XENSIV™ PAS CO2 sensor ModusToolbox™ interface

General Description

Basic set of APIs for interacting with the XENSIV™ PAS CO2 sensor.

This provides basic initialization and access to the CO2 ppm value. It also provides access to the base XENSIV™ PAS CO2 driver for full control.

Note

XENSIV™ PAS CO2 sensor support requires delays. If the RTOS_AWARE component is set or CY_RTOS_AWARE is defined, the HAL driver will defer to the RTOS for delays. Because of this, make sure that the RTOS scheduler has started before calling any functions.

Code snippets

Snippet 1: Simple initialization with I2C

The following snippet initializes an I2C instance and the XENSIV™ PAS CO2 sensor, and then reads from the XENSIV™ PAS CO2 sensor.

    /* Initialize I2C */
    cyhal_i2c_cfg_t i2c_master_config = {CYHAL_I2C_MODE_MASTER,
                                         0,
                                         I2C_MASTER_FREQUENCY};
 
    cyhal_i2c_t cyhal_i2c;
    result = cyhal_i2c_init(&cyhal_i2c, PIN_XENSIV_PASCO2_I2C_SDA, PIN_XENSIV_PASCO2_I2C_SCL, NULL);
    CY_ASSERT(result == CY_RSLT_SUCCESS);
 
    result = cyhal_i2c_configure(&cyhal_i2c, &i2c_master_config);
    CY_ASSERT(result == CY_RSLT_SUCCESS);
 
    /* Wait until the sensor is ready */
    cyhal_system_delay_ms(WAIT_SENSOR_RDY_MS);
 
    /* Initialize the PAS CO2 sensor with the default parameter values */
    xensiv_pasco2_mtb_t xensiv_pasco2;
    result = xensiv_pasco2_mtb_init_i2c(&xensiv_pasco2, &cyhal_i2c);
    if (result != CY_RSLT_SUCCESS)
    {
        printf("PAS CO2 device initialization error");
        CY_ASSERT(0);
    }
 
    /* Poll PAS CO2 sensor data ready */
    uint16_t ppm;
    do
    {
        cyhal_system_delay_ms(10);
        result = xensiv_pasco2_mtb_read(&xensiv_pasco2, DEFAULT_PRESSURE_REF_HPA, &ppm);
    } while (result != CY_RSLT_SUCCESS);
 
    printf("CO2 %d ppm.\n", ppm);

Snippet 2: XENSIV™ PAS CO2 sensor interrupt configuration

The following snippet demonstrates how to configure a XENSIV™ PAS CO2 sensor interrupt.

    xensiv_pasco2_interrupt_config_t int_config =
    {
        .b.int_func = XENSIV_PASCO2_INTERRUPT_FUNCTION_DRDY,
        .b.int_typ = XENSIV_PASCO2_INTERRUPT_TYPE_LOW_ACTIVE
    };
 
    xensiv_pasco2_mtb_interrupt_cb_t int_cb = 
    {
        .cb = xensiv_pasco2_int_cb,
        .arg = NULL;
    };
 
    result = xensiv_pasco2_mtb_interrupt_init_ex(&xensiv_pasco2, 
                                                 int_config,
                                                 0, 
                                                 PIN_XENSIV_PASCO2_INT,
                                                 CYHAL_ISR_PRIORITY_DEFAULT, 
                                                 &int_cb);
    if (result != CY_RSLT_SUCCESS)
    {
        printf("PAS CO2 interrupt initialization error");
        CY_ASSERT(0);
    }
 
    for (;;)
    {
        if (xensiv_pasco2_drdy)
        {
            printf("XENSIV PAS CO2 interrupt detected\r\n");
            xensiv_pasco2_drdy = false;
            result = xensiv_pasco2_mtb_read(&xensiv_pasco2, DEFAULT_PRESSURE_REF_HPA, &ppm);
 
            if (result != CY_RSLT_SUCCESS)
            {
                printf("XENSIV PAS CO2 read failed\r\n");
            }
            else
            {
                printf("CO2 %d ppm.\n", ppm);
            }
        }
        cyhal_system_delay_ms(10);
    }

Macros
#define	CY_RSLT_MODULE_BOARD_HARDWARE_XENSIV_PASCO2   0x01CA
#define	XENSIV_PASCO2_RSLT_ERR_COMM    (CY_RSLT_CREATE(CY_RSLT_TYPE_ERROR, CY_RSLT_MODULE_BOARD_HARDWARE_XENSIV_PASCO2, XENSIV_PASCO2_ERR_COMM))
	Result code indicating a communication error.
#define	XENSIV_PASCO2_RSLT_ERR_WRITE_TOO_LARGE    (CY_RSLT_CREATE(CY_RSLT_TYPE_ERROR, CY_RSLT_MODULE_BOARD_HARDWARE_XENSIV_PASCO2, XENSIV_PASCO2_ERR_WRITE_TOO_LARGE))
	Result code indicating that an unexpectedly large I2C write was requested which is not supported.
#define	XENSIV_PASCO2_RSLT_ERR_NOT_READY    (CY_RSLT_CREATE(CY_RSLT_TYPE_ERROR, CY_RSLT_MODULE_BOARD_HARDWARE_XENSIV_PASCO2, XENSIV_PASCO2_ERR_NOT_READY))
	Result code indicating that the sensor is not yet ready after reset.
#define	XENSIV_PASCO2_RSLT_ICCERR    (CY_RSLT_CREATE(CY_RSLT_TYPE_ERROR, CY_RSLT_MODULE_BOARD_HARDWARE_XENSIV_PASCO2, XENSIV_PASCO2_ICCERR))
	Result code indicating whether an invalid command has been received by the serial communication interface.
#define	XENSIV_PASCO2_RSLT_ORVS    (CY_RSLT_CREATE(CY_RSLT_TYPE_ERROR, CY_RSLT_MODULE_BOARD_HARDWARE_XENSIV_PASCO2, XENSIV_PASCO2_ORVS))
	Result code indicating whether a condition where VDD12V has been outside the specified valid range has been detected.
#define	XENSIV_PASCO2_RSLT_ORTMP    (CY_RSLT_CREATE(CY_RSLT_TYPE_ERROR, CY_RSLT_MODULE_BOARD_HARDWARE_XENSIV_PASCO2, XENSIV_PASCO2_ORTMP))
	Result code indicating whether a condition where the temperature has been outside the specified valid range has been detected.
#define	XENSIV_PASCO2_RSLT_READ_NRDY    (CY_RSLT_CREATE(CY_RSLT_TYPE_ERROR, CY_RSLT_MODULE_BOARD_HARDWARE_XENSIV_PASCO2, XENSIV_PASCO2_READ_NRDY))
	Result code indicating that a new CO2 value is not yet ready.

Functions
cy_rslt_t	xensiv_pasco2_mtb_init_i2c (xensiv_pasco2_t *dev, cyhal_i2c_t *i2c)
	Initializes the XENSIV™ PAS CO2 sensor and configures it to use the specified I2C peripheral. More...
cy_rslt_t	xensiv_pasco2_mtb_init_uart (xensiv_pasco2_t *dev, cyhal_uart_t *uart)
	Initializes the XENSIV™ PAS CO2 sensor, and configures it to use the specified UART peripheral. More...
cy_rslt_t	xensiv_pasco2_mtb_interrupt_init (const xensiv_pasco2_t *dev, const xensiv_pasco2_interrupt_config_t int_config, uint16_t alarm_threshold, cyhal_gpio_t pin, uint8_t intr_priority, cyhal_gpio_event_callback_t callback, void *callback_arg)
	Configures a GPIO pin as an interrupt for the PAS CO2 sensor. More...
cy_rslt_t	xensiv_pasco2_mtb_interrupt_init_ex (xensiv_pasco2_t *dev, const xensiv_pasco2_interrupt_config_t int_config, uint16_t alarm_threshold, cyhal_gpio_t pin, uint8_t intr_priority, xensiv_pasco2_mtb_interrupt_cb_t *interrupt_cb)
	Configures a GPIO pin as an interrupt for the PAS CO2 sensor. More...
cy_rslt_t	xensiv_pasco2_mtb_read (const xensiv_pasco2_t *dev, uint16_t press_ref, uint16_t *co2_ppm_val)
	Reads the CO2 value value if available. More...

Function Documentation

xensiv_pasco2_mtb_init_i2c()

cy_rslt_t xensiv_pasco2_mtb_init_i2c	(	xensiv_pasco2_t *	dev,
		cyhal_i2c_t *	i2c
	)

Initializes the XENSIV™ PAS CO2 sensor and configures it to use the specified I2C peripheral.

Parameters

[in,out]	obj	Pointer to the ModusToolbox&trade PAS CO2 object. The caller must allocate the memory for this object but the init function will initialize its contents
[in]	i2c	Pointer to an initialized I2C object

Returns

CY_RSLT_SUCCESS if the initialization was successful; an error indicating what went wrong otherwise

xensiv_pasco2_mtb_init_uart()

cy_rslt_t xensiv_pasco2_mtb_init_uart	(	xensiv_pasco2_t *	dev,
		cyhal_uart_t *	uart
	)

Initializes the XENSIV™ PAS CO2 sensor, and configures it to use the specified UART peripheral.

Parameters

[in,out]	obj	Pointer to the ModusToolbox&trade PAS CO2 object. The caller must allocate the memory for this object but the init function will initialize its contents
[in]	uart	Pointer to an initialized UART object

Returns

CY_RSLT_SUCCESS if the initialization was successful; an error indicating what went wrong otherwise

xensiv_pasco2_mtb_interