Develop Reference

Is HTML5 browser geolocation feature on mobile available while screen off/ suspend?

To substitute my usage of native apps that allow to keep track of my position, I wanted to generate a PWA using the HTML5 Goelocation API.
The result I have been able to achieve so far seems to point a inferior functionality of the HTML5 Goelocation API compared to native Android API.
Below is the code I have used and the issue is, that the PWA/ website application only receives infrequent updates. Additionally the app only receives position while the screen is not off.
This puts a huge obstacle into having a PWA being to track for instance my bike tour, since I cannot keep the screen and browser in the foreground, while ideed I wished the PWA would simply continues running even when the screen is off.
Now I am aware that in most cases a device user and privacy aware person would benefit from the useragent/browser to cut the waste of resources and limit privacy loss by disabling the very feature I search.
In essence however I have looked over the MDN documentation and besides the PositionOptions I was yet unable to find any clue about the guarantees of the API.
Find below the way I have sought to make it work as a code.
Does + Should HTML5 Goelocation API work when screen of on a mobile?
Is there a concrete information about if and how much geolocation information is returedn? like frequency/delay of update and like geofencing imprecision ?
Could for instance google maps navigation work in the browser itself?
My platform is Gecko on Android. If better results could be achieved in Chromium on Android I would be happy to hear about that too.
On Android I use firefox. In it I wanted to have my website provide a page that keeps track of my movements via the geolocation API, in order to replace my strave.
window.addEventListener("load",function(){
var a= document.createElement("div");
var textarea = document.createElement("textarea");
//textarea.value="aaaa"
textarea.style.display="block"
textarea.style.minHeight="5cm"
textarea.style.width="100%"
document.body.appendChild(a);
document.body.appendChild(textarea);
if(confirm("reset data?")){
localStorage.clear() ;
}
localStorage.setItem("start"+Date.now(),startInfo);
var startInfo = Object.keys(localStorage).length+ " " +Date.now()+ " " + (Date.now() % 864000);
var lastTime=0,lastLat=0,lastLon=0,count=0,lastDistance=0;
var startTime = Date.now();
var distance = 0;
if('geolocation' in navigator) {
a.innerHTML="<h2>super wir haben geolocation!</h2>";
setInterval(()=>{
navigator.geolocation.getCurrentPosition((position) => {
// var a = document.createElement("div");
count++;
a.innerHTML="<h1>"+(((Date.now()-startTime)/1000)|0)+" "+((distance*100|0)/100)+"</h1><h3>"+startInfo+"</h3><h2>date="+(new Date()).toString()+"<br>lang="+position.coords.latitude+" long="+ position.coords.longitude+"</h2>";
var lat = ((position.coords.latitude * 10000000) | 0)
var lon = ((position.coords.longitude * 10000000) | 0)
var time = Date.now();
var deltaTime = time - lastTime;
var deltaLat = lat - lastLat;
var deltaLon = lon - lastLon;
if(Math.abs(deltaLat)>100000 || Math.abs(deltaLon) > 100000)
{
} else{
distance += Math.sqrt(deltaLat*deltaLat+deltaLon*deltaLon);
}
var deltaDistance = distance - lastDistance;
lastLat=lat;
lastLon=lon;
lastTime=time;
lastDistance=distance;
newline = (((Date.now()-startTime)/1000)|0) + " dist=" + distance + "("+deltaDistance+") lat=" + lat + "("+deltaLat+") lon=" + lon + "("+deltaLon+") ";
textarea.value = newline + "\n" + textarea.value;
localStorage.setItem("P"+(Date.now()%864000),deltaLat+" "+deltaLon+" "+deltaTime);
},function(){},{timeout:900});
},1000);
} else {
a.innerHTML="<h2> shit</h2>";
}
});

Not cheatable Google fit step counter

i have a question to Google Fit.
I am creating a step counter (oh wonder g). This i have already done so far and it not really hard.
But now we come to my problem. I am only reading the steps with the Sensor API. The issue is, i can add new data via for example the Google Fit app and it will be counted in my app too. This introduces cheating and i do not want this.
So i need to have a way to only read "device created" data and not manually added data. Is there a nice way to to this?
From the SDK documentation it is not really clear how to proceed here.

So i need to have a way to only read "device created" data and not
manually added data. Is there a nice way to to this?
You will want to use Private Custom Data Types to achieve that. Read about the different types of Fitness data you can upload to Google Fit here.
1. Public data types
Standard data types provided by the platform, like com.google.step_count.delta. Any app can read and write data of
these types. For more information, see Public Data Types.
2. Private custom data types
Custom data types defined by an specific app. Only the app that defines the data type can read and write data
of this type. For more information, see Custom Data Types.
3. Shareable data types
Custom data types submitted to the platform by an app developer. Once approved, any app can read data of a
shareable type, but only whitelisted apps as specified by the
developer can write data of that shareable type. For more information,
see Shareable Data Types.

