DCA7201: Mobile Application Development - Unit 14 Flashcards

Vocabulary flashcards covering Android sensors, camera APIs, Wi-Fi connectivity, and resource management based on the DCA7201 Unit 14 transcript.

Motion Sensors

A category of sensors that measure acceleration, angular velocity, and orientation, including the accelerometer, gyroscope, rotation vector sensor, and step counter.

Environmental Sensors

Sensors that measure ambient conditions like temperature, pressure, light intensity, and air moisture levels.

Position Sensors

Sensors that provide spatial orientation and geomagnetic data, such as magnetometers and proximity sensors.

Accelerometer

A sensor that detects changes in velocity and gravitational force.

Gyroscope

A sensor that measures rotation around device axes in terms of angular velocity.

Magnetometer

A sensor that measures magnetic fields primarily for compass functionality.

Proximity Sensor

A sensor used to detect the presence or absence of nearby objects.

SensorManager

The primary Android interface for accessing and managing device sensors, allowing developers to query supported sensors and register listeners.

SensorEvent

An object containing a sensor's data payload, including its values, accuracy, and timestamp.

SensorEventListener

An interface implemented by applications to receive real-time sensor updates through callbacks such as onSensorChanged and onAccuracyChanged.

Shake Detection Formula

A formula used to calculate total acceleration: $\text{acceleration} = \text{Math.sqrt}(x \times x + y \times y + z \times z)$, where acceleration greater than $15$ typically triggers an event.

Sensor Fusion

The process of combining data from multiple sensors to produce more accurate and reliable information than any single sensor could provide.

Complementary Filter

A sensor fusion technique that combines high-frequency data from the gyroscope with low-frequency data from the accelerometer.

Kalman Filter

A sensor fusion technique that uses statistical estimation to weigh sensor inputs and reduce noise for better accuracy.

SENSOR_DELAY_FASTEST

The sampling rate constant that provides the maximum update frequency but at the highest power cost.

Camera2 API

A low-level interface that provides fine-grained control over camera hardware, including manual focus, exposure settings, and raw capture formats.

CameraX API

A high-level abstraction built on top of Camera2 that simplifies camera operations and automatically handles device compatibility and lifecycle management.

EXIF (Exchangeable Image File Format)

Metadata embedded in image files containing details such as capture date/time, GPS location, device model, and camera settings.

MediaStore

A system-managed collection on Android that facilitates indexing, searching, and sharing of media files throughout the device.

WifiManager

An API providing direct access to Wi-Fi hardware functions, such as scanning for networks, retrieving signal strength, and configuring connections.

ConnectivityManager

A high-level abstraction for monitoring the overall network state, including Wi-Fi, cellular, and Ethernet connections.

WifiP2pManager

The API used to manage Wi-Fi Direct peer-to-peer discovery, group formation, and data transfer.

Dangerous Permissions

Android permissions that can access sensitive data, such as CAMERA or ACCESS_FINE_LOCATION, requiring explicit user consent at runtime.

WorkManager

A power management API used to schedule deferred tasks optimally to reduce battery consumption.