How do I export data coming from a sensor?

I have a robot that uses LiDAR and GPS to autonomously go to a waypoint (or will), and the devices I use, use telegraph communication. To accomplish this I am sending the comman, then in a while loop I am using fscanf to pick up the data that is coming in. Inside this loop the message is processed and parsed out to leave me with what I need.

Below is the example from the GPS code, I am pulling out the Latitude and Longitude values for waypoint navigation

 fwrite(gps, 'unlogall');
fwrite(gps, char(13));
fwrite(gps, char(10));
fwrite(gps, 'log COM1 bestposa ontime .05');
fwrite(gps, char(13));
fwrite(gps, char(10));
fwrite(gps, 'log COM1 bestvela ontime .05');
fwrite(gps, char(13));
fwrite(gps, char(10));

 while true  
bestpos = fscanf(gps);
bestvel = fscanf(gps);
posbegin = strsplit(bestpos, ',');
messagebegin1 = strcmp(posbegin, '#BESTPOSA');
velbegin = strsplit(bestvel, ',');
velbegin1 = strcmp(velbegin, '#BESTVELA');

    if all(messagebegin1 < 1) && all(velbegin1 <1)
        bestpos = fscanf(gps);
        bestvel = fscanf(gps);
    else 
        posstring = strsplit(bestpos, ';');
        velstring = strsplit(bestvel, ';');

        headermessage = char(posstring(1,1));
        header = strsplit(headermessage, ',');

        velheadmes = char(velstring(1,1));
        velheader = strsplit(velheadmes, ',');

        data3 = char(posstring(1,2));
        datamessage = strsplit(data3, ',');

        veldata = char(velstring(1,2));
        velmessage = strsplit(veldata, ',');

        PosSolution = cell2mat(datamessage(1));
        positiontype = cell2mat(datamessage(2));
        Latency = cell2mat(velmessage(3));
        HorizontSpeed = cell2mat(velmessage(5));
        Lat = cell2mat(datamessage(3));
        Long = cell2mat(datamessage(4));
    end 
end

How can I get the Lat and Long values outside of the while loop, updating at real time, so I can export them to other code to be integrated and processed to be then be used for motor commands. If that's possible, I also have other devices that will need to be integrated as well. I didn't want all 4 sensors to be run in the same code if possible. I have 3 serial, 1 TCPIP, which will be fed to a motor command "module"

Excuse my sloppy code I am fairly new to all of this.

Answer 1

[Tristan Yang]

Please consider using event-driven to work with the data. For both TCPIP and Serial communication, it is possible to work with an asynchronous callback function to process/parse data. Please check the following documentation page for the ' BytesAvailableFcn ':

To export data, you may then consider concatenate the data in the instrument object (both TCPIP and serial objects have UserData that can be used to store persistent data) to save them and/or process with the following:

1. You may use a timer object to further process the received data (e.g. generate motor commands) every certain period of time using the current UserData in serial and TCPIP objects:

2. You may also define a new function and pass in the function handle to the TCPIP/Serial async callback functions, so that each time new data is arrived, you may trigger the further processing function from it. Please refer to code below for an example:

t = tcpip('rhost',rport);
s1 = serial('COM1');
s2 = serial('COM2');
s3 = serial('COM3');
fcnHandle = @furtherOperationOnFullData;
receivingDataTCPIP(fcnHandle)

function furtherOperationOnTCPData(data)
    plot(data); % e.g plotting all the data
end

function receivingDataTCPIP(fcnHandle) % similar function for serials
    t = tcpip('127.0.0.1', 5000);
    t.BytesAvailableFcn = {@handleData, fcnHandle}; % pass along the function handle
    fopen(t);
end

function handleData(src, fcnHandle) % src is the TCPIP object
    if (isempty(src.UserData))
        src.UserData = zeros(1000,1);  % initializing, please customize
    elseif (numel(src.UserData) < 1000) % this is only receiving the first 1000 data points, please modify this for your use case
        src.UserData = [src.UserData, fread(t, src.BytesAvailable, 'int')]; % concatenate new data to old data
        fcnHandle(src.UserData); % actually calling the function furtherOperationOnFullData when data is all received
    else
        fclose(t); % close the connection to stop the callback
    end
end