
• #2
I think something like this will do what you want:
Serial3.setup (115200, {rx: P0, tx: P1}); var lastData; var gps = require ("GPS"). connect (Serial3, function (data) { console.log (data); if (lastData) { // do stuff here  eg. the difference between the two readings var dlat = data.lat  lastData.lat; var dlon = data.lon  lastData.lon; } lastData = data; });
Although as you say, you might be able to extract the data that you want from other NMEA data. For instance
VTG
Velocity made good
sounds promising 
• #3
Wow great. it works!!!
Serial3.setup (115200, {rx: P0, tx: P1}); var lastData; var gps = require ("GPS"). connect (Serial3, function (data) { if (lastData) { // do stuff here  eg. the difference between the two readings var dlat =data.time; // var dlon = data.lon  lastData.lon; console.log (dlat); console.log ('*>',lastData); } lastData = data.time; // return lastData; });

• #4
In general, going on the path 1 with yours help, I wrote such code, but there are some strange mistakes = (such as 45 km / h at rest). I tested it in my car. Visually it coincides with the speedometer in my smartphone =)
//********* Serial3.setup (115200, {rx: P0, tx: P1}); var R = 6371e3; // var Led= require('@amperka/led').connect(A1); var lastData; // var lastData2; // var lastLon; // var lastLat; // var LastTime; var toRad=Math.PI/180; var i=0; var gps = require ("GPS"). connect (Serial3, function (data) { if (lastData,i<50) { // do stuff here  eg. the difference between the two readings //****** distance calc var Lon=data.lon*toRad; // lon в t1 var Lat=data.lat*toRad; //lat в t1 var diffLon=Math.abs(LonlastLon*toRad); var diffLat= Math.abs(LatlastLat*toRad); var a= Math.sin(diffLat/2) * Math.sin(diffLat/2) + Math.cos(Lat) * Math.cos(lastLat*toRad) * Math.sin(diffLon/2) * Math.sin(diffLon/2); var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1a)); var distansP = R * c; //****** time diff var tTime= data.time.split(':'); // time array tTime=tTime[2]; var diffTime=tTimeLastTime; //****** speed var speed1= distansP/diffTime; // m/s var speed2= speed1*3.6; // km/h if(speed2>60){ Led.turnOn(); } else{Led.turnOff();} console.log(speed2,speed1); //console.log ('1',Math.sin(diffLat/2),diffLat/2,'2',Math.cos(Lat), '3',Math.cos(lastLat*toRad),lastLat*toRad,'4',Math.sin(diffLon/2),'5',Math.sin(diffLon/2),'6',Math.sqrt(a),a,'7',Math.sqrt(1a),'8',diffTime ); Debugging } lastData=data; lastLon=data.lon; // in degrees lastLat=data.lat; //in degrees LastTime= data.time.split(':'); LastTime= LastTime[2]; // lastData = data.time.split(':'); //lastData2 = lastData[2]; // lastLon= data.lon; i=i+1; });
Hi guys!
I want to get the speed and, depending on it do an actions, for example, to light the LED.
I see 2 ways of solving this problem.
the first one
Use the standard Esprino library, taken from the link below.
https://www.espruino.com/GPS
The following data is displayed:
There is no speed but I can get it if i know Time1 and Time0 and latitude, longitude at Time1, Time0.
I can colculat the distance pased using formulas from there http://www.movabletype.co.uk/scripts/latlong.html.
, then devide it on diff betvin T1 and T0
The problem is
How get latitude, longitude at T1, T0 from this code?
Serial3.setup (115200, {rx: P0, tx: P1});
var gps = require ("GPS"). connect (Serial3, function (data) {
console.log (data);
});
if i try somth like this
i get empty valus in console.
.
the second way is to communicate with serial
I use such cod
Problem
As a result, it get all data from GPS controller but here http://www.gpsinformation.org/dale/nmea.htm
I have not found any messages with such codes, and accordingly I do not understand what position, what it means, and how it's to pars it to get the speed. How to pars the
NMEA sentent ?