lecture 6 - 1 - Location maps and sensors.pdf

CSIT242Mobile Application Development LECTURE 6 - 1 – LOCATION MAPS AND SENSORS 1 CSIT242 - SIM 2024 Lecture Plan 1. Android – Location & Google Map API 2. Android supported sensors 3. iOS – Location & Maps 4. iOS supported sensors 2 CSIT242 - SIM 2024 Android – Requesting Runtime Permissions The pu...

CSIT242Mobile Application Development LECTURE 6 - 1 – LOCATION MAPS AND SENSORS 1 CSIT242 - SIM 2024 Lecture Plan 1. Android – Location & Google Map API 2. Android supported sensors 3. iOS – Location & Maps 4. iOS supported sensors 2 CSIT242 - SIM 2024 Android – Requesting Runtime Permissions The purpose of a permission is to protect the privacy of an Android user Android apps must request permission to access sensitive user data (such as contacts and SMS), as well as certain system features (such as camera and internet) Depending on the feature, the system might grant the permission automatically (install-time permissions) or might prompt the user to approve the request (runtime permissions) 3 CSIT242 - SIM 2024 https://developer.android.com/guide/topics/permissions/overview#normal Android – Requesting Runtime Permissions Install-time permissions - give limited access to restricted data or restricted data or resources with very little risk to the user's privacy or the operation of other apps app store presents an install-time permission notice to the user in app's details page automatically granted at install time Normal permissions - access to data and actions that extend beyond your app's sandbox Signature permissions - grants permission to an app only when the app is signed by the same certificate as the app or the OS that defines the permission Run-time (Dangerous) permissions - the app wants data or resources that involve the user's sensitive information, or could potentially affect the operation of other apps The user has to explicitly grant the permission to the app The app must prompt the user to grant permission at runtime These permissions can be revoked later on Special permissions Permission groups - consist of a set of logically related permissions 4 CSIT242 - SIM 2024 Android – Requesting Runtime Permissions Request App permissions declare that the app needs a permission by putting element in the app manifest file check whether the permission is granted (before performing an operation that requires that permission) – use ContextCompat.checkSelfPermission(…) method Provide an explanation if the user has already denied that permission request (shouldShowRequestPermissionRationale() returns true/false if the user has previously denied the request and/or selected the “Don't ask again option”) Request permission - use requestPermissions(…) method When the user responds to the app's permission request, the system invokes the app's onRequestPermissionsResult(…) method 5 CSIT242 - SIM 2024 Geocoding and Reverse-geocoding Latitude and Longitude are the units that represent the coordinates at geographic coordinate system, so we can specify virtually any point on earth Just like every actual house has its address (which includes the number, the name of the street, city, etc), every single point on the surface of earth can be specified by the latitude and longitude coordinates Geocoding (forward-geocoding) is the process of converting a textual based geographical location (such as a street address) into geographical coordinates expressed in terms of longitude and latitude Reverse-geocoding involves the translation of geographical coordinates into a human readable address string Northfields Ave, Wollongong, NSW 2522 6 CSIT242 - SIM 2024 latitude: -34.405404 longitude: 150.878430 Android – Location & Context Location and maps-based apps offer a compelling experience on mobile devices Applications that have “location-related” features are using the classes of the android.location package, Google Location Services API, or the Google Maps Android API Main component of the location framework (android.location package) is the LocationManager system service, which provides APIs to determine location and bearing of the underlying device (if available) The Google Location Services API, part of Google Play services, is the preferred API a simpler API, higher accuracy, automated location tracking, low-power geofencing, and activity recognition new features such as activity detection that are not available in the location framework API 7 CSIT242 - SIM 2024 Android – Location permissions Apps that use location services must request location permissions Android offers three location permissions: ACCESS_COARSE_LOCATION ACCESS_FINE_LOCATION ACCESS_BACKGROUND_LOCATION (on Android 10+ / API level 29+) Chosen permission determines the accuracy of the location returned by the API or access on the device location while the app is in the background... If the app targets Android 10 or higher, must be declared the ACCESS_BACKGROUND_LOCATION permission in the app's manifest file and receive user permission in order to receive regular location updates while the app is in the background. If the app doesn't require location access while running in the background, it's highly recommended not to request ACCESS_BACKGROUND_LOCATION. 