GeGaX
commented
3 years ago Hi Michael 😉,
I dug this limit story to 82 bytes.
This is actually a standard that says a maximum of 82 characters for one sentence. ("$", "*", 2 Hexadecimal characters included, <CR><LF> excluded)
With this info it is possible to increase the precision of the transmitted VR values.
formatHHMMSSSS()
Add MilliSeconds, if VR changes anything in the Client <=> Server iterations, there will be no code changes as it will already be in place.
function formatHHMMSSSS(d) {
var s = ""
+ pad0(d.getUTCHours())
+ pad0(d.getUTCMinutes())
+ pad0(d.getUTCSeconds())
+ "."
+ pad0(d.getUTCMilliseconds(), 3);
return s;
}formatNMEALatLon()
6 decimals (fixed) for better precison.
function formatNMEALatLon(l, len) {
var deg = Math.trunc(l);
var min = pad0(((l - deg) * 60).toFixed(6));
var result = "" + deg + min;
return pad0(result, len);
}$--RMC
Talker ID is GP not GN (I have never seen it, I will look more closely on my next installation). len Lat 9 => 11. len Lon 10 => 12. Replace roundTo() by .toFixed().
function formatGPRMC(m) {
var d = new Date(m.lastCalcDate);
var s = "GPRMC";
s += "," + formatHHMMSSSS(d) + ",A";
s += "," + formatNMEALatLon(Math.abs(m.pos.lat), 11);
s += "," + ((m.pos.lat < 0) ? "S":"N");
s += "," + formatNMEALatLon(Math.abs(m.pos.lon), 12);
s += "," + ((m.pos.lon < 0) ? "W":"E");
s += "," + m.speed.toFixed(5);
s += "," + m.heading.toFixed(5);
s += "," + formatDDMMYY(d);
s += ",,";
s += ",A";
return s;
}$--MWV
Talker ID is II not IN. Remove pad0() and roundTo().
function formatIIMWV(m) {
var s = "IIMWV";
s += "," + (m.twa > 0) ? m.twa : m.twa + 360 + ",T";
s += "," + m.tws + ",N";
s += ",A"
return s;
}sendNMEA()
Modify with right talker IDs
function sendNMEA() {
if (cbNMEAOutput.checked) {
races.forEach(function (r) {
if (r.curr) {
var rmc = formatGPRMC(r.curr);
var mwv = formatIIMWV(r.curr);
sendSentence(r.id, "$" + rmc + "*" + nmeaChecksum(rmc));
sendSentence(r.id, "$" + mwv + "*" + nmeaChecksum(mwv));
}
});
}
}$--WPL
Here I saw things too easy ... Looks like there are at least 3 sentences ($WPL, $RMB & $RTE). I will log the sentences on a real installation then I will come back to you 😉
mak08
amoutiers
Hi Michael 😉, I would like to suggest several points about NMEA:
• Send the HDG, TWA, TWS & SPD in raw VR values ( without roundTo() ) in sentences $INRMC & $INMWV. It works for me, on QtVlm and on another router. (If it works on these two, I think it works for all real routers). If the sentence does not exceed 82 bytes, it is valid.
• Send the NMEA sentence $INWPL (= Waypoints)
The projection could be dotted to visualize that it is a Wpt.