My applcation description:
The application will generate the user location everywhere and everyime 24/7.
The other app which browse the locations of the user will show him the locations with 1-10 minute spaces(I havn't decided yet) and of course that the location record that will be printed will be the most accurate.
I have tried diffrent type of things but I can't get the most accurate location for a minute for example.
Many suggested to send to the requestLocationUpdate a minute as a parameter but then it will generate every minute a location but I want to get the most accurate location in that minute so I guess I will have too generate all of that minute locations and choose the most accurate.
I came across many errors such as getting a city level location which is pretty bad(You have been in xx:xx at new york city.. I'm not looking for that).
There are many considerations such as battery safe and accuracy.
I'm agree to compromise about the amount of locations (means print every 10 minute the user location instead of 1 minute).
Anyway I'm so confused, if someone got a plan (not code level) how to manage that system I would like to hear.
The GPS location provider should give you precision of meters if you are in open air. If you take samples every minute with requestLocationUpdate, that should be enough.
It is not possible to "get N samples in a given time interval and keep only the most accurate one", you should do that calculation keeping a buffer of positions if you need that. In any case, I don't think it is worth the effort in this kind of applications.
The battery life is going to be a problem if you want a mobile device to last more than 4-6 hours with the GPS + internet connection active.
Related
I am developing an app which will give you nearby Mosques within 10 km of your current location. Now that the Places API allows a certain number of queries per day, I have used firebase to store nearby Mosques for a certain location and I first check if the data is in database or not before querying. But this still doesn't solve the problem. e.g. if a user is on the go the whole day then the results must be changing every single minute, according to his/her location. How can I achieve the desirable results?
As mentioned earlier, I am saving nearby locations in a database with their relative location (around which they exist). But this doesn't quite solve the problem.
Any help will be greatly appreciated.
Places API is a commercial offering - you are meant to pay for using it, if you want to make applications around it.
There's a certain small number of calls that you can do for free, but this is only meant as testing grounds or private use. I am no lawyer, but I would guess that circumventing the fee by scraping the map (like setting a bot to go around a country to build a database of points of interests) would be illegal and would probably get you a letter from Google saying you should stop.
Use AutocompleteSessionToken class to generate a token and place it after your key , this token will reduce your usage because you can request the places api multiple times and still it will be considered as a single request. i hope this will help cause i didnt get your question very well. here is sample of the link:
https://maps.googleapis.com/maps/api/place/autocomplete/json?input=1600+Amphitheatre&key=&sessiontoken=1234567890.
For more details.see here
I'm developing an android app using android studio. Basically, a user will take a picture of a landmark in the middle of nowhere, and walk to a road. During their walk, their location is recorded in a list every 5 seconds and once they reach a road, all of the recorded waypoints are sent to a database so other users can see how they got there.
The issue I'm having is that it isn't plausible for them to walk with their phones open, as they could be going on a difficult hike. What I want, is for their location to still be added to an array while the phone is in sleep mode.
I tried using an alarmManager but after I got it all figured out, I was informed that the minimum time between intervals is now set to 60,000 milliseconds which doesn't work at all because they will get very far after 60 seconds.
I also tried using wakelock but it didn't seem to work. A this point, I'm not even sure if this is possible, but I'm sure there is some sort of alternative. Any advice would be great at this point!
Is there any way to get the results like in this link having wrong date and time set on device? Thank you.
There's a way1 ...
Suppose that you have deliberately set the clock 1 minute slow.
Create a file that contains the number 60,000. When an application wants to find the correct time, it calls System.getTimeMillis() to get what the system thinks the time is. Then reads the number from the file and adds that number to the result of System.getTimeMillis().
Clearly, this is NOT a good idea, but then neither is deliberately setting the system clock incorrectly. (For a start, if the clock is miss-set, then you will have difficulty syncing it with an external time source like an NTP server. That means that your system's clock will drift.)
The problem i am working on is the TOTP algorithm. The thing I was wondering is how would it work if the time on server and the one on the device are not the same.
I see. The answer is that TOTP cannot work if the two clocks are not synchronized to within a small multiple of the timestep.
1 - There's another way too. Write an application that can do some image processing on a picture of a clock to read the time. Then hook this up to your computer's video camera, and point the camera at a cuckoo clock hanging on your wall. Make sure you wind up the clock regularly. If you want the date as well, point a second video camera at your Dilbert desk calendar.
I would like to implement GPS Tracking service. After a search on the web I'm still a bit confused on the best way to practice this feature.
I want to start following the user when he gets a mile away from his home.
I thought that the app will be installed at user's home and using:
locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
I'll get the user's coordinates and compare it with changing coordinates as he travels.
When the user gets away a mile from his home I'll send SMS messages with his maps location every predefined time interval.
I was wondering if there is someone who done something similar before and can recommend a best practice for this task.
Also, how accurate the GPS can be, and what might be the best practice to get distance?
Thanks in advance.
From my experience it is not a good idea to use GPS all the time to track when a user departs from his home location because it burns the battery in no time. I ended up learning the home location by looking at the cell tower IDs over night (assuming the user is at home then). If you reach a certain level of confidence that you know the user's home location you can ask him something like "Are you at home right now?" to be completely sure (although this is somehow creepy for many users).
If you follow this strategy you can start the GPS if the user connects to a new cell tower and save a lot of battery.
Regarding accuracy. You can get the accuracy provided with each Android.Location object. If you are outside, this is usually 5 or 10 meters. But be aware that there is only an 68% chance this value is correct, according to the documentation:
We define accuracy as the radius of 68% confidence. In other words, if you draw a circle centered at this location's latitude and longitude, and with a radius equal to the accuracy, then there is a 68% probability that the true location is inside the circle.
Be carefull, the getLastKnownLocation method will not necessary return the user home position.
You shoud rather get the current position. Most of the time, getLastKnownLocation is used to get a location quickly (avoiding heavy background work).
GPS accuracy depends on many factors:
Weather, quality of the chip, field, ...
But, most of the time, it's more accurate that the network provider.
Here a very good link : http://developer.android.com/guide/topics/location/strategies.html
You will learn a lot with that.
I have managed to read the web service to get current time of any given city.
I could get 2 important values from web service, current time (String) and the offset.
Question is
How to set time of any given city correctly?
Option 1:
Read machine/local time
Calculate UTC/GMT time out of machine time
City time = UTC time +/- offset value
But then what happens when machine time is wrong? You will also got
wrong time right?
Option 2:
Read current city time in String (2012-11-24 19:30)
Parse this time value and set it into Calendar
We got correct City time
But how about the next minute? Of course requesting the web service every minute to get current time is not a good solution right? Is it possible to maintain this Calendar instance keep running automatically every minute once we set it?
NB : I'm developing Android clock widget here.
Thanks
Option 1 is far better, in my eyes. Most cell phones have amazingly accurate time as time synchronization is an integral part of GSM and CDMA. Beyond that, I would far prefer a clock to work offline than to require internet connectivity.
If you are worried about ensuring accuracy in the face of incorrect system time, consider placing a call to a web service to get the current time for verification.
This verification could be done in the background, but keep in mind that web services are not the best time sync providers. I would let anything with under 5 minute difference go as it could be due to your server being out of sync or the call taking too long.