8 CSIT242 - SIM 2024 Android – Getting the Last Known Location Using the Google Play services location APIs, the app can request the last known location of the user's device The fused location provider (location APIs in Google Play services) can be used for retrieving the device’s last known location Fused Location Provider manages the underlying location technology and provides a simple API so can be specified requirements at a high level (like high accuracy or low power) optimizes the device's use of battery power 9 CSIT242 - SIM 2024 Android – Getting the Last Known Location To get the last known location of the device, an instance of the Fused Location Provider Client needs to be created The getLastLocation() method can be used to retrieve the device location The precision of the location returned by this call is determined by the permission setting in the app manifest The getLastLocation() method returns a Task that can be used to get a Location object with the latitude and longitude coordinates of a geographic location fusedLocationClient.getLastLocation().addOnSuccessListener(this, new OnSuccessListener() { @Override public void onSuccess(Location location) { //Got last known location. In some situations this can be null. if (location != null) { // Logic to handle location object } } }); 10 CSIT242 - SIM 2024 Android – Getting the Last Known Location The location object may be null in the following situations: Location is turned off in the device settings (disabling location also clears the cache) The device never recorded its location (new device or restoring to factory settings) Google Play services on the device has restarted - there is no active Fused Location Provider client that has requested location after the services restarted The applications that use location, besides the geographical location (latitude and longitude), may require to get: the bearing (horizontal direction of travel), altitude, or velocity of the device These information are also available in the Location object (retrieved from the fused location provider) 11 CSIT242 - SIM 2024 Android – Change Location Settings LocationRequest objects are used to request a quality of service for location updates from the FusedLocationProvider API LocationRequest include methods like: ◦ setIntervalMillis(long) - sets the interval (milliseconds) for location updates ◦ setMinUpdateIntervalMillis(long) – sets the minimal interval of location updates ◦ setPriority(int) - sets the priority of the request: ◦ Priority.PRIORITY_BALANCED_POWER_ACCURACY - request for location precision is balanced between location accuracy and power usage ◦ Priority.PRIORITY_HIGH_ACCURACY – request for the most precise location possible ◦ Priority.PRIORITY_LOW_POWER - request that favours low power usage at the possible expense of location accuracy Priority.PRIORITY_PASSIVE - ensures that no extra power will be used to derive locations (will only receive locations calculated on behalf of other clients) 12 CSIT242 - SIM 2024 Android – Receiving Location Updates Regular location updates can be started by calling requestLocationUpdates() Based on the form of the request, the fused location provider can invoke the LocationCallback.onLocationResult() callback method and passes it a list of Location objects, or issues a PendingIntent that contains the location in its extended data The location updates can be stopped when the activity is no longer in focus This will reduce power consumption To stop location updates, can be called removeLocationUpdates() method 13 CSIT242 - SIM 2024 Android – Displaying a Location Address To get the location from the address and address from location Geocoder class (from android.location package) can be used The getFromLocation() method - accepts a latitude and longitude, and returns a list of addresses The getFromLocationName() method – accept the name of a place ("Wollongong", " Wollongong, Australia”, "Northfields Avenue, Wollongong, Australia",…) and returns an array of Addresses that are known to describe the named location The returned address object will be localized for the locale (specific geographical, political, or cultural region), and can be used to extract the latitude and longitude of the address 14 CSIT242 - SIM 2024 Android – Google Maps Android API The Google Maps Android API allows the inclusion of maps and customized mapping information in the app Using Google Maps Android API maps can be embedded into an activity as a fragment with a simple XML snippet Key developer features 3D maps; indoor, satellite, terrain, and hybrid maps; vector-based tiles for efficient caching and drawing; animated transitions add markers onto the map to indicate special points of interest for the users; define custom colours or icons for the map markers draw