Part 1
요약·해설
Immutable·mutable property와 sensor_attr_get/set 사용법을 설명합니다.
sensor · channel properties
get · set
Part 2
접을 수 있는 영어 원문 전체
영어 원문 전체 펼치기
6165DEE20A059CEFE177F5284DFC3C1D4DB9E2ECF334E94B649C6C08B164F27F
.. _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");
}
Part 3
한국어 전문 번역
sensor_attribute enum에 열거된 attribute는 sensor와 그 channel이 가진 immutable·mutable property입니다.
Attribute를 통해 metadata를 얻고 sensor configuration을 변경할 수 있습니다. Channel scale, sampling frequency, channel offset 조정, signal filtering, power mode, on-chip buffer, event handling option 같은 parameter가 흔한 예입니다. Attribute는 이런 device property를 조사하고 조작하는 유연한 API를 제공합니다.
sensor_attribute로 attribute를 지정하고 sensor_attr_get()과 sensor_attr_set()으로 sensor attribute를 가져오거나 설정합니다.
다음은 accelerometer sampling frequency를 읽고 2000으로 변경하는 간단한 예입니다.
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");
}
Source
출처
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