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/**
* @file sensor.h
*
* @brief Public APIs for the sensor driver.
*/
/*
* Copyright (c) 2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef __SENSOR_H__
#define __SENSOR_H__
/**
* @brief Sensor Interface
* @defgroup sensor_interface Sensor Interface
* @ingroup io_interfaces
* @{
*/
#ifdef __cplusplus
extern "C" {
#endif
#include <zephyr/types.h>
#include <device.h>
#include <errno.h>
/**
* @brief Representation of a sensor readout value.
*
* The value is represented as having an integer and a fractional part,
* and can be obtained using the formula val1 + val2 * 10^(-6). Negative
* values also adhere to the above formula, but may need special attention.
* Here are some examples of the value representation:
*
* 0.5: val1 = 0, val2 = 500000
* -0.5: val1 = 0, val2 = -500000
* -1.0: val1 = -1, val2 = 0
* -1.5: val1 = -1, val2 = -500000
*/
struct sensor_value {
/** Integer part of the value. */
s32_t val1;
/** Fractional part of the value (in one-millionth parts). */
s32_t val2;
};
/**
* @brief Sensor channels.
*/
enum sensor_channel {
/** Acceleration on the X axis, in m/s^2. */
SENSOR_CHAN_ACCEL_X,
/** Acceleration on the Y axis, in m/s^2. */
SENSOR_CHAN_ACCEL_Y,
/** Acceleration on the Z axis, in m/s^2. */
SENSOR_CHAN_ACCEL_Z,
/** Acceleration on the X, Y and Z axes. */
SENSOR_CHAN_ACCEL_XYZ,
/**
* This enum value will be deprecated.
* Please use SENSOR_CHAN_ACCEL_XYZ instead.
*
* Acceleration on any axis.
*/
SENSOR_CHAN_ACCEL_ANY = SENSOR_CHAN_ACCEL_XYZ,
/** Angular velocity around the X axis, in radians/s. */
SENSOR_CHAN_GYRO_X,
/** Angular velocity around the Y axis, in radians/s. */
SENSOR_CHAN_GYRO_Y,
/** Angular velocity around the Z axis, in radians/s. */
SENSOR_CHAN_GYRO_Z,
/** Angular velocity around the X, Y and Z axes. */
SENSOR_CHAN_GYRO_XYZ,
/**
* This enum value will be deprecated.
* Please use SENSOR_CHAN_GYRO_XYZ instead.
*
* Angular velocity on any axis.
*/
SENSOR_CHAN_GYRO_ANY = SENSOR_CHAN_GYRO_XYZ,
/** Magnetic field on the X axis, in Gauss. */
SENSOR_CHAN_MAGN_X,
/** Magnetic field on the Y axis, in Gauss. */
SENSOR_CHAN_MAGN_Y,
/** Magnetic field on the Z axis, in Gauss. */
SENSOR_CHAN_MAGN_Z,
/** Magnetic field on the X, Y and Z axes. */
SENSOR_CHAN_MAGN_XYZ,
/**
* This enum value will be deprecated.
* Please use SENSOR_CHAN_MAGN_XYZ instead.
*
* Magnetic field on any axis.
*/
SENSOR_CHAN_MAGN_ANY = SENSOR_CHAN_MAGN_XYZ,
/** Temperature in degrees Celsius. */
SENSOR_CHAN_TEMP,
/** Pressure in kilopascal. */
SENSOR_CHAN_PRESS,
/**
* Proximity. Adimensional. A value of 1 indicates that an
* object is close.
