effect

pnet(con, 'setreadtimeout', cfg.timeout)

% part of this is hard coded for the Jinga-Hi JAGA16

hdr = [];

hdr.Fs = 1000; % sampling frequency, is updated further down

hdr.nChans = 16; % number of channels, is updated further down

hdr.nSamples = 0; % number of samples

hdr.nSamplesPre = 0; % number of pre-trigger samples, not used

hdr.nTrials = 1; % number of trials, represent as a continuous strea,

hdr.label = cell(16,1); % Nx1 cell-array with the label of each channel

for i=1:hdr.nChans

hdr.label{i} = sprintf('%d', i);

end

% determine the selection of channels to be transmitted

cfg.channel = ft_channelselection(cfg.channel, hdr.label);

chanindx = match_str(hdr.label, cfg.channel);

% update the header according to the selection

hdr.nChans = numel(chanindx);

hdr.label = hdr.label(chanindx);

count = 0;

dat = cast([], cfg.precision);

while (true)

% read a packet

buf = [];

while isempty(buf)

siz = pnet(con,'readpacket');

buf = pnet(con, 'read');

if isempty(buf)

pause(43/1023);

end

end

packet = jaga16_packet(buf, false);

if strcmp(cfg.feedback, 'yes')

fprintf('received packet\n');

end

% do some sanity checks on the hard-coded parameters

assert(packet.nchan==16);

assert(packet.nbit==16);

% update the sampling frequency

hdr.Fs = packet.fsample;

% get the data and do some minimal conditioning

buf = double(packet.dat(chanindx,:));

if strcmp(cfg.demean, 'yes')

% the data is uint16 and hovers around 32768

buf = buf - double(intmax('uint16')/2);

end

if cfg.calibration~=1

buf = cfg.calibration * buf;

end

buf = cast(buf, cfg.precision);

% concatenate the data fragments until we have a complete block

dat = cat(2, dat, buf);

if size(dat,2) < hdr.Fs*cfg.blocksize

continue

end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% from here onward it is specific to writing the data to another stream

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% only write every Nth sample

% this is a kludge, as it drops occasional samples and ignores aliassing

if cfg.decimate~=1

hdr.Fs = hdr.Fs/cfg.decimate; % update the sampling frequency

dat = dat(:,1:cfg.decimate:end);

end

count = count + 1;

if strcmp(cfg.feedback, 'yes')

fprintf('writing %d channels, %d samples\n', size(dat,1), size(dat,2));

end

if count==1

% flush the file, write the header and subsequently write the data segment

ft_write_data(cfg.target.datafile, dat, 'header', hdr, 'dataformat', cfg.target.dataformat, 'chanindx', chanindx, 'append', false);

else

% write the data segment

ft_write_data(cfg.target.datafile, dat, 'header', hdr, 'dataformat', cfg.target.dataformat, 'chanindx', chanindx, 'append', true);

end

if cfg.decimate~=1

% revert the updated sampling frequency

hdr.Fs = hdr.Fs*cfg.decimate;

end

% start with an empty data block for the next iteration

dat = cast([], cfg.precision);

end % while true

% FIXME close the connection, this should be handled in some try-catch statement

pnet(con, 'close');