Added in API level 1

android.hardware

Provides support for hardware features, such as the camera and other sensors. Be aware that not all Android-powered devices support all hardware features, so you should declare hardware that your application requires using the <uses-feature> manifest element.

Interfaces

Camera.AutoFocusCallback This interface was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.AutoFocusMoveCallback This interface was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.ErrorCallback This interface was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.FaceDetectionListener This interface was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.OnZoomChangeListener This interface was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.PictureCallback This interface was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.PreviewCallback This interface was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.ShutterCallback This interface was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
SensorEventListener Used for receiving notifications from the SensorManager when there is new sensor data. 
SensorEventListener2 Used for receiving a notification when a flush() has been successfully completed. 
SensorListener This interface was deprecated in API level 3. Use SensorEventListener instead. 

Classes

BatteryState The BatteryState class is a representation of a single battery on a device. 
Camera This class was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.Area This class was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.CameraInfo This class was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.Face This class was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.Parameters This class was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
Camera.Size This class was deprecated in API level 21. We recommend using the new android.hardware.camera2 API for new applications. 
ConsumerIrManager Class that operates consumer infrared on the device. 
ConsumerIrManager.CarrierFrequencyRange Represents a range of carrier frequencies (inclusive) on which the infrared transmitter can transmit 
DataSpace DataSpace identifies three components of colors - standard (primaries), transfer and range. 
GeomagneticField Estimates magnetic field at a given point on Earth, and in particular, to compute the magnetic declination from true north. 
HardwareBuffer HardwareBuffer wraps a native AHardwareBuffer object, which is a low-level object representing a memory buffer accessible by various hardware units. 
OverlayProperties Provides supported overlay properties of the device. 
Sensor Class representing a sensor. 
SensorAdditionalInfo This class represents a Sensor additional information frame, which is reported through listener callback onSensorAdditionalInfo. 
SensorDirectChannel Class representing a sensor direct channel. 
SensorEvent This class represents a Sensor event and holds information such as the sensor's type, the time-stamp, accuracy and of course the sensor's data. 
SensorEventCallback Used for receiving sensor additional information frames. 
SensorManager

SensorManager lets you access the device's sensors. 

SensorManager.DynamicSensorCallback Used for receiving notifications from the SensorManager when dynamic sensors are connected or disconnected. 
SensorPrivacyManager This class provides information about the microphone and camera toggles. 
SensorPrivacyManager.Sensors Sensor constants which are used in SensorPrivacyManager 
SyncFence A SyncFence represents a synchronization primitive which signals when hardware units have completed work on a particular resource. 
TriggerEvent This class represents a Trigger Event - the event associated with a Trigger Sensor. 
TriggerEventListener This class is the listener used to handle Trigger Sensors.