*/
SENSOR_CHAN_PROX,
/** Humidity, in percent. */
SENSOR_CHAN_HUMIDITY,
/** Illuminance in visible spectrum, in lux. */
SENSOR_CHAN_LIGHT,
/** Illuminance in infra-red spectrum, in lux. */
SENSOR_CHAN_IR,
/** Illuminance in red spectrum, in lux. */
SENSOR_CHAN_RED,
/** Illuminance in green spectrum, in lux. */
SENSOR_CHAN_GREEN,
/** Illuminance in blue spectrum, in lux. */
SENSOR_CHAN_BLUE,
/** Altitude, in meters */
SENSOR_CHAN_ALTITUDE,
/** 1.0 micro-meters Particulate Matter, in ug/m^3 */
SENSOR_CHAN_PM_1_0,
/** 2.5 micro-meters Particulate Matter, in ug/m^3 */
SENSOR_CHAN_PM_2_5,
/** 10 micro-meters Particulate Matter, in ug/m^3 */
SENSOR_CHAN_PM_10,
/** Distance. From sensor to target, in meters */
SENSOR_CHAN_DISTANCE,
/** CO2 level, in parts per million (ppm) **/
SENSOR_CHAN_CO2,
/** VOC level, in parts per billion (ppb) **/
SENSOR_CHAN_VOC,
/** Voltage, in volts **/
SENSOR_CHAN_VOLTAGE,
/** Current, in amps **/
SENSOR_CHAN_CURRENT,
/** All channels. */
SENSOR_CHAN_ALL,
};
/**
* @brief Sensor trigger types.
*/
enum sensor_trigger_type {
/**
* Timer-based trigger, useful when the sensor does not have an
* interrupt line.
*/
SENSOR_TRIG_TIMER,
/** Trigger fires whenever new data is ready. */
SENSOR_TRIG_DATA_READY,
/**
* Trigger fires when the selected channel varies significantly.
* This includes any-motion detection when the channel is
* acceleration or gyro. If detection is based on slope between
* successive channel readings, the slope threshold is configured
* via the @ref SENSOR_ATTR_SLOPE_TH and @ref SENSOR_ATTR_SLOPE_DUR
* attributes.
*/
SENSOR_TRIG_DELTA,
/** Trigger fires when a near/far event is detected. */
SENSOR_TRIG_NEAR_FAR,
/**
* Trigger fires when channel reading transitions configured
* thresholds. The thresholds are configured via the @ref
* SENSOR_ATTR_LOWER_THRESH and @ref SENSOR_ATTR_UPPER_THRESH
* attributes.
*/
SENSOR_TRIG_THRESHOLD,
/** Trigger fires when a single tap is detected. */
SENSOR_TRIG_TAP,
/** Trigger fires when a double tap is detected. */
SENSOR_TRIG_DOUBLE_TAP,
};
/**
* @brief Sensor trigger spec.
*/
struct sensor_trigger {
/** Trigger type. */
enum sensor_trigger_type type;
/** Channel the trigger is set on. */
enum sensor_channel chan;
};
/**
* @brief Sensor attribute types.
*/
enum sensor_attribute {
/**
* Sensor sampling frequency, i.e. how many times a second the
* sensor takes a measurement.
*/
SENSOR_ATTR_SAMPLING_FREQUENCY,
/** Lower threshold for trigger. */
SENSOR_ATTR_LOWER_THRESH,
/** Upper threshold for trigger. */
SENSOR_ATTR_UPPER_THRESH,
/** Threshold for any-motion (slope) trigger. */
SENSOR_ATTR_SLOPE_TH,
/**
* Duration for which the slope values needs to be
* outside the threshold for the trigger to fire.
*/
SENSOR_ATTR_SLOPE_DUR,
/** Oversampling factor */
SENSOR_ATTR_OVERSAMPLING,
/** Sensor range, in SI units. */
SENSOR_ATTR_FULL_SCALE,
/**
* The sensor value returned will be altered by the amount indicated by
* offset: final_value = sensor_value + offset.
*/
SENSOR_ATTR_OFFSET,
/**
* Calibration target. This will be used by the internal chip's
* algorithms to calibrate itself on a certain axis, or all of them.