polylines and polygons to indicate paths or regions; provide complete image overlays ability to control the rotation, tilt, zoom, and pan properties of the "camera" perspective of the map add Street View to the app 15 CSIT242 - SIM 2024 Android – Google Maps Android API Maps, add to the app with the Google Maps Android API, are based on Google Maps data The API automatically handles access to Google Maps servers, data downloading, map display, and touch gestures on the map The key class in the Google Maps Android API is MapView. A MapView displays a map with data obtained from the Google Maps service MapView advantages provides all of the UI elements necessary for users to control the map captures keypresses and touch gestures to pan and zoom the map automatically the app can also use MapView class methods to control the map programmatically and draw a number of overlays on top of the map can handle network requests for additional maps tiles 16 CSIT242 - SIM 2024 Android – Sensors Most Android-powered devices have built-in sensors that measure motion, orientation, and various environmental conditions These sensors are capable of providing raw data with high precision and accuracy, and are useful for monitoring three-dimensional device movement or positioning, or changes in the ambient environment near a device For example, a game might track readings from a device's gravity sensor to infer complex user gestures and motions, such as tilt, shake, rotation, or swing A weather application might use a device's temperature sensor and humidity sensor to calculate and report the dewpoint 17 CSIT242 - SIM 2024 Android – Sensors The Android platform supports three broad categories of sensors: Motion, Position and Environmental Motion sensors This category includes accelerometers, gravity sensors, gyroscopes, and rotational vector sensors Motion sensors are useful for monitoring device movement, such as tilt, shake, rotation, or swing These sensors measure acceleration forces and rotational forces along three axes The movement is usually a reflection of direct user input (monitoring motion relative to the device's frame of reference or the application's frame of reference), or a reflection of the physical environment in which the device is sitting (monitoring motion relative to the world's frame of reference) 18 CSIT242 - SIM 2024 Android – Sensors Position sensors This category includes orientation sensors and magnetometers Geomagnetic field sensor and the accelerometer sensors measure the physical position of a device (in the world's frame of reference) The Android platform also provides a sensor that determines how close the face of a device is to an object (proximity sensor) Environmental sensors This category includes barometers, photometers, and thermometers These sensors measure various environmental parameters, such as ambient air temperature and pressure, illumination, and humidity With the exception of the light sensor, which most device manufacturers use to control screen brightness, environment sensors are not always available on devices 19 CSIT242 - SIM 2024 Android – Sensors Some of the sensors are hardware-based and some are software-based Hardware-based sensors are physical components built into a handset or tablet device They derive their data by directly measuring specific environmental properties, such as acceleration, geomagnetic field strength, or angular change Software-based sensors are not physical components, although they mimic hardware-based sensors They derive their data from one or more of the hardware-based sensors and are sometimes called virtual sensors or synthetic sensors The orientation sensor type is examples of software-based sensors Depending on the device some sensors can be both hardware of software based, or the device can have more than one sensor of a given type For example gravity sensor can be hardware or software based; also, a device can have two gravity sensors, each one having a different range 20 CSIT242 - SIM 2024 Android – Sensors Android sensor framework (part of android.hardware package) allows access to the sensors (available on the device) and raw sensor data The sensor framework provides several classes and interfaces for performing a wide variety of sensor-related tasks like: Determine which sensors are available on a device Determine an individual sensor's capabilities, such as its maximum range, manufacturer, power requirements, and resolution Acquire raw sensor data and define the minimum rate at which you acquire sensor data Register and unregister sensor event listeners that monitor sensor changes Sensor availability varies from device to device, but it can also vary between Android versions. 