zsensor --- Zephyr sensor bindings#

zsensor

The zsensor module contains a class for using sensors with Zephyr.

class Sensor --- sensor control for the Zephyr port#

Use this class to access data from sensors on your board. See Zephyr documentation for sensor usage here: Sensors.

Sensors are defined in the Zephyr devicetree for each board. The quantities that a given sensor can measure are called a sensor channels. Sensors can have multiple channels to represent different axes of one property or different properties a sensor can measure. See Channels below for defined sensor channels. Each channel may have multiple attributes that can be changed and/or queried. See Channel Attributes below for defined sensor channel attributes.

Constructor#

Device names are defined in the devicetree for your board. For example, the device name for the accelerometer in the FRDM-k64f board is "FXOS8700".

Methods#

Sensor.measure()

Obtains a measurement sample from the sensor device using Zephyr sensor_sample_fetch and stores it in an internal driver buffer as a useful value, a pair of (integer part of value, fractional part of value in 1-millionths). Returns none if successful or OSError value if failure.

Sensor.get_float(sensor_channel)

Returns the value of the sensor measurement sample as a float.

Sensor.get_micros(sensor_channel)

Returns the value of the sensor measurement sample in millionths. (Ex. value of (1, 500000) returns as 1500000)

Sensor.get_millis(sensor_channel)

Returns the value of sensor measurement sample in thousandths. (Ex. value of (1, 500000) returns as 1500)

Sensor.get_int(sensor_channel)

Returns only the integer value of the measurement sample. (Ex. value of (1, 500000) returns as 1)

Sensor.attr_set(sensor_channel, channel_attribute, val1, [val2])

Set the given channel's attribute to the given value. val1 may be a float, in which case val2 is not given, or val1 can be used for the value's integer part and val2 for the value's fractional part in millionths.

Returns None if successful, or raises OSError.

Sensor.attr_get_float(sensor_channel, channel_attribute)

Returns the value of the sensor channel's attribute as a float.

Many sensors do not support this or any other of the attr_get methods.

Sensor.attr_get_micros(sensor_channel, channel_attribute)

Returns the value of the sensor channel's attribute in millionths. (Ex. value of (1, 500000) returns as 1500000)

Sensor.attr_get_millis(sensor_channel, channel_attribute)

Returns the value of the sensor channel's attribute in thousandths. (Ex. value of (1, 500000) returns as 1500)

Sensor.attr_get_int(sensor_channel, channel_attribute)

Returns only the integer value of the channel's attribute. (Ex. value of (1, 500000) returns as 1)

Channels#

ACCEL_X

Acceleration on the X axis, in m/s^2.

ACCEL_Y

Acceleration on the Y axis, in m/s^2.

ACCEL_Z

Acceleration on the Z axis, in m/s^2.

ACCEL_XYZ

Pseudo-channel representing all three accelerometer axes. Used for Sensor.attr_set and the Sensor.attr_get_xxx() methods.

GYRO_X

Angular velocity around the X axis, in radians/s.

GYRO_Y

Angular velocity around the Y axis, in radians/s.

GYRO_Z

Angular velocity around the Z axis, in radians/s.

GYRO_XYZ

Pseudo-channel representing all three gyroscope axes. Used for Sensor.attr_set and the Sensor.attr_get_xxx() methods.

MAGN_X

Magnetic field on the X axis, in Gauss.

MAGN_Y

Magnetic field on the Y axis, in Gauss.

MAGN_Z

Magnetic field on the Z axis, in Gauss.

DIE_TEMP

Device die temperature in degrees Celsius.

PRESS

Pressure in kilopascal.

PROX

Proximity. Dimensionless. A value of 1 indicates that an object is close.

HUMIDITY

Humidity, in percent.

LIGHT

Illuminance in visible spectrum, in lux.

ALTITUDE

Altitude, in meters.

Channel Attributes#

ATTR_SAMPLING_FREQUENCY

Sensor sampling frequency, i.e. how many times a second the sensor takes a measurement.

ATTR_LOWER_THRESH

Lower threshold for trigger.

ATTR_UPPER_THRESH

Upper threshold for trigger.

ATTR_SLOPE_TH

Threshold for any-motion (slope) trigger.

ATTR_SLOPE_DUR

Duration for which the slope values needs to be outside the threshold for the trigger to fire.

ATTR_HYSTERESIS

ATTR_OVERSAMPLING

Oversampling factor.

ATTR_FULL_SCALE

Sensor range, in SI units.

ATTR_OFFSET

The sensor value returned will be altered by the amount indicated by offset: final_value = sensor_value + offset.

ATTR_CALIB_TARGET

Calibration target. This will be used by the internal chip's algorithms to calibrate itself on a certain axis, or all of them.

ATTR_CONFIGURATION

Configure the operating modes of a sensor.

ATTR_CALIBRATION

Set a calibration value needed by a sensor.

ATTR_FEATURE_MASK

Enable/disable sensor features.

ATTR_ALERT

Alert threshold or alert enable/disable.

ATTR_FF_DUR

Free-fall duration represented in milliseconds. If the sampling frequency is changed during runtime, this attribute should be set to adjust freefall duration to the new sampling frequency.

ATTR_BATCH_DURATION

Hardware batch duration in ticks.

ATTR_GAIN

ATTR_RESOLUTION