Application for saving sensor data not working in background


for a medical study my goal is to obtain several sensor data (HRM, RR Intervall, Light, Pressure, Movement) and save them with the current time to a .txt file.

So far everything was working till I implemented the part to save the data. I could use the method for one sensor and then the app began to lag, if I try to save more than one sensor value, the app stops working completly. To save, I use the following code:


    function getHRM() {
    var hrm = 0.0;
    var rrintervall;
    function onGetSuccessCB(hrmInfo) {
        hrm = hrmInfo.heartRate;
        document.getElementById('hrm').innerHTML = ('hrm: ' + hrm + "<br />");
        rrintervall = hrmInfo.rRInterval;
        document.getElementById('rr-value').innerHTML = ('rr: ' + rrintervall + "<br />");
        tizen.filesystem.resolve("documents", function(dir) 
           file = dir.resolve("hrm.txt");
        function(fs) {
            fs.write(" " + hrm + " "+ tizen.time.getCurrentDateTime().toLocaleString()+";");
                }, function(e) {
                    console.log("Error " + e.message);
                }, "UTF-8");
    tizen.humanactivitymonitor.start('HRM', onGetSuccessCB);
Also I realized, that the app is not saving any data when the screen is turned off. Before saving the data, it was that, when the screen was turned off and I switched it on again, it felt like, the app was "rushing" through the values from the time when the screen was turned off. After I implemented the saving function I just didn't record any background data. 
Any ideas, what causes the problems? I read somewhere that it is not possible to record the data in the background without programming it in C but I could't verify it so far, is that true? 
I'm glad for every help, thanks.


1 Replies

anyone any ideas?