21 CSIT242 - SIM 2024 Android – Sensors The sensor framework is part of the android.hardware package and includes the following classes and interfaces: SensorManager – used to create an instance of the sensor service It provides various methods for accessing and listing sensors, registering and unregistering sensor event listeners, acquiring orientation information, and several sensor constants used to report sensor accuracy, set data acquisition rates, and calibrate sensors Sensor - used to create an instance of a specific sensor It provides various methods that let you determine a sensor's capabilities SensorEvent – used to create a sensor event object A sensor event object includes the raw sensor data, the type of sensor that generated the event, the accuracy of the data, and the timestamp for the event SensorEventListener - interface used to create two callback methods that receive notifications (sensor events) when sensor values change or when sensor accuracy changes 22 CSIT242 - SIM 2024 Android – Sensors Android does not specify a standard sensor configuration for devices Device manufacturers can incorporate any sensor configuration that they want into their Android-powered devices devices can include a variety of sensors in a wide range of configurations There are two options for ensuring that a given sensor is present on a device: Detect sensors at runtime and enable or disable application features as appropriate Use Google Play filters to target devices with specific sensor configurations 23 CSIT242 - SIM 2024 Android – Sensors Useful notes for creating apps that use sensors: Always verify that a sensor exists on a device before you attempt to acquire data from it Be sure to unregister a sensor's listener when you are done using the sensor or when the sensor activity pauses If a sensor listener is registered and its activity is paused, the sensor will continue to acquire data and use battery resources unless you unregister the sensor Be sure to choose a delivery rate that is suitable for the application or use-case Sensors can provide data at very high rates, so sending extra data wastes system resources and uses battery power Sensor data can change at a high rate, which means the system may call the onSensorChanged(SensorEvent) method quite often - do as little as possible within the onSensorChanged(SensorEvent) method (don't block it!) 24 CSIT242 - SIM 2024 iOS – Location & Maps For a while Apple relied on a competitor (Google) for mapping data in iOS; This dependency officially ended with iOS 6 through the introduction of Apple Maps In iOS 8, Apple Maps officially replaced the Google-based map data with data provided primarily by a company named TomTom (but also including technology from other companies, including some acquired by Apple for this purpose) Apps use location data for many purposes, ranging from social networking to turn-by-turn navigation services 25 CSIT242 - SIM 2024 iOS – Location & Maps Location-based information (in the app) consists of two pieces: location services, and maps Location services are provided by the Core Location framework, and obtain information about the user’s location and heading (the direction in which a device is pointing) Maps are provided by the Map Kit framework, which supports both the display and annotation of maps 26 CSIT242 - SIM 2024 iOS – Getting the User’s Location Core Location framework provides several services that can be used to get and monitor the device’s current location uses all available onboard hardware, including Wi-Fi, GPS, Bluetooth, magnetometer, barometer, and cellular hardware to gather data provides services for determining a device’s geographic location, altitude, orientation, or position relative to a nearby iBeacon standard location service - offers a highly configurable way to get the current location and track changes (for the specified level of accuracy) significant-change location service - provides a way to get the current location and be notified when significant changes occur - delivers updates only when there has been a significant change (500 meters or more) in the device’s location region monitoring - lets monitoring boundary crossings for defined geographical regions and Bluetooth low-energy beacon regions 27 CSIT242 - SIM 2024 iOS – Getting the User’s Location For iOS app that requires location services include the UIRequiredDeviceCapabilities key in the app’s Info.plist identifying the required features with strings: location-services – require location services in general gps – requires the accuracy offered only by GPS hardware App Store will not allow downloading the app if the device doesn’t contain the listed features The app that uses Core Location must requests the user’s permission for location services by: including the Privacy-Location When In Use Description (NSLocationWhenInUseUsageDescription) or Privacy-Location Always and When In Use Usage Description (NSLocationAlwaysUsageDescription) key in its Info.plist file (using a string that describes how the app intends to use location data) 28 CSIT242 - SIM 2024 iOS – Getting the User’s Location To use the location service, an instance of the CLLocationManager class should be created Using the location manager object: set the delegate for the location manager check if the location