> ## Documentation Index
> Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Sensor and sensor instances

## Sensor and sensor instances

QSH divides the sensor implementation in two logical units: sensor and sensor instance.

* Sensors are producers, consumers, or a combination of producers and consumers of asynchronous data.

  * Each sensor can have one or more sensor instances.
  * Any request to a sensor for data results in the creation of a sensor instance or sharing of an existing sensor instance.

* The sensor creates sensor instances on demand.

  * Sensors manage the lifecycle and configuration of their
    corresponding instances, and send configuration updates and initial state events to their clients.
  * Each sensor instance operates with a specific client configuration.
  * The sensor instance of a physical sensor programs the sensor hardware to operate at required configuration.
  * Vendors must serve all client requests with a minimal number of
    sensor instances.
  * The sensor instance generates and sends a stream of data to all the active clients.

* Many sensors can share and configure a single sensor instance. This mode of operation is typical to a combo driver for hardware
  sensors, such as the following:

  * Accelerometer and gyroscope
  * Proximity and ambient light