I'm writing an app with flutter to communicate with a weather station. The smartphone/tablet have to send via usb a command every one minute, recieve data from the station, and then send this data in a Firebase database.
I know that a smartphone is not the best device for do this, but I'm using an old device and I don't care about battery health (maybe a raspberry could be a better solution).
I'm using usb_serial package to communicate via usb and cron package for timing the events. And all works fine.
The problem is that the app have always to run in foreground. The first solution that i tried is using two apps: (1) one that keeps the screen on (2) and another that makes the screen black to reduce the energy consumpion. This is not the best solution.
I think that a better way is to use a background execution. I made some attempts with workmanager package but the minimum frequency is 15 min, with android alarm manager package but I'm not sure that wakes up also the network connection.
Anybody can suggest me witch is the best way to achieve my goal?
Thanks.
Refer this answer https://stackoverflow.com/a/14946013/13892187
In Dart for setting a recurring function we use the Timer class
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I'm developing a location aware app. This app will start tracking users when they are in their workday. These are the requirements:
The service should run on a regular basis (every 30 or 45 min).
It won't matter if the service does not trigger at the same basis everytime.
The service needs to upload data to our firestore db.
I doesn't need to be triggered on specific conditions (data is on, phone is charging, etc...)
I need this to run even if the user restarts his phone.
We may need to track the distance traveled by the user. (This is not a requirement per se, but it may be a feature someday)
I know there are a lot of ways to achieve this, but I have not decided which is the option that best fits my scenario. This is what I've thought so far:
Foreground service combined with BroadcastReciever in case the phone is rebooted
Background service using the new jetpack's Workmanager.
Which will the best solution? Do you think there is a better solution than those?
Thanks!
Was thinking create a GPS location tracker so when they are in work premise as well as outside it kinda shows.
Then consider adding the number 5 of the above. Like you said there could be mire awesome solutions than these so lets wait for options.
I am developing an android app for our custom healthcare hardware device that, among other things, should receive data from 5 sensos. The sensor data are sent via Bluetooth and is received using delegates that fire at 64Hz, 1000Hz, 4Hz,4Hz, and 32Hz respectively. I have successfully created an app that received the sensor data. Unfortunately, at the moment, the sensor acquisition runs on the main UI thread. This is unacceptable because it is expected that the app should keep recording the data uninterrupted throughout the day. After spending some time exploring my options, many tutorial online suggest to use a service to achieve this. However, there are many types of services (IntentServices, foreground services, background services...) to choice from and I am not sure what is the best approach. Also, my app will target android O and it seems that using background services are somehow discouraged. Would any experienced android developer gives some suggestion on how to tackle this problem? Please note that, at the moment, this is just a demo and the battery and other resource usage is not an issue.
Best approach for things that you want to achieve is to use Foreground Service, that will keep connection with ble device and get notifications from gatt services. Also you will need to use WakeLock to keep your service alive in sleep mode.
One year ago was making sample app for internal ble device. Check bluetooth/gatt package, was really useful such implementation.(project isn't good for production, but as sample/demo is pretty nice)
I want to make an app (or service) that always looks for beacons every minute. If it finds one, it shall start an intentService and upload coordinates to my server.
I have looked at examples in the altbeacon documentation and they are indeed working. However, I am not able to tweak it the way I want.
The best example I found was how to start an app in the background. Here I can set the interval time, scan time, and it is doing what it should - except it only announces new beacons (didEnterRegion method).
There is also an example that continuously scans for beacons (Getting Ranging Updates from Nearby Beacons With Telemetry), but I have not been able to control the interval and scan time (even though it says it is configurable). Also, I must make sure that this will always run, and never goes into some kind of sleepmode.
Lastly, I have tried to mix all of this into my own service using various timer approaches, but I was told by a distant co-worker that the altbeacon library makes a service by itself, and I should not have to.
Does anyone have any tips on how to do this?
Edit
I have used davidgyoung's approach, since the example seems to be pretty much out of the box for me. I will need a few days to test, and get back with an update.
Doing this with the Android Beacon Library is quite straightforward, and you can use the reference app as a starting point.
It is true that you do not need to make your own service, as the library has one of its own. Using the reference app as-is, it starts up automatically on the background and scans for beacons at boot, and will restart itself within five minutes using an AlarmManager even if you kill the app.
Using this approach, simply start ranging in the Application class and process your results in a callback method in that class.
I believe you can use Estimote API for this. Manually you can create service, create instance of BeaconManager if it == null on service or your command started. Add setMonitoringListener and now you can send results from onEnteredRegion.
I'm currently making an app in Android that is checking an API which returns two things. Some text and a colour.
However I want this to be checked for updates every 15 minutes in the background and check every 5 seconds when the app is open. When running in the background it should give a notification if the status is changed.
Now I have checked numerous stackoverflow q&a's and forums, docs etc.. But I can't seem to find a good baseline for what I need. So many documentation that contradicts eachother.. I think that I need an Alarm Manager or a Service... but what do you guys suggest for my problem? The app may not harm the battery too much.
What I really would like to have is that the application doesn't have to "poll" the server every 15 minutes but that the application gets interrupted like.. "hey, there is a new status update". I can't imagine that messaging apps are constantly polling a server for updates? I haven't found much information about that topic... Any help is appreciated. Not asking for code but directions to get where I want to go.
Many thanks
If you're looking to poll the server every X seconds/minutes, AlarmManager(android guide, tutorial) is exactly what you need. However, as you point out this is probably not the best way to go about things. While the app is open you may want to look in to passing messages between the device and server via an open Web Socket. Once your app is closed you could, instead of the app polling the server, have the server push a notification, via GCM or some such, to the app when an update is available.
If you are doing both the server side project and the mobile application, You can use Any messaging service rather than polling for the server, Because there has to be a pusher implementation from the server side to push the status to the MS.
For now GMS is free, I hope it will remain the same :). Otherwise, You can use AlarmManager and IntentService to achieve your goal.
I have an application that i have developed for ios, android and windows phone 8. The client now requires that the application checks if there is any data to be uploaded to the server every 15-30 minutes and if so, upload it. This is needed because the application is used in areas where there will not be an internet connection. The user adds data into the application and that data needs to be uploaded to the server once an internet connection is available
I have implemented this on android using the AlarmManager to schedule the application to check if there is any data and upload it, and on windows phone i used a PeriodicTask.
Is there such functionality in iOS? When i try googling this, i get many different things appear like NSURLSession, Background Transfer Service and others that say it ain't possible.
So, it is possible and what classes do i need to look into to get this working? If i have to aim at a particular iOS version then that is fine.
You can use NSTimer:
[NSTimer scheduledTimerWithTimeInterval: 1800.0 target:self selector:#selector(yourselector) userInfo:nil repeats: YES];
Apple documentation
No, this is not possible, well may be. Since only specific apps can run in the background like: AudioStreamer, VOIP, Accessory companion or location tracking.
These apps can't really schedule a task. Also it would be really bad for the battery to check some server every 15-30 min.
You can use NSURLSessions to create an uploading task that will run on the background.
You will have to setup the session correctly with all the delegate methods implemented: Background Transfer Considerations.
There are mainly 3 things to consider:
1.) Will the app remain active (visible on the device screen) for 15-20 mins. I suppose that won't be the case.
2.) When the app enters background state (not visible on the app screen, but is in the background), you can perform/schedule tasks for a maximum of 3 minutes.
3.) If the user kills the app (the app is not in background mode) then you cannot do anything.
NSTimer *yourTimer = [NSTimer scheduledTimerWithTimeInterval: 1800.0 target:self selector:#selector(YourMethod) userInfo:nil repeats: YES];
please try this ... this will work...
The upload task supports background operations by default (refer : https://developer.apple.com/reference/foundation/urlsessionuploadtask).
But that is limited to as long as the app is in memory. This is to ensure no app consumes battery without absolute NEED.
What you can do is upload in the background mode and check for pending upload data every time you launch your app.