services are available (use locationServicesEnabled() method) requestWhenInUseAuthorization() or requestAlwaysAuthorization() method should be called before the app can receive location-related information can be configured the desiredAccuracy and distanceFilter start receiving location notifications by calling the startUpdatingLocation() or startMonitoringSignificantLocationChanges() methods stop the delivery of location updates by calling the stopUpdatingLocation() or stopMonitoringSignificantLocationChanges() methods When the location data become available, the location manager reports events to/call the locationManager(_:didUpdateLocations:) method of its delegate 29 CSIT242 - SIM 2024 iOS – Getting the Heading and Course of a Device Core Location supports two different ways to get direction-related information: Devices with a magnetometer can report the direction in which a device is pointing, also known as its heading Devices with GPS hardware can report the direction in which a device is moving, also known as its course Heading and course information don’t represent the same information The heading of a device reflects the actual orientation of the device relative to true north or magnetic north The course of the device represents the direction of travel and doesn’t take into account the device orientation 30 CSIT242 - SIM 2024 iOS – Geocoding Location Data To initiate a forward or reverse-geocoding request the CLGeocoder class can be used A geocoder object uses a network service to convert between latitude and longitude values and a placemark (collection of data such as the street, city, state, and country information) Reverse geocoding is supported in all versions of iOS, but forward geocoding is supported only in iOS 5.0 and later Geocoders rely on a network service - a live network connection must be present in order for a geocoding request to succeed If a device is in Airplane mode or the network is currently not configured - the geocoder can’t connect to the service it needs, so it will return an appropriate error 31 CSIT242 - SIM 2024 iOS – Geocoding Location Data For forward geocoding, the geocoder object parses the given information - if it finds a match returns a number of placemark objects The more information provided to the forward geocoder, the better the results returned The number of returned placemark objects depends greatly on the specificity of the provided information The geocoder object initiates the reverse geocoding request asynchronously and delivers the results to the provided (completition handler) block The block is executed regardless of whether the request succeeds or fails The same CLGeocoder object can be used to initiate any number of geocoding requests but only one request at a time may be active for a given geocoder 32 CSIT242 - SIM 2024 iOS – Displaying Maps The Map Kit framework allows embedding a fully functional map interface into the app A map can be displayed as: Standard Satellite Hybrid Map Kit supports three basic coordinate systems for specifying map data points: A map coordinate - a latitude and longitude on the spherical representation of the Earth (CLLocationCoordinate2D structure, or specifing areas using the MKCoordinateSpan and MKCoordinateRegion structures) A map point - an x and y value on the Mercator map projection (MKMapPoint structure, or specify areas using the MKMapSize and MKMapRect structures) A point - a graphical unit associated with the coordinate system of a view object (CGPoint structure, or specify areas using the CGSize and CGRect structures) 33 CSIT242 - SIM 2024 iOS – Displaying Maps The MKMapView class is a self-contained interface for presenting map data in the app It provides support for displaying map data, managing user interactions, and hosting custom content provided by your app A map view is a view - it can be manipulated the same way as other views change its size and position, configure its autoresizing behaviors, add subviews A delegate object should be assigned to the map view The map view reports all relevant interactions to its delegate, so the delegate can respond appropriately The MKMapView class has several properties that can be configured programmatically which part of the map is currently visible, whether the content is displayed in 3D, what user interactions are allowed The region property of the MKMapView class controls the currently visible portion of the map Displaying the user’s current location on the map can be done by setting the showsUserLocation property of the map view object it causes the map view to use Core Location to find the user’s location and add an annotation to the map 34 CSIT242 - SIM 2024 iOS – Annotating Maps Annotations display content that can be defined by a single coordinate point The annotations can represent information such as the user’s current location, a specific address, or a single point of interest Overlays display content that is defined by any number of points and may constitute one or more contiguous