Sensor Attributes
Attributes, enumerated in 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 sensor_attribute which can be used with
sensor_attr_get() and sensor_attr_set() to get and set a sensors
attributes.
A quick example…
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");
}