*/
SENSOR_ATTR_CALIB_TARGET,
};
/**
* @typedef sensor_trigger_handler_t
* @brief Callback API upon firing of a trigger
*
* @param "struct device *dev" Pointer to the sensor device
* @param "struct sensor_trigger *trigger" The trigger
*/
typedef void (*sensor_trigger_handler_t)(struct device *dev,
struct sensor_trigger *trigger);
/**
* @typedef sensor_attr_set_t
* @brief Callback API upon setting a sensor's attributes
*
* See sensor_attr_set() for argument description
*/
typedef int (*sensor_attr_set_t)(struct device *dev,
enum sensor_channel chan,
enum sensor_attribute attr,
const struct sensor_value *val);
/**
* @typedef sensor_trigger_set_t
* @brief Callback API for setting a sensor's trigger and handler
*
* See sensor_trigger_set() for argument description
*/
typedef int (*sensor_trigger_set_t)(struct device *dev,
const struct sensor_trigger *trig,
sensor_trigger_handler_t handler);
/**
* @typedef sensor_sample_fetch_t
* @brief Callback API for fetching data from a sensor
*
* See sensor_sample_fetch() for argument description
*/
typedef int (*sensor_sample_fetch_t)(struct device *dev,
enum sensor_channel chan);
/**
* @typedef sensor_channel_get_t
* @brief Callback API for getting a reading from a sensor
*
* See sensor_channel_get() for argument description
*/
typedef int (*sensor_channel_get_t)(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val);
struct sensor_driver_api {
sensor_attr_set_t attr_set;
sensor_trigger_set_t trigger_set;
sensor_sample_fetch_t sample_fetch;
sensor_channel_get_t channel_get;
};
/**
* @brief Set an attribute for a sensor
*
* @param dev Pointer to the sensor device
* @param chan The channel the attribute belongs to, if any. Some
* attributes may only be set for all channels of a device, depending on
* device capabilities.
* @param attr The attribute to set
* @param val The value to set the attribute to
*
* @return 0 if successful, negative errno code if failure.
*/
__syscall int sensor_attr_set(struct device *dev,
enum sensor_channel chan,
enum sensor_attribute attr,
const struct sensor_value *val);
static inline int _impl_sensor_attr_set(struct device *dev,
enum sensor_channel chan,
enum sensor_attribute attr,
const struct sensor_value *val)
{
const struct sensor_driver_api *api = dev->driver_api;
if (!api->attr_set) {
return -ENOTSUP;
}
return api->attr_set(dev, chan, attr, val);
}
/**
* @brief Activate a sensor's trigger and set the trigger handler
*
* The handler will be called from a thread, so I2C or SPI operations are
* safe. However, the thread's stack is limited and defined by the
* driver. It is currently up to the caller to ensure that the handler
* does not overflow the stack.
*
* This API is not permitted for user threads.
*
* @param dev Pointer to the sensor device
* @param trig The trigger to activate
* @param handler The function that should be called when the trigger
* fires
*
* @return 0 if successful, negative errno code if failure.
*/
static inline int sensor_trigger_set(struct device *dev,
struct sensor_trigger *trig,
sensor_trigger_handler_t handler)
{
const struct sensor_driver_api *api = dev->driver_api;
if (!api->trigger_set) {
return -ENOTSUP;
}
return api->trigger_set(dev, trig, handler);
}
/**
* @brief Fetch a sample from the sensor and store it in an internal
* driver buffer
*
* Read all of a sensor's active channels and, if necessary, perform any
* additional operations necessary to make the values useful. The user
* may then get individual channel values by calling @ref
* sensor_channel_get.
*
* Since the function communicates with the sensor device, it is unsafe
* to call it in an ISR if the device is connected via I2C or SPI.
*
* @param dev Pointer to the sensor device
*
* @return 0 if successful, negative errno code if failure.
*/
__syscall int sensor_sample_fetch(struct device *dev);
static inline int _impl_sensor_sample_fetch(struct device *dev)
{
const struct sensor_driver_api *api = dev->driver_api;
return api->sample_fetch(dev, SENSOR_CHAN_ALL);
}
/**
* @brief Fetch a sample from the sensor and store it in an internal
* driver buffer
*
* Read and compute compensation for one type of sensor data (magnetometer,
* accelerometer, etc). The user may then get individual channel values by
* calling @ref sensor_channel_get.
*
* This is mostly implemented by multi function devices enabling reading at
* different sampling rates.
*
* Since the function communicates with the sensor device, it is unsafe
* to call it in an ISR if the device is connected via I2C or SPI.
*
* @param dev Pointer to the sensor device
* @param type The channel that needs updated
*
* @return 0 if successful, negative errno code if failure.