or noncontiguous shapes The overlays can present more complex information such as routes or traffic information, or the boundaries of areas such as parks, lakes, cities, states, or countries Map Kit separates the data associated with an annotation or overlay from its visual presentation on the map This separation allows the map to manage visible annotations and overlays much more efficiently 35 CSIT242 - SIM 2024 iOS – Annotating Maps Annotation objects are typically small data objects that store the map coordinate data and any other relevant information about the annotation, such as a title string The map view keeps a reference to the annotation objects you add to it and uses the data in those objects to determine when to display the corresponding view To display an annotation on a map, two distinct objects must be provided: An annotation object, which is an object that conforms to the MKAnnotation protocol and manages the data for the annotation An annotation view, which is a view (derived from the MKAnnotationView class) used to draw the visual representation of the annotation on the map surface Map Kit provides some standard annotation objects – MKPointAnnotation class can be used displaying a title string at the specified point on the map The annotations you create are typically anchored to a single map coordinate that doesn’t change, but you can modify an annotation’s coordinate programmatically if needed. In addition, you can implement support to allow users to drag annotations around the map. 36 CSIT242 - SIM 2024 iOS – Annotating Maps Overlays offer a way to layer content over an arbitrary region of the map Overlays are typically defined by multiple coordinates You can use these coordinates to create contiguous or noncontiguous sets of lines, rectangles, circles, and other shapes, which can then be filled or stroked with colour To display an overlay on a map, the app must provide two distinct objects: An overlay object, which is an object that conforms to the MKOverlay protocol and manages the data points for the overlay An overlay renderer (derived from MKOverlayRenderer) used to draw the visual representation of the overlay on the map surface 37 CSIT242 - SIM 2024 iOS – Annotating Maps Overlay objects are generally small data objects that store the points that define the overlay and any other relevant information, such as a title string Map Kit defines several concrete overlay objects (for specifying different types of standard shapes) and standard overlay renderers (that can draw any shapes represented by the concrete overlay objects) The standard overlay classes include MKCircle, MKPolygon, and MKPolyline 38 CSIT242 - SIM 2024 iOS – Providing Directions Map Kit includes the MKDirections API, which provides route-based directions data from Apple servers MKDirections API provide step-by-step walking or driving directions, travel time estimates, alternate routes, and other information Using Map Kit support for map-based directions, an app can: Ask the Maps app to display directions to the user Register as a routing app and provide point-to-point, turn-based directions to Maps and other apps on the user’s device Get general-purpose directions information An app that is able to display point-to-point directions can register as a routing app and make those directions available to the Maps app and to all other apps on a user’s device. 39 CSIT242 - SIM 2024 iOS – Enabling Search Map Kit provides the MKLocalSearch API to support searches based on user-entered queries Apps can use this API to perform searches for locations that users describe by name, address, or type, such as coffee or theatre Although local search and geocoding are similar, they support different use cases: Use geocoding when you want to convert between map coordinates and a structured address, such as an Address Book address Use local search when you want to find a set of locations that match the user’s input 40 CSIT242 - SIM 2024 iOS – Sensors A device need to contain hardware for sensing the world around itself — where it is located, how it is oriented, how it is moving Core Location framework provides information about the device’s current location and how that location is changing overtime, along with information about the device’s orientation relative to north UIEvent class (for device shake) and the Core Motion framework provide information about the device’s change in speed and attitude The device may have an extra chip that analyzes and records the user’s activity, such as walking or running - the Core Motion framework provides access to this information 41 CSIT242 - SIM 2024 iOS – Sensors One of the major challenges associated with applications that uses sensor data is that different devices have different hardware (type of sensors) The app should provide a subset of its full capabilities when it discovers that the current device lacks certain features certain sensors may experience momentary inadequacy, or some sensors take time to “warm up,” so that the values you’ll get from them initially will be invalid All sensor usage means battery usage (sometimes to a considerably greater degree) 42 CSIT242 - SIM 2024 iOS – Sensors The Core Location framework provides facilities for the device to determine and report its location and device orientation using sensors: Wi-Fi - may scan for nearby Wi-Fi devices and compare these against an online database Cell - may compare nearby telephone cell towers against an online database GPS - may be able to obtain a position fix (information) from GPS satellites – it is the most accurate location sensor, but it takes the longest to get a fix, and in some situations it can fail Magnetometer – provide information about the device’s orientation relative to north Core Location will automatically use whatever facilities the device has available It allows to specify how accurate a position fix needs to be - more accurate fixes may require more time The notion of a location is encapsulated by the CLLocation class with properties: coordinate (latitude and longitude), altitude, speed, course, horizontalAccuracy and timestamp 43 CSIT242 - SIM 2024 iOS – Sensors Core Motion framework reports motion and environment-related data from the onboard hardware (including accelerometers, gyroscopes, pedometer, magnetometer and barometer) This framework allows access to hardware-generated data that can be used in the app For example, a game might use accelerometer and gyroscope data to control onscreen game behaviour Many services of this framework allow access to the raw values recorded by the hardware and a processed version of those values Processed values do not include forms of bias that might adversely affect how you use that data For example, a processed accelerometer value reflects only the acceleration caused by the user and not the acceleration caused by gravity 44 CSIT242 - SIM 2024 iOS – Sensors Acceleration is detected through the device’s accelerometer, supplemented by the gyroscope (if there is one) The accelerometer always has something to measure (because of the gravity) - thus the device can report its attitude relative to the vertical Acceleration information can arrive in two ways: As a prepackaged UIEvent – as notification of a predefined gesture performed by accelerating the device using the Core Motion framework an instance of CMMotionManager allows obtaining accelerometer information, gyroscope information, or device motion information (Core Motion can be also used to get magnetometer information). 45 CSIT242 - SIM 2024 iOS – Sensors The inclusion of an electronic gyroscope in the hardware of some devices makes a huge difference in the accuracy and speed of gravity and attitude reporting A gyroscope has the property that its attitude in space remains constant; thus it can detect any change in the attitude of the containing device The advantages include: The accelerometer can be supplemented by the gyroscope to detect quickly the difference between gravity and user-induced acceleration The gyroscope can observe pure rotation, where little or no acceleration is involved (case where the accelerometer is helpful – cannot detect) The extreme case is constant attitudinal rotation around the gravity axis, which the accelerometer alone would be completely unable to detect 46 CSIT242 - SIM 2024 iOS – Sensors Core Motion package up the calculated combination of accelerometer and gyroscope data in a CMDeviceMotion instance Class CMDeviceMotion properties include: gravity, userAcceleration, rotationRate, magneticField, attitude and heading Some devices have a motion coprocessor chip that can detect, analyze, and keep a record of device motion (even while the device is asleep and with very little battery power) It is an analysis of the device’s physical motion and attitude in order to draw conclusions about what the user has been doing while carrying or wearing the device This is not a form of location determination – the data recorded that the user is walking, or walked for an hour, but not where the user was walking Interaction with the motion coprocessor is through an instance of a CMMotionActivityManager class 47 CSIT242 - SIM 2024 Resources Android Studio Dolphin Essentials - Java Edition, Neil Smyth, Payload Media Inc., 2022. Programming iOS 14 - Dive Deep into Views, View Controllers, and Frameworks, Matt Neuburg, O'Reilly Media Inc., 2021 iOS 12 App Development Essentials, Neil Smyth, Payload Media, Inc., 2018. https://developer.android.com/guide/topics/permissions/overview#normal https://developer.android.com/training/location/index.html https://developer.android.com/guide/topics/sensors/sensors_overview https://developer.apple.com/library/content/documentation/UserExperience/Conceptual/Loc ationAwarenessPG/Introduction/Introduction.html If you need to setup Google Play services and add the library to your project https://developers.google.com/android/guides/setup https://developers.google.com/maps/documentation/android-api/start 48 CSIT242 - SIM 2024