Quickstart

Build an app that connects a Movisens sensor by its name and prints tap markers and skin temperature.

The finished app connects to a Movisens sensor by its Bluetooth name and prints each tap marker and skin temperature measurement as JSON.

Prerequisites

The setup in Installation, including the CARP Mobile Sensing (CAMS) setup it builds on.
A Movisens Move4, EcgMove4 or EdaMove4 sensor, and its Bluetooth name: MOVISENS Sensor followed by the five-digit serial number on the back of the sensor.
An Android phone with Bluetooth turned on, and the sensor paired with the phone in the Android Bluetooth settings. On iOS, and for a sensor that is not paired, the status never becomes connected; see the known issue in Connect to the sensor.

Complete example

Replace the contents of lib/main.dart with this program, and set deviceName to the Bluetooth name of your sensor:

lib/main.dart

import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:carp_core/carp_core.dart' hide Smartphone;
import 'package:carp_mobile_sensing/carp_mobile_sensing.dart';
import 'package:carp_movisens_package/carp_movisens_package.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  CarpMobileSensing.ensureInitialized();

  // 1. Register the sampling package
  SamplingPackageRegistry().register(MovisensSamplingPackage());

  // 2. Create a protocol with the phone and a Movisens sensor
  final protocol = SmartphoneStudyProtocol(
    ownerId: 'owner@example.com',
    name: 'Tap markers and skin temperature from a Movisens sensor',
    dataEndPoint: SQLiteDataEndPoint(),
  );
  final phone = Smartphone();
  final movisens = MovisensDevice( 
    sensorLocation: SensorLocation.Chest,
    sex: Sex.Female,
    height: 168, // cm
    weight: 62, // kg
    age: 34,
  );
  protocol
    ..addPrimaryDevice(phone)
    ..addConnectedDevice(movisens, phone);

  // 3. Collect tap markers and skin temperature while the sensor is connected
  protocol.addTaskControl(
    ImmediateTrigger(),
    BackgroundTask(
      measures: [
        Measure(type: MovisensSamplingPackage.TAP_MARKER),
        Measure(type: MovisensSamplingPackage.SKIN_TEMPERATURE),
      ],
    ),
    movisens,
  );

  // 4. Deploy the protocol on the first run and start sampling
  final client = SmartPhoneClientManager();
  await client.configure();
  if (client.studies.isEmpty) {
    final study = await client.addStudyFromProtocol(protocol);
    await client.tryDeployment(study.studyDeploymentId, study.deviceRoleName);
  }
  client.resume();

  // 5. Print each measurement as JSON
  client.measurements.listen((measurement) => print(jsonEncode(measurement)));

  // 6. Bind the sensor by its name, ask for permissions and connect to it
  final manager = client.deviceController.getDeviceManager(
    MovisensDevice.DEVICE_TYPE,
  ) as MovisensDeviceManager;
  manager.statusEvents.listen((status) => print('Movisens: ${status.name}'));
  manager.deviceName = 'MOVISENS Sensor 03348';
  await manager.requestPermissions();
  await manager.connect();

  runApp(
    const MaterialApp(
      home: Scaffold(body: Center(child: Text('Collecting data'))),
    ),
  );
}

How it works

Stage	What it does
1. Register	Makes the Movisens measure types and the sensor known to CAMS. `CarpMobileSensing.ensureInitialized()` runs first, because registering needs an initialized CAMS.
2. Protocol	Adds a `MovisensDevice` with the wearer's sensor location, sex, height, weight and age. The sensor uses these values for its activity algorithms, such as the metabolic equivalent of task (MET) and body position.
3. Task	Runs `TAP_MARKER` and `SKIN_TEMPERATURE` on the sensor. Both are event-based measures, so an `ImmediateTrigger` starts them and they stream while the sensor is connected.
4. Deploy	Configures CAMS, deploys the protocol on the phone and resumes sampling. The sensor's task waits until the sensor connects. The app adds the study only on the first run: on later runs, `configure()` restores the saved study.
5. Print	Prints every measurement as JSON.
6. Connect	Prints each new status of the sensor, binds the sensor by its Bluetooth name, asks for the Bluetooth permissions and connects to it.

Tap markers arrive as soon as you tap the sensor, so they show quickly whether the connection works.

Run the app

Start the app on your phone
flutter run
Allow the nearby devices and location permissions. The console shows Movisens: connected and then Movisens: connecting again, as the known issue in Connect to the sensor describes.

Tap the sensor

A tap marker measurement appears at once:

{
  "sensorStartTime": 1793006600123456,
  "data": {
    "__type": "dk.cachet.carp.movisens.tap_marker",
    "timestamp": "2026-10-26T10:23:20.123456",
    "deviceId": "88:6B:0F:3A:52:C1",
    "type": "tapMarker",
    "tapMarker": 1203
  }
}

Skin temperature arrives about once per minute, up to 84 seconds after the sensor measured it. Both timestamps are the phone's time when the value arrived: timestamp in local time and sensorStartTime in microseconds since the epoch.

To work with the values in code, check the type of the data:

client.measurements.listen((measurement) {
  final data = measurement.data;
  if (data is MovisensSkinTemperature) {
    print('Skin temperature: ${data.skinTemperature} °C');
  }
});

For all the fields, see Measure types.

Troubleshooting

The console never shows connected

Run the app on an Android phone, and pair the sensor with the phone in the Android Bluetooth settings first. When movisens_flutter has to scan for the sensor, the status does not become connected, and no data arrives. See the known issue in Connect to the sensor.

The status changes to disconnected right after connect()

On Android, check that the manifest declares ACCESS_COARSE_LOCATION and that the nearby devices and location permissions are allowed. See Installation.

No skin temperature arrives

Wait 2 minutes: values other than tap markers arrive up to 84 seconds after the sensor measured them. If none arrive, check that your sensor sends skin temperature; see Supported models.

Next steps

Connecting a device

Bind a sensor by its name, connect it and follow its status.

Measure types

The six measure types, their data types, fields and timing.

Triggers

Start tasks on a schedule or when an event occurs.