*/
__syscall int sensor_sample_fetch_chan(struct device *dev,
enum sensor_channel type);
static inline int _impl_sensor_sample_fetch_chan(struct device *dev,
enum sensor_channel type)
{
const struct sensor_driver_api *api = dev->driver_api;
return api->sample_fetch(dev, type);
}
/**
* @brief Get a reading from a sensor device
*
* Return a useful value for a particular channel, from the driver's
* internal data. Before calling this function, a sample must be
* obtained by calling @ref sensor_sample_fetch or
* @ref sensor_sample_fetch_chan. It is guaranteed that two subsequent
* calls of this function for the same channels will yield the same
* value, if @ref sensor_sample_fetch or @ref sensor_sample_fetch_chan
* has not been called in the meantime.
*
* For vectorial data samples you can request all axes in just one call
* by passing the specific channel with _XYZ suffix. The sample will be
* returned at val[0], val[1] and val[2] (X, Y and Z in that order).
*
* @param dev Pointer to the sensor device
* @param chan The channel to read
* @param val Where to store the value
*
* @return 0 if successful, negative errno code if failure.
*/
__syscall int sensor_channel_get(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val);
static inline int _impl_sensor_channel_get(struct device *dev,
enum sensor_channel chan,
struct sensor_value *val)
{
const struct sensor_driver_api *api = dev->driver_api;
return api->channel_get(dev, chan, val);
}
/**
* @brief The value of gravitational constant in micro m/s^2.
*/
#define SENSOR_G 9806650LL
/**
* @brief The value of constant PI in micros.
*/
#define SENSOR_PI 3141592LL
/**
* @brief Helper function to convert acceleration from m/s^2 to Gs
*
* @param ms2 A pointer to a sensor_value struct holding the acceleration,
* in m/s^2.
*
* @return The converted value, in Gs.
*/
static inline s32_t sensor_ms2_to_g(const struct sensor_value *ms2)
{
s64_t micro_ms2 = ms2->val1 * 1000000LL + ms2->val2;
if (micro_ms2 > 0) {
return (micro_ms2 + SENSOR_G / 2) / SENSOR_G;
} else {
return (micro_ms2 - SENSOR_G / 2) / SENSOR_G;
}
}
/**
* @brief Helper function to convert acceleration from Gs to m/s^2
*
* @param g The G value to be converted.
* @param ms2 A pointer to a sensor_value struct, where the result is stored.
*/
static inline void sensor_g_to_ms2(s32_t g, struct sensor_value *ms2)
{
ms2->val1 = ((s64_t)g * SENSOR_G) / 1000000LL;
ms2->val2 = ((s64_t)g * SENSOR_G) % 1000000LL;
}
/**
* @brief Helper function for converting radians to degrees.
*
* @param rad A pointer to a sensor_value struct, holding the value in radians.
*
* @return The converted value, in degrees.
*/
static inline s32_t sensor_rad_to_degrees(const struct sensor_value *rad)
{
s64_t micro_rad_s = rad->val1 * 1000000LL + rad->val2;
if (micro_rad_s > 0) {
return (micro_rad_s * 180LL + SENSOR_PI / 2) / SENSOR_PI;
} else {
return (micro_rad_s * 180LL - SENSOR_PI / 2) / SENSOR_PI;
}
}
/**
* @brief Helper function for converting degrees to radians.
*
* @param d The value (in degrees) to be converted.
* @param rad A pointer to a sensor_value struct, where the result is stored.
*/
static inline void sensor_degrees_to_rad(s32_t d, struct sensor_value *rad)
{
rad->val1 = ((s64_t)d * SENSOR_PI / 180LL) / 1000000LL;
rad->val2 = ((s64_t)d * SENSOR_PI / 180LL) % 1000000LL;
}
/**
* @brief Helper function for converting struct sensor_value to double.
*
* @param val A pointer to a sensor_value struct.
* @return The converted value.
*/
static inline double sensor_value_to_double(struct sensor_value *val)
{
return (double)val->val1 + (double)val->val2 / 1000000;
}
#include <syscalls/sensor.h>
#ifdef __cplusplus
}
#endif
/**
* @}
*/
#endif /* __SENSOR_H__ */