GPS code/module/library leaking memory before 'satellite lock' occurs

Hi - thanks for letting me know, and for including the traces... That's an odd one - there doesn't appear to be any obvious cause of the leak. The GPS code is actually pretty simple, see: https://github.com/espruino/EspruinoDocs/blob/master/devices/GPS.js

All I can think is that the GPS doesn't send any newline characters while it is searching for a lock, but that doesn't explain the permanent leak.

Unfortunately as it is, it's hard to see what the problem is, or what the data being read is. Can you try:

var exports = {};

function handleGPSLine(line, callback) {
  var tag = line.substr(3,3);
  if (tag=="GGA") {
    var d = line.split(",");
    var dlat = d[2].indexOf(".");
    var dlon = d[4].indexOf(".");
    callback({
      time : d[1].substr(0,2)+":"+d[1].substr(2,2)+":"+d[1].substr(4,2),
      lat : (parseInt(d[2].substr(0,dlat-2),10)+parseFloat(d[2].substr(dlat-2))/60)*(d[3]=="S"?-1:1),
      lon : (parseInt(d[4].substr(0,dlon-2),10)+parseFloat(d[4].substr(dlon-2))/60)*(d[5]=="W"?-1:1),
      fix : parseInt(d[6],10),
      satellites : parseInt(d[7],10),
      altitude : parseFloat(d[9])
    });
  }
}


exports.connect = function(serial, callback) {
  var gps = { line : "" };
  serial.onData(function(d) {
    if (d.data=="\n") {
      var line = gps.line;
      gps.line="";
      handleGPSLine(line, callback);      
    } else gps.line+=d.data;
  });
  return gps;
}

Serial4.setup(9600,{tx:C10,rx:C11});
var gps = exports.connect(Serial4, function (data) {
        if ((data.time.substr(-2))=="00") {
            console.log("time = "+data.time);
            console.log("lat = "+data.lat);
            console.log("lon = "+data.lon);
        }
});

Then you should be able to check on what gps.line is. Perhaps you could also change the beginning of serial.onData(function(d) { to:

serial.onData(function(d) {
  USB.write(d);
  ...

That'll spam loads of stuff over the console, but it will show you what data Espruino is getting from the GPS while it's waiting for a lock.