I was able to do this with the help of this alogrithm. But remember due to Android fragmentation this code still removes some of the user's data and count it as penalty
private String dumpDataSet(DataSet dataSet, int x) {
List<String> days = new ArrayList<>();
days.add("Monday");
days.add("Tuesday");
days.add("Wednesday");
days.add("Thursday");
days.add("Friday");
days.add("Saturday");
days.add("Sunday");
String day = days.get(Math.round(x / 24));
Log.d(TAG, "\tDay: " + day);
Log.i(TAG, "Data returned for Data type: " + dataSet.getDataType().getName());
DateFormat dateFormat = getTimeInstance();
String text = "";
try {
for (DataPoint dp : dataSet.getDataPoints()) {
Log.i(TAG, "\tStepCount getStreamName: " + dp.getOriginalDataSource().getStreamName());
Log.i(TAG, "\tStepCount getStreamIdentifier: " + dp.getOriginalDataSource().getStreamIdentifier());
Log.i(TAG, "\tStepCount App Type: " + dp.getDataType().getName());
Log.i(TAG, "\tStepCount Type: " + dp.getOriginalDataSource().getType());
for (Field field : dp.getDataType().getFields()) {
Log.i(TAG, "\tField: " + field.getName() + " Value: " + dp.getValue(field));
text += dp.getValue(field);
String si[] = dp.getOriginalDataSource().getStreamIdentifier().toLowerCase().split(":");
if ((((si[si.length - 1].contains("soft")) || (si[si.length - 1].contains("step"))) && si[si.length - 1].contains("counter"))) {
totalSteps += Integer.parseInt(dp.getValue(field).toString());
Log.d(TAG, "\tStepCount" + " Added Steps -> " + dp.getValue(field) + " steps");
text += "\n\n";
} else {
Log.e(TAG, "\tStepCount PENALTY ---------------------------------------------------------------");
Log.e(TAG, "\tDay = " + day + " | Hour Number = " + x + " | StepCount" + " PENALTY DEDUCTED -> " + dp.getValue(field) + " steps");
Log.e(TAG, "\tStepCount PENALTY getStreamIdentifier: " + dp.getOriginalDataSource().getStreamIdentifier());
Log.e(TAG, "\tStepCount PENALTY getStreamName: " + dp.getOriginalDataSource().getStreamName());
Log.e(TAG, "\tStepCount PENALTY App Type: " + dp.getDataType().getName());
Log.e(TAG, "\tStepCount PENALTY Type: " + dp.getOriginalDataSource().getType());
Log.e(TAG, "\tStepCount PENALTY ---------------------------------------------------------------");
}
}
}
} catch (Exception ex) {
ex.getStackTrace();
}
return text;
}
----- UPDATE -----
You can also call
DataPoint.getOriginalDataSource().getAppPackageName()
to filter out smartwatches and other apps.

I tried as suggested by Ali Shah lakhani but
DataPoint.getOriginalDataSource().getAppPackageName();
/*I also tried but could not achieve what I wanted*/
DataPoint.getOriginalDataSource().getStreamName();
DataPoint.getOriginalDataSource().getStreamIdentifier();
did not work at least for me while retrieving data. I ended up using readDailyTotalFromLocalDevice() as shown below in order to capture steps captured by device only.
Fitness.HistoryApi.readDailyTotalFromLocalDevice(mApiClient, DataType.TYPE_STEP_COUNT_DELTA).await(1, TimeUnit.MINUTES)
I cross checked the same with some of the apps that avoids manual entries in their app and the count provided by the function above is exactly the same.
Note: If a user is having multiple devices and is using the app on all of them, readDailyTotalFromLocalDevice() will have different value for each and every device since the function is responsible for returning device specific data only.

android mathematical calculations in eclipse java

Can anybody tell me why the result of the following expression is -4.91679930495
9.81*Math.cos(phi)/Math.sin(phi)
if phi = 90°?
In particular, I want to display the value of acceleration.
tvText2.setText("acceleration: " + String.valueOf(9.81*Math.cos(phi)/Math.sin(phi)) + " m/s²");

Acording to docs http://docs.oracle.com/javase/7/docs/api/java/lang/Math.html#cos(double):
The paremeter of those methods is in radians.
you will need to call Math.toRadians that receives an angle in degrees. http://docs.oracle.com/javase/7/docs/api/java/lang/Math.html#toRadians(double)

Convert phi to Radian before calculating acceleration:
double phiInRad = Math.toRadians(phi);
tvText2.setText("acceleration: " + String.valueOf(9.81*Math.cos(phiInRad)/Math.sin(phiInRad)) + " m/s²");
or in one line
tvText2.setText("acceleration: " + String.valueOf(9.81*Math.cos(Math.toRadians(phi))/Math.sin(Math.toRadians(phi))) + " m/s²");

Interpreting BluetoothGatt Value from Light Sensor

I am writing an app which is receiving values from a Light Sensor of a BLE device. I am trying to determine what it is that I am receiving. I am trying to get the Lux value which is provided by the sensor, but am concerned that it needs conversion. I do not know what the unit of measure is for this sensor. For example, the unit for an Android phone is SI Lux. Should be easy enough, but for this sensor, the specs do not state.
Here is the code which is giving me output:
case MSG_LIGHT:
characteristic = (BluetoothGattCharacteristic) msg.obj;
if (characteristic.getValue() == null) {
Log.w(TAG, "Error obtaining light value");
return;
}
int formatlgt1 = -1;
formatlgt1 = BluetoothGattCharacteristic.FORMAT_SINT8;
Log.i(LIGHT, "Light RawValue1 " + characteristic.getIntValue(formatlgt1, 0));
Log.i(LIGHT, "Light RawValue2 " + characteristic.getIntValue(formatlgt1, 1));
Log.w(LIGHT, "Light UUID " + characteristic.getUuid());
Log.w(LIGHT, "Light Stored Value " + characteristic.getValue());
Log.w(LIGHT, "Light Descriptors " + characteristic.getDescriptors());
Log.d(LIGHT, "Light Characteristic " + characteristic);
updateLightValues(characteristic);
break;
Simple enough, just read the sensor and give me the various outputs from that sensor at the time of reading. Next here is the output:
Light RawValue1 4
Light RawValue2 9
Light UUID 0000aa91-0000-1000-8000-00805f9b34fb
Light Stored Value [B#431d30b0
Light Descriptors [android.bluetooth.BluetoothGattDescriptor#4300e508, android.bluetooth.BluetoothGattDescriptor#4300eaf8]
Light Characteristic android.bluetooth.BluetoothGattCharacteristic#43002b10
I am interpreting that the measurement of this is the RawValues 1 & 2 but am logging what is stored to help. Problem is that the StoredValue is [B#431d30b0 which is beyond me. According to the description form the manufacturer, it states that the first byte is the HILUX at address 00x03 and the second is LOLUX at address 00x04 with a default value of 00:00.
What am I looking at here and where am I going wrong? Where I am hurting is my understanding of what I am reading. Can't seem to get a good search context to learn about it.
Thanks

How can I get exact GPS location with AIR Geolocation API?

How can I get the exact Latitude and Longitude? I only get whole numbers. From my understanding, in order to get down to the meter I need to get down to 5 decimal places. I have tried the horizontal and vertical accuracy but they don't match my phones GPS reading.
How can I get an exact GPS reading with Geolocation API, Down to the meter?
here is my code
var my_geo:Geolocation = new Geolocation();
my_geo.setRequestedUpdateInterval(2000);
my_geo.addEventListener(GeolocationEvent.UPDATE, onGeoUpdate);
function onGeoUpdate(e:GeolocationEvent):void
{
gpsLat1 = (e.latitude);
gpsLon1 = (e.longitude);
gpsHeading = (e.heading);
gpsHorAcc = (e.horizontalAccuracy);
gpsVerAcc = (e.verticalAccuracy);
gpsCheck = 2;
my_txt.text = "My Latitude is "+ gpsLat1 + " and my Longitude is "+ gpsLon1 + " Bearing is " + gpsHeading+ " HorAcc "+ gpsHorAcc+ " VertAcc "+gpsVerAcc;
}

Make sure your variables (gpsLat1, gpsLon1, gpsHeading, etc.) are of type Number and not a uint or int. Unsigned Integers and Integers only allow for whole numbers, whereas Number is the equivalent of float in most other languages (and allows for incredibly larger values, as well). If you save a decimal to an integer, it is rounded off/floored (I can't remember which), which sounds exactly like the problem you are having.
Alternatively, the API is restricted by the hardware you are testing on. If the hardware only returns a certain value for GPS coordinates, AIR cannot be any more precise. Odds are this is not the issue since a whole lat long point can be miles and miles in distance, meaning any device with that inaccurate of a GPS chip is absolutely useless.

Try this:
function onGeoUpdate(e:GeolocationEvent):void
{
gpsLat1 = (e.latitude.toString());
gpsLon1 = (e.longitude.toString());
gpsHeading = (e.heading.toString());
gpsHorAcc = (e.horizontalAccuracy.toString());
gpsVerAcc = (e.verticalAccuracy.toString());
gpsCheck = 2;
my_txt.text = "My Latitude is "+ gpsLat1 + " and my Longitude is "+ gpsLon1 + " Bearing is " + gpsHeading+ " HorAcc "+ gpsHorAcc+ " VertAcc "+gpsVerAcc;
}