driver number: 0x60001

Humidity

Overview

The humidity driver allows a process to read the ambient humidity from a sensor. Humidity is reported in percent at a precision of hundredths of a percent.

Command

  • Command number: 0

    Description: Does the driver exist?

    Argument 1: unused

    Argument 2: unused

    Returns: SUCCESS if it exists, otherwise ENODEVICE

  • Command number: 1

    Description: Initiate a sensor reading. When a reading is ready, a callback will be delivered if the process has subscribed.

    Argument 1: unused

    Argument 2: unused

    Returns: EBUSY if a reading is already pending, ENOMEM if there isn't sufficient grant memory available, or SUCCESS if the sensor reading was initiated successfully.

Subscribe

  • Subscribe number: 0

    Description: Subscribe to humidity readings.

    Callback signature: The callback receives a single argument, the humidity in hundredths of percent.

    Returns: SUCCESS if the subscribe was successful or ENOMEM if the driver failed to allocate memory to store the callback.