CCS811 - Gas Sensor

Description

Driver for the Cambridge CMOS Sensors CCS811 gas and indoor air quality sensor.


CCS811 usage example code

Basic example for initializing measuring equivalent Co2 and TVOC level. 

#include "sl_i2cspm_instances.h"
#include "sl_ccs811.h"

int main( void )
{

  ...

  // Initialize sensor and set measure mode
  sl_ccs811_init(sl_i2cspm_sensor_gas);
  sl_ccs811_set_measure_mode(sl_i2cspm_sensor_gas, CCS811_MEASURE_MODE_DRIVE_MODE_1SEC);

  uint16_t eco2;
  uint16_t tvoc;

  while (true) {

    if ( sl_ccs811_is_data_available(sl_i2cspm_sensor_gas) ) {
      sl_ccs811_get_measurement(sl_i2cspm_sensor_gas, &eco2, &tvoc);
    }

    ...

  }

}

Modules

CCS881 - Gas Sensor Details
CCS881 register interface.

Functions

sl_status_t sl_ccs811_init (sl_i2cspm_t *i2cspm)
Initialize the chip.
sl_status_t sl_ccs811_deinit (sl_i2cspm_t *i2cspm)
De-initialize the chip.
sl_status_t sl_ccs811_get_hardware_id (sl_i2cspm_t *i2cspm, uint8_t *hwID)
Reads Hardware ID from the CCS811 sensor.
sl_status_t sl_ccs811_set_measure_mode (sl_i2cspm_t *i2cspm, uint8_t measMode)
Set the measurement mode of the CCS811 sensor.
sl_status_t sl_ccs811_update_firmware (sl_i2cspm_t *i2cspm, const uint8_t *firmware, uint32_t length)
Perform a firmware update of the CCS811 sensor.
sl_status_t sl_ccs811_read_firmware_version (sl_i2cspm_t *i2cspm, uint16_t *fw_version)
Read out current firmware of the CCS811 sensor.
sl_status_t sl_ccs811_get_status (sl_i2cspm_t *i2cspm, uint8_t *status)
Read the status of the CCS811 sensor.
sl_status_t sl_ccs811_read_mailbox (sl_i2cspm_t *i2cspm, uint8_t id, uint8_t length, uint8_t *data)
Read data from a specific Mailbox address.
sl_status_t sl_ccs811_start_application (sl_i2cspm_t *i2cspm)
Switch the CCS811 chip from boot to application mode.
sl_status_t sl_ccs811_software_reset (sl_i2cspm_t *i2cspm)
Perform software reset on the CCS811.
bool sl_ccs811_is_data_available (sl_i2cspm_t *i2cspm)
Check whether new measurement data is available.
sl_status_t sl_ccs811_get_measurement (sl_i2cspm_t *i2cspm, uint16_t *eco2, uint16_t *tvoc)
Read measurement data (eCO2 and TVOC) from the CCS811 sensor.
sl_status_t sl_ccs811_get_raw_data (sl_i2cspm_t *i2cspm, uint16_t *current, uint16_t *rawData)
Get the latest readings from the sense resistor of the CCS811 sensor.
sl_status_t sl_ccs811_set_env_data (sl_i2cspm_t *i2cspm, int32_t tempData, uint32_t rhData)
Write temperature and humidity values to the environmental data regs.

Function Documentation

◆ sl_ccs811_init()

sl_status_t sl_ccs811_init ( sl_i2cspm_t * i2cspm )

Initialize the chip.

Parameters
[in] i2cspm The I2CSPM instance to use.
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_INITIALIZATION Initialization was unsuccessful

◆ sl_ccs811_deinit()

sl_status_t sl_ccs811_deinit ( sl_i2cspm_t * i2cspm )

De-initialize the chip.

Parameters
[in] i2cspm The I2CSPM instance to use.
Returns
Return values
SL_STATUS_OK Success

◆ sl_ccs811_get_hardware_id()

sl_status_t sl_ccs811_get_hardware_id ( sl_i2cspm_t * i2cspm,
uint8_t * hwID
)

Reads Hardware ID from the CCS811 sensor.

Parameters
[in] i2cspm The I2CSPM instance to use.
[out] hwID The Hardware ID of the chip (should be 0x81)
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission error

◆ sl_ccs811_set_measure_mode()

sl_status_t sl_ccs811_set_measure_mode ( sl_i2cspm_t * i2cspm,
uint8_t measMode
)

Set the measurement mode of the CCS811 sensor.

This function must be called before reading measurements from the sensor.

Parameters
[in] i2cspm The I2CSPM instance to use.
[in] measMode The desired measurement mode
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission error

◆ sl_ccs811_update_firmware()

sl_status_t sl_ccs811_update_firmware ( sl_i2cspm_t * i2cspm,
const uint8_t * firmware,
uint32_t length
)

Perform a firmware update of the CCS811 sensor.

This function overwrites the existing firmware, irrespective of the version number.

Parameters
[in] i2cspm The I2CSPM instance to use.
[in] firmware A buffer containing the contents of the firmware update
[in] length The length of the firmware update array
Returns
Return values
SL_STATUS_OK Firmware upgrade successful
SL_STATUS_FAIL Firmware upgrade failed

◆ sl_ccs811_read_firmware_version()

sl_status_t sl_ccs811_read_firmware_version ( sl_i2cspm_t * i2cspm,
uint16_t * fw_version
)

Read out current firmware of the CCS811 sensor.

Parameters
[in] i2cspm The i2cspm instance to use
[out] fw_version The current application firmware. The top 4 bits contain the major firmware version, the next 4 bits contain the minor and the last 8 bits contain the patch version.
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission error

◆ sl_ccs811_get_status()

sl_status_t sl_ccs811_get_status ( sl_i2cspm_t * i2cspm,
uint8_t * status
)

Read the status of the CCS811 sensor.

Parameters
[in] i2cspm The I2CSPM instance to use.
[out] status The content of the CCS811 Status Register
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission error

◆ sl_ccs811_read_mailbox()

sl_status_t sl_ccs811_read_mailbox ( sl_i2cspm_t * i2cspm,
uint8_t id,
uint8_t length,
uint8_t * data
)

Read data from a specific Mailbox address.

Parameters
[in] i2cspm The I2CSPM instance to use.
[in] id The address of the Mailbox register
[in] length The number of bytes to read
[out] data The data read from the sensor
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission error

◆ sl_ccs811_start_application()

sl_status_t sl_ccs811_start_application ( sl_i2cspm_t * i2cspm )

Switch the CCS811 chip from boot to application mode.

Parameters
[in] i2cspm The I2CSPM instance to use
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission failure
SL_STATUS_NOT_AVAILABLE Application firmware is not present in the CCS811 device
SL_STATUS_INVALID_STATE Chip firmware did not switch to application mode

◆ sl_ccs811_software_reset()

sl_status_t sl_ccs811_software_reset ( sl_i2cspm_t * i2cspm )

Perform software reset on the CCS811.

Parameters
[in] i2cspm The I2CSPM instance to use
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission error

◆ sl_ccs811_is_data_available()

bool sl_ccs811_is_data_available ( sl_i2cspm_t * i2cspm )

Check whether new measurement data is available.

Parameters
[in] i2cspm The I2CSPM instance to use
Returns
True if new data available, otherwise false

◆ sl_ccs811_get_measurement()

sl_status_t sl_ccs811_get_measurement ( sl_i2cspm_t * i2cspm,
uint16_t * eco2,
uint16_t * tvoc
)

Read measurement data (eCO2 and TVOC) from the CCS811 sensor.

Parameters
[in] i2cspm The I2CSPM instance to use
[out] eco2 The equivalent CO2 level (in ppm) read from the sensor
[out] tvoc The TVOC level (in ppb) read from the sensor
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission error

◆ sl_ccs811_get_raw_data()

sl_status_t sl_ccs811_get_raw_data ( sl_i2cspm_t * i2cspm,
uint16_t * current,
uint16_t * rawData
)

Get the latest readings from the sense resistor of the CCS811 sensor.

Parameters
[in] i2cspm The I2CSPM instance to use
[out] current The value of current through the sensor
[out] rawData The raw ADC reading of the voltage across the sensor with the selected current
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission error

◆ sl_ccs811_set_env_data()

sl_status_t sl_ccs811_set_env_data ( sl_i2cspm_t * i2cspm,
int32_t tempData,
uint32_t rhData
)

Write temperature and humidity values to the environmental data regs.

Parameters
[in] i2cspm The I2CSPM instance to use.
[in] tempData The environmental temperature in milliCelsius
[in] rhData The relative humidity in millipercent
Returns
Return values
SL_STATUS_OK Success
SL_STATUS_TRANSMIT I2C transmission error