AWARE: Significant Motion

This sensor is used to track device significant motion. Also used internally by AWARE if available to save battery when the device is still with high-frequency sensors. SignificantMotionSensor.Observer allows programmers to take actions on detection of a significant motion.

Based of: sensorplatforms/open-sensor-platform/significantmotiondetector.c

Requirements

iOS 13 or later

Installation

You can integrate this framework into your project via Swift Package Manager (SwiftPM) .

SwiftPM

1. Open Package Manager Windows

   • Open Xcode -> Select Menu Bar -> File -> App Package Dependencies...

2. Find the package using the manager

   • Select Search Package URL and type git@github.com:awareframework/com.awareframework.ios.sensor.significantmotion.git

3. Import the package into your target.

4. Import com.awareframework.ios.sensor.significantmotion library into your source code.

import com_awareframework_ios_sensor_significantmotion

Public Functions

SignificantMotionSensor

• init(config:SignificantMotionSensor.Config?): Initializes the significant motion sensor with the optional configuration.
• start(): Starts the significant motion sensor with the optional configuration.
• stop(): Stops the service.

SignificantMotionSensor.Config

Class to hold the configuration of the sensor.

Fields

• sensorObserver: SignificantMotionObserver: Callback for live data updates.
• enabled: Bool: Sensor is enabled or not. (default = false)
• debug: Bool: Enable/disable logging. (default = false)
• label: String: Label for the data. (default = "")
• deviceId: String: Id of the device that will be associated with the events and the sensor. (default = "")
• dbEncryptionKey: String?: Encryption key for the database. (default = nil)
• dbType: DatabaseType: Which db engine to use for saving data. (default = .none)
• dbPath: String: Path of the database. (default = "aware_significantmotion")
• dbHost: String?: Host for syncing the database. (default = nil)

Broadcasts

Fired Broadcasts

• SignificantMotionSensor.ACTION_AWARE_SIGNIFICANT_MOTION_STARTED: fired when there is a significant motion.
• SignificantMotionSensor.ACTION_AWARE_SIGNIFICANT_MOTION_ENDED: fired when the significant motion has ended.

Received Broadcasts

• SignificantMotionSensor.ACTION_AWARE_SIGNIFICANT_MOTION_START: received broadcast to start the sensor.
• SignificantMotionSensor.ACTION_AWARE_SIGNIFICANT_MOTION_STOP: received broadcast to stop the sensor.
• SignificantMotionSensor.ACTION_AWARE_SIGNIFICANT_MOTION_SYNC: received broadcast to send sync attempt to the host.
• SignificantMotionSensor.ACTION_AWARE_SIGNIFICANT_MOTION_SET_LABEL: received broadcast to set the data label. Label is expected in the SignificantMotionSensor.EXTRA_LABEL field of the intent extras.

Data Representations

SignificantMotion Data

Contains the motion changes.

Field	Type	Description
moving	Bool	Indicates that a significant motion was detected or not.
label	String	Customizable label. Useful for data calibration or traceability
deviceId	String	AWARE device UUID
timestamp	Int64	unixtime milliseconds since 1970
timezone	Int	Timezone of the device
os	String	Operating system of the device (ex. ios)
jsonVersion	Int	JSON schema version

Example Usage

    let sensor = SignificantMotionSensor.init(SignificantMotionSensor.Config().apply { config in
        config.sensorObserver = Observer()
        config.debug  = true
    })
    sensor.start()
    sensor.stop()
}

class Observer:SignificantMotionObserver{
    func onSignificantMotionStart() {
        // Your code here...
    }

    func onSignificantMotionEnd() {
        // Your code here...
    }
}

Related Links

• Core Motion | Apple Developer Documentation
• CMMotionManager | Apple Developer Documentation
• CMAccelerometerData | Apple Developer Documentation

Author

Yuuki Nishiyama (The University of Tokyo), nishiyama@csis.u-tokyo.ac.jp

License

Copyright (c) 2025 AWARE Mobile Context Instrumentation Middleware/Framework (http://www.awareframework.com)

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.