CARP Connectivity Sampling Package

This library contains a sampling package for collection of connectivity related measures to work with the carp_mobile_sensing framework. This packages supports sampling of the following Measure types:

• dk.cachet.carp.wifi
• dk.cachet.carp.connectivity
• dk.cachet.carp.bluetooth

See the wiki for further documentation, particularly on available measure types. See the CARP Mobile Sensing App for an example of how to build a mobile sensing app in Flutter.

There is privacy protection of wifi and bluetooth names as part of the default Privacy Schema.

For Flutter plugins for other CARP products, see CARP Mobile Sensing in Flutter.

If you're interested in writing you own sampling packages for CARP, see the description on how to extend CARP on the wiki.

Installing

To use this package, add the following to you pubspc.yaml file. Note that this package only works together with carp_mobile_sensing.

dependencies:
  flutter:
    sdk: flutter
  carp_mobile_sensing: ^latest
  carp_connectivity_package: ^latest
  ...

Android Integration

As explained in the Android Wi-Fi scanning overview, access to wifi information required different permission to be set. For Android >= 10 (API level 29) you need ACCESS_FINE_LOCATION, and ACCESS_COARSE_LOCATION. For Android >=12 (API level 31) be sure that your app has ACCESS_NETWORK_STATE permission.

Add the following to your app's AndroidManifest.xml file located in android/app/src/main:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="<your_package_name>"
    xmlns:tools="http://schemas.android.com/tools">

   ...

    <!-- The following permissions are used in the Connectivity Package -->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

</manifest>

Note that connectivity changes are not communicated to Android apps in the background starting with Android 8 (SDK 26). Hence, connectivity status is only collected when your app is resumed.

iOS Integration

From iOS >= 13 there is no longer access to wifi information. See here for the Flutter description and here for the iOS description.

To enable bluetooth tracking, add these permissions in the Info.plist file located in ios/Runner:

<key>NSBluetoothAlwaysUsageDescription</key>
<string>Bluetooth needed</string>
<key>UIBackgroundModes</key>
  <array>
  <string>bluetooth-central</string>
  <string>bluetooth-peripheral</string>
  <string>external-accessory</string>
  <string>fetch</string>
</array>

Note that on iOS, it is impossible to do a general Bluetooth scan when the screen is off or the app is in background. This will simply result in an empty scan. Hence, bluetooth devices are only collected when the app is in the foreground.

Using it

To use this package, import it into your app together with the carp_mobile_sensing package:

import 'package:carp_core/carp_core.dart';
import 'package:carp_mobile_sensing/carp_mobile_sensing.dart';
import 'package:carp_connectivity_package/connectivity.dart';

Before creating a study and running it, register this package in the SamplingPackageRegistry.

SamplingPackageRegistry().register(ConnectivitySamplingPackage());

Collection of connectivity measures can be added to a study protocol like this.

// Create a study protocol
StudyProtocol protocol = StudyProtocol(
  ownerId: 'owner@dtu.dk',
  name: 'Connectivity Sensing Example',
);

// Define which devices are used for data collection
// In this case, its only this smartphone
Smartphone phone = Smartphone();
protocol.addPrimaryDevice(phone);

// Add an automatic task that immediately starts collecting connectivity,
// nearby bluetooth devices, and wifi information.
protocol.addTaskControl(
    ImmediateTrigger(),
    BackgroundTask(measures: [
      Measure(type: ConnectivitySamplingPackage.CONNECTIVITY),
      Measure(type: ConnectivitySamplingPackage.BLUETOOTH),
      Measure(type: ConnectivitySamplingPackage.WIFI),
    ]),
    phone);