zephyr/include/drivers/sensor/ccs811.h

163 lines
4.3 KiB
C

/*
* Copyright (c) 2018 Peter Bigot Consulting, LLC
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Extended public API for CCS811 Indoor Air Quality Sensor
*
* Some capabilities and operational requirements for this sensor
* cannot be expressed within the sensor driver abstraction.
*/
#ifndef ZEPHYR_INCLUDE_DRIVERS_SENSOR_CCS811_H_
#define ZEPHYR_INCLUDE_DRIVERS_SENSOR_CCS811_H_
#ifdef __cplusplus
extern "C" {
#endif
#include <device.h>
#include <drivers/sensor.h>
/* Status register fields */
#define CCS811_STATUS_ERROR BIT(0)
#define CCS811_STATUS_DATA_READY BIT(3)
#define CCS811_STATUS_APP_VALID BIT(4)
#define CCS811_STATUS_FW_MODE BIT(7)
/* Error register fields */
#define CCS811_ERROR_WRITE_REG_INVALID BIT(0)
#define CCS811_ERROR_READ_REG_INVALID BIT(1)
#define CCS811_ERROR_MEASMODE_INVALID BIT(2)
#define CCS811_ERROR_MAX_RESISTANCE BIT(3)
#define CCS811_ERROR_HEATER_FAULT BIT(4)
#define CCS811_ERROR_HEATER_SUPPLY BIT(5)
/* Measurement mode constants */
#define CCS811_MODE_IDLE 0x00
#define CCS811_MODE_IAQ_1SEC 0x10
#define CCS811_MODE_IAQ_10SEC 0x20
#define CCS811_MODE_IAQ_60SEC 0x30
#define CCS811_MODE_IAQ_250MSEC 0x40
#define CCS811_MODE_MSK 0x70
/** @brief Information collected from the sensor on each fetch. */
struct ccs811_result_type {
/** Equivalent carbon dioxide in parts-per-million volume (ppmv). */
u16_t co2;
/**
* Equivalent total volatile organic compounts in
* parts-per-billion volume.
*/
u16_t voc;
/** Raw voltage and current measured by sensor. */
u16_t raw;
/** Sensor status at completion of most recent fetch. */
u8_t status;
/**
* Sensor error flags at completion of most recent fetch.
*
* Note that errors are cleared when read.
*/
u8_t error;
};
/**
* @brief Access storage for the most recent data read from the sensor.
*
* This content of the object referenced is updated by
* sensor_fetch_sample(), except for ccs811_result_type::mode which is
* set on driver initialization.
*
* @param dev Pointer to the sensor device
*
* @return a pointer to the result information.
*/
const struct ccs811_result_type *ccs811_result(struct device *dev);
/**
* @brief Get information about static CCS811 state.
*
* This includes the configured operating mode as well as hardware and
* firmware versions.
*/
struct ccs811_configver_type {
u16_t fw_boot_version;
u16_t fw_app_version;
u8_t hw_version;
u8_t mode;
};
/**
* @brief Fetch operating mode and version information.
*
* @param dev Pointer to the sensor device
*
* @param ptr Pointer to where the returned information should be stored
*
* @return 0 on success, or a negative errno code on failure.
*/
int ccs811_configver_fetch(struct device *dev,
struct ccs811_configver_type *ptr);
/**
* @brief Fetch the current value of the BASELINE register.
*
* The BASELINE register encodes data used to correct sensor readings
* based on individual device configuration and variation over time.
*
* For proper management of the BASELINE register see AN000370
* "Baseline Save and Restore on CCS811".
*
* @param dev Pointer to the sensor device
*
* @return a non-negative 16-bit register value, or a negative errno
* code on failure.
*/
int ccs811_baseline_fetch(struct device *dev);
/**
* @brief Update the BASELINE register.
*
* For proper management of the BASELINE register see AN000370
* "Baseline Save and Restore on CCS811".
*
* @param dev Pointer to the sensor device
*
* @param baseline the value to be stored in the BASELINE register.
*
* @return 0 if successful, negative errno code if failure.
*/
int ccs811_baseline_update(struct device *dev, u16_t baseline);
/**
* @brief Update the ENV_DATA register.
*
* Accurate calculation of gas levels requires accurate environment
* data. Measurements are only accurate to 0.5 Cel and 0.5 %RH.
*
* @param dev Pointer to the sensor device
*
* @param temperature the current temperature at the sensor
*
* @param humidity the current humidity at the sensor
*
* @return 0 if successful, negative errno code if failure.
*/
int ccs811_envdata_update(struct device *dev,
const struct sensor_value *temperature,
const struct sensor_value *humidity);
#ifdef __cplusplus
}
#endif
#endif /* ZEPHYR_INCLUDE_DRIVERS_SENSOR_CCS811_H_ */