Sensor Attributes

.. _sensor-attribute:

Sensor Attributes #################

:dfn:Attributes, enumerated in :c:enum:sensor_attribute, are immutable and mutable properties of a sensor and its channels.

Attributes allow for obtaining metadata and changing configuration of a sensor. Common configuration parameters like channel scale, sampling frequency, adjusting channel offsets, signal filtering, power modes, on chip buffers, and event handling options are very common. Attributes provide a flexible API for inspecting and manipulating such device properties.

Attributes are specified using :c:enum:sensor_attribute which can be used with :c:func:sensor_attr_get and :c:func:sensor_attr_set to get and set a sensors attributes.

A quick example...

.. code-block:: c

const struct device *accel_dev = DEVICE_DT_GET(DT_ALIAS(accel0)); struct sensor_value accel_sample_rate; int rc;

rc = sensor_attr_get(accel_dev, SENSOR_CHAN_ACCEL_XYZ, SENSOR_ATTR_SAMPLING_FREQUENCY, &accel_sample_rate); if (rc != 0) { printk("Failed to get sampling frequency\n"); }

printk("Sample rate for accel %p is %d.06%d\n", accel_dev, accel_sample_rate.val1, accel_sample_rate.val2*1000000);

accel_sample_rate.val1 = 2000;

rc = sensor_attr_set(accel_dev, SENSOR_CHAN_ACCEL_XYZ, SENSOR_ATTR_SAMPLING_FREQUENCY, accel_sample_rate); if (rc != 0) { printk("Failed to set sampling frequency\n"); }