DocID026411 Rev 2

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AN4503

Document overview

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Figure 1. Android sensor HAL overview

1.1.1

Kernel

This layer contains the Linux device drivers created using the input subsystem, a generic

Linux framework for all input devices. The data are exported to the user space through the

Sysfs virtual file system (/sys/class/input/). The driver sends/receives data to/from the

sensor through the stable Linux subsystem I²C.

1.1.2

Sensor libraries

These libraries are used to create a sophisticated interface for the upper layer. This is

achieved through the sensor manager class, the sensor service class and the sensor HAL.

1.1.3

Application framework

This is the layer that is used by the apk application to obtain data from the sensors.

Communication begins in the SensorManager class, which creates an instance of the

sensor service, and then proceeds to the lower layer through the sensor JNI (Java native

interface).