Detailed Description

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

Functions
uint32_t	CCS811_deInit (void)
	De-initializes the chip.

void	CCS811_dumpRegisters (void)
	Dumps the registers of the CSS811.

uint32_t	CCS811_getHardwareID (uint8_t *hardwareID)
	Reads Hardware ID from the CSS811 sensor.

uint32_t	CCS811_getMeasurement (uint16_t eco2, uint16_t tvoc)
	Reads measurement data (eCO2 and TVOC) from the CSS811 sensor.

uint32_t	CCS811_getRawData (uint16_t current, uint16_t rawData)
	Gets the latest readings from the sense resistor of the CSS811 sensor.

uint32_t	CCS811_getStatus (uint8_t *status)
	Reads the status of the CSS811 sensor.

uint32_t	CCS811_init (void)
	Initializes the chip and performs firmware upgrade if required.

bool	CCS811_isDataAvailable (void)
	Checks if new measurement data available.

uint32_t	CCS811_readMailbox (uint8_t id, uint8_t length, uint8_t *data)
	Reads data from a specific Mailbox address.

uint32_t	CCS811_setEnvData (int32_t tempData, uint32_t rhData)
	Writes temperature and humidity values to the environmental data regs.

uint32_t	CCS811_setMeasureMode (uint8_t measMode)
	Sets the measurement mode of the CSS811 sensor.

uint32_t	CCS811_softwareReset (void)
	Performs software reset on the CCS811.

uint32_t	CCS811_startApplication (void)
	Switches the CSS811 chip from boot to application mode.

Error Codes
#define	CCS811_OK 0x0000

#define	CCS811_ERROR_APPLICATION_NOT_PRESENT 0x0001

#define	CCS811_ERROR_NOT_IN_APPLICATION_MODE 0x0002

#define	CCS811_ERROR_DRIVER_NOT_INITIALIZED 0x0003

#define	CCS811_ERROR_I2C_TRANSACTION_FAILED 0x0004

#define	CCS811_ERROR_INIT_FAILED 0x0005

#define	CCS811_ERROR_FIRMWARE_UPDATE_FAILED 0x0006

Register Addresses
#define	CCS811_ADDR_STATUS 0x00

#define	CCS811_ADDR_MEASURE_MODE 0x01

#define	CCS811_ADDR_ALG_RESULT_DATA 0x02

#define	CCS811_ADDR_RAW_DATA 0x03

#define	CCS811_ADDR_ENV_DATA 0x05

#define	CCS811_ADDR_NTC 0x06

#define	CCS811_ADDR_THRESHOLDS 0x10

#define	CCS811_ADDR_HW_ID 0x20

#define	CCS811_ADDR_HW_VERSION 0x21

#define	CCS811_ADDR_FW_BOOT_VERSION 0x23

#define	CCS811_ADDR_FW_APP_VERSION 0x24

#define	CCS811_ADDR_ERR_ID 0xE0

#define	CCS811_ADDR_FW_ERASE 0xF1

#define	CCS811_ADDR_FW_PROGRAM 0xF2

#define	CCS811_ADDR_FW_VERIFY 0xF3

#define	CCS811_ADDR_APP_START 0xF4

#define	CCS811_ADDR_SW_RESET 0xFF

Measure mode value definitions
#define	CCS811_MEASURE_MODE_DRIVE_MODE_SHIFT 4

#define	CCS811_MEASURE_MODE_DRIVE_MODE_IDLE 0x00

#define	CCS811_MEASURE_MODE_DRIVE_MODE_1SEC 0x10

#define	CCS811_MEASURE_MODE_DRIVE_MODE_10SEC 0x20

#define	CCS811_MEASURE_MODE_DRIVE_MODE_60SEC 0x30

#define	CCS811_MEASURE_MODE_DRIVE_MODE_RAW 0x40

#define	CCS811_MEASURE_MODE_INTERRUPT 0x08

#define	CCS811_MEASURE_MODE_THRESH 0x04

Macro Definition Documentation

#define CCS811_ADDR_ALG_RESULT_DATA 0x02

Algorithm result

Definition at line 55 of file ccs811.h .

Referenced by CCS811_dumpRegisters() , and CCS811_getMeasurement() .

#define CCS811_ADDR_APP_START 0xF4

Application start

Definition at line 68 of file ccs811.h .

#define CCS811_ADDR_ENV_DATA 0x05

Temperature and Humidity data can be written to enable compensation

Definition at line 57 of file ccs811.h .

Referenced by CCS811_dumpRegisters() , and CCS811_setEnvData() .

#define CCS811_ADDR_ERR_ID 0xE0

Error ID

Definition at line 64 of file ccs811.h .

Referenced by CCS811_dumpRegisters() .

#define CCS811_ADDR_FW_APP_VERSION 0x24

Firmware Application Version

Definition at line 63 of file ccs811.h .

Referenced by CCS811_dumpRegisters() .

#define CCS811_ADDR_FW_BOOT_VERSION 0x23

Firmware Boot Version

Definition at line 62 of file ccs811.h .

Referenced by CCS811_dumpRegisters() .

#define CCS811_ADDR_FW_ERASE 0xF1

Firmware erase

Definition at line 65 of file ccs811.h .

#define CCS811_ADDR_FW_PROGRAM 0xF2

Firmware programming

Definition at line 66 of file ccs811.h .

#define CCS811_ADDR_FW_VERIFY 0xF3

Firmware verification

Definition at line 67 of file ccs811.h .

#define CCS811_ADDR_HW_ID 0x20

Hardware ID

Definition at line 60 of file ccs811.h .

Referenced by CCS811_dumpRegisters() , and CCS811_getHardwareID() .

#define CCS811_ADDR_HW_VERSION 0x21

Hardware Version

Definition at line 61 of file ccs811.h .

Referenced by CCS811_dumpRegisters() .

#define CCS811_ADDR_MEASURE_MODE 0x01

Measurement mode and conditions register

Definition at line 54 of file ccs811.h .

Referenced by CCS811_dumpRegisters() , and CCS811_setMeasureMode() .

#define CCS811_ADDR_NTC 0x06

Provides the voltage across the reference resistor and the voltage across the NTC resistor

Definition at line 58 of file ccs811.h .

Referenced by CCS811_dumpRegisters() .

#define CCS811_ADDR_RAW_DATA 0x03

Raw ADC data values for resistance and current source used

Definition at line 56 of file ccs811.h .

Referenced by CCS811_dumpRegisters() , and CCS811_getRawData() .

#define CCS811_ADDR_STATUS 0x00

Status register

Definition at line 53 of file ccs811.h .

Referenced by CCS811_dumpRegisters() , CCS811_getStatus() , and CCS811_startApplication() .

#define CCS811_ADDR_SW_RESET 0xFF

Software reset

Definition at line 69 of file ccs811.h .

Referenced by CCS811_softwareReset() .

#define CCS811_ADDR_THRESHOLDS 0x10

Thresholds for operation when interrupts are only generated when eCO2 ppm crosses a threshold

Definition at line 59 of file ccs811.h .

Referenced by CCS811_dumpRegisters() .

#define CCS811_ERROR_APPLICATION_NOT_PRESENT 0x0001

Application firmware is not present

Definition at line 41 of file ccs811.h .

Referenced by CCS811_startApplication() .

#define CCS811_ERROR_DRIVER_NOT_INITIALIZED 0x0003

The driver is not initialized

Definition at line 43 of file ccs811.h .

#define CCS811_ERROR_FIRMWARE_UPDATE_FAILED 0x0006

The firmware update was unsuccessful

Definition at line 46 of file ccs811.h .

#define CCS811_ERROR_I2C_TRANSACTION_FAILED 0x0004

I2C transaction failed

Definition at line 44 of file ccs811.h .

Referenced by CCS811_getMeasurement() , CCS811_getRawData() , CCS811_readMailbox() , CCS811_setEnvData() , CCS811_setMeasureMode() , and CCS811_softwareReset() .

#define CCS811_ERROR_INIT_FAILED 0x0005

The initialization failed

Definition at line 45 of file ccs811.h .

Referenced by CCS811_init() .

#define CCS811_ERROR_NOT_IN_APPLICATION_MODE 0x0002

The part is not in application mode

Definition at line 42 of file ccs811.h .

Referenced by CCS811_startApplication() .

#define CCS811_MEASURE_MODE_DRIVE_MODE_10SEC 0x20

IAQ Mode 2, a measurement is performed every 10 seconds

Definition at line 79 of file ccs811.h .

#define CCS811_MEASURE_MODE_DRIVE_MODE_1SEC 0x10

IAQ Mode 1, a measurement is performed every second

Definition at line 78 of file ccs811.h .

#define CCS811_MEASURE_MODE_DRIVE_MODE_60SEC 0x30

IAQ Mode 3, a measurement is performed every 60 seconds

Definition at line 80 of file ccs811.h .

#define CCS811_MEASURE_MODE_DRIVE_MODE_IDLE 0x00

Idle mode, measurements are disabled

Definition at line 77 of file ccs811.h .

#define CCS811_MEASURE_MODE_DRIVE_MODE_RAW 0x40

IAQ Mode 4, Raw Data Mode, a measurement is performed every 250ms for external algorithms

Definition at line 81 of file ccs811.h .

#define CCS811_MEASURE_MODE_DRIVE_MODE_SHIFT 4

DRIVE_MODE field bit shift value

Definition at line 76 of file ccs811.h .

#define CCS811_MEASURE_MODE_INTERRUPT 0x08

Interrupt generation enable

Definition at line 82 of file ccs811.h .

#define CCS811_MEASURE_MODE_THRESH 0x04

Enable interrupt when eCO2 level exceeds threshold

Definition at line 83 of file ccs811.h .

#define CCS811_OK 0x0000

No errors

Definition at line 40 of file ccs811.h .

Referenced by CCS811_deInit() , CCS811_getMeasurement() , CCS811_getRawData() , CCS811_init() , CCS811_isDataAvailable() , CCS811_readMailbox() , CCS811_setEnvData() , CCS811_setMeasureMode() , and CCS811_softwareReset() .

Function Documentation

uint32_t CCS811_deInit ( void )

De-initializes the chip.

Returns: Returns zero on OK, non-zero otherwise

Definition at line 100 of file ccs811.c .

References BOARD_gasSensorEnable() , BOARD_gasSensorWake() , and CCS811_OK .

void CCS811_dumpRegisters ( void )

Dumps the registers of the CSS811.

Returns: None

Definition at line 179 of file ccs811.c .

References CCS811_ADDR_ALG_RESULT_DATA , CCS811_ADDR_ENV_DATA , CCS811_ADDR_ERR_ID , CCS811_ADDR_FW_APP_VERSION , CCS811_ADDR_FW_BOOT_VERSION , CCS811_ADDR_HW_ID , CCS811_ADDR_HW_VERSION , CCS811_ADDR_MEASURE_MODE , CCS811_ADDR_NTC , CCS811_ADDR_RAW_DATA , CCS811_ADDR_STATUS , CCS811_ADDR_THRESHOLDS , and CCS811_readMailbox() .

uint32_t CCS811_getHardwareID ( uint8_t * hardwareID )

Reads Hardware ID from the CSS811 sensor.

Parameters

[out] hardwareID The Hardware ID of the chip (should be 0x81)

Returns: Returns zero on OK, non-zero otherwise

Definition at line 119 of file ccs811.c .

References CCS811_ADDR_HW_ID , and CCS811_readMailbox() .

Referenced by CCS811_init() .

uint32_t CCS811_getMeasurement	(	uint16_t *	`eco2,`
		uint16_t *	`tvoc`
	)

Reads measurement data (eCO2 and TVOC) from the CSS811 sensor.

Parameters

[out]	`eco2`	The eCO2 level read from the sensor
[out]	`tvoc`	The TVOC level read from the sensor

Returns: Returns zero on OK, non-zero otherwise

Definition at line 321 of file ccs811.c .

References I2C_TransferSeq_TypeDef::addr , BOARD_gasSensorWake() , BOARD_i2cBusSelect() , I2C_TransferSeq_TypeDef::buf , CCS811_ADDR_ALG_RESULT_DATA , CCS811_ERROR_I2C_TRANSACTION_FAILED , CCS811_OK , I2C_TransferSeq_TypeDef::data , I2C_TransferSeq_TypeDef::flags , I2C_FLAG_WRITE_READ , I2CSPM_Transfer() , i2cTransferDone , and I2C_TransferSeq_TypeDef::len .

uint32_t CCS811_getRawData	(	uint16_t *	`current,`
		uint16_t *	`rawData`
	)

Gets the latest readings from the sense resistor of the CSS811 sensor.

Parameters

[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: Returns zero on OK, non-zero otherwise

Definition at line 376 of file ccs811.c .

References I2C_TransferSeq_TypeDef::addr , BOARD_gasSensorWake() , BOARD_i2cBusSelect() , I2C_TransferSeq_TypeDef::buf , CCS811_ADDR_RAW_DATA , CCS811_ERROR_I2C_TRANSACTION_FAILED , CCS811_OK , I2C_TransferSeq_TypeDef::data , I2C_TransferSeq_TypeDef::flags , I2C_FLAG_WRITE_READ , I2CSPM_Transfer() , i2cTransferDone , and I2C_TransferSeq_TypeDef::len .

uint32_t CCS811_getStatus ( uint8_t * status )

Reads the status of the CSS811 sensor.

Parameters

[out] status The content of the CSS811 Status Register

Returns: Returns zero on OK, non-zero otherwise.

Definition at line 138 of file ccs811.c .

References CCS811_ADDR_STATUS , and CCS811_readMailbox() .

Referenced by CCS811_isDataAvailable() .

uint32_t CCS811_init ( void )

Initializes the chip and performs firmware upgrade if required.

Returns: Returns zero on OK, non-zero otherwise

Definition at line 63 of file ccs811.c .

References BOARD_gasSensorEnable() , BOARD_gasSensorWake() , CCS811_ERROR_INIT_FAILED , CCS811_getHardwareID() , CCS811_OK , and UTIL_delay() .

bool CCS811_isDataAvailable ( void )

Checks if new measurement data available.

Returns: True if new data available, otherwise false

Definition at line 154 of file ccs811.c .

References CCS811_getStatus() , and CCS811_OK .

uint32_t CCS811_readMailbox	(	uint8_t	`id,`
		uint8_t	`length,`
		uint8_t *	`data`
	)

Reads data from a specific Mailbox address.

Parameters

[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: Returns zero on OK, non-zero otherwise

Definition at line 272 of file ccs811.c .

References I2C_TransferSeq_TypeDef::addr , BOARD_gasSensorWake() , BOARD_i2cBusSelect() , I2C_TransferSeq_TypeDef::buf , CCS811_ERROR_I2C_TRANSACTION_FAILED , CCS811_OK , I2C_TransferSeq_TypeDef::data , I2C_TransferSeq_TypeDef::flags , I2C_FLAG_WRITE_READ , I2CSPM_Transfer() , i2cTransferDone , and I2C_TransferSeq_TypeDef::len .

Referenced by CCS811_dumpRegisters() , CCS811_getHardwareID() , CCS811_getStatus() , and CCS811_startApplication() .

uint32_t CCS811_setEnvData	(	int32_t	`tempData,`
		uint32_t	`rhData`
	)

Writes temperature and humidity values to the environmental data regs.

Parameters

[in]	`tempData`	The environmental temperature in milli-Celsius
[in]	`rhData`	The relative humidity in milli-percent

Returns: Returns zero on OK, non-zero otherwise

Definition at line 917 of file ccs811.c .

References I2C_TransferSeq_TypeDef::addr , BOARD_gasSensorWake() , BOARD_i2cBusSelect() , I2C_TransferSeq_TypeDef::buf , CCS811_ADDR_ENV_DATA , CCS811_ERROR_I2C_TRANSACTION_FAILED , CCS811_OK , I2C_TransferSeq_TypeDef::data , I2C_TransferSeq_TypeDef::flags , I2C_FLAG_WRITE , I2CSPM_Transfer() , i2cTransferDone , and I2C_TransferSeq_TypeDef::len .

uint32_t CCS811_setMeasureMode ( uint8_t measMode )

Sets the measurement mode of the CSS811 sensor.

Parameters

[in] measMode The desired measurement mode

Returns: Returns zero on OK, non-zero otherwise

Definition at line 474 of file ccs811.c .

References I2C_TransferSeq_TypeDef::addr , BOARD_gasSensorWake() , BOARD_i2cBusSelect() , I2C_TransferSeq_TypeDef::buf , CCS811_ADDR_MEASURE_MODE , CCS811_ERROR_I2C_TRANSACTION_FAILED , CCS811_OK , I2C_TransferSeq_TypeDef::data , I2C_TransferSeq_TypeDef::flags , I2C_FLAG_WRITE , I2CSPM_Transfer() , i2cTransferDone , and I2C_TransferSeq_TypeDef::len .

uint32_t CCS811_softwareReset ( void )

Performs software reset on the CCS811.

Returns: Returns zero on OK, non-zero otherwise

Definition at line 425 of file ccs811.c .

References I2C_TransferSeq_TypeDef::addr , BOARD_gasSensorWake() , BOARD_i2cBusSelect() , I2C_TransferSeq_TypeDef::buf , CCS811_ADDR_SW_RESET , CCS811_ERROR_I2C_TRANSACTION_FAILED , CCS811_OK , I2C_TransferSeq_TypeDef::data , I2C_TransferSeq_TypeDef::flags , I2C_FLAG_WRITE , I2CSPM_Transfer() , i2cTransferDone , and I2C_TransferSeq_TypeDef::len .

uint32_t CCS811_startApplication ( void )

Switches the CSS811 chip from boot to application mode.

Returns: Returns zero on OK, non-zero otherwise

Definition at line 229 of file ccs811.c .

References CCS811_ADDR_STATUS , CCS811_ERROR_APPLICATION_NOT_PRESENT , CCS811_ERROR_NOT_IN_APPLICATION_MODE , and CCS811_readMailbox() .

CCS811 - Indoor Air Quality SensorBSP > Thunderboard Sense BSP

Detailed Description

Functions

Error Codes

Register Addresses

Measure mode value definitions

Macro Definition Documentation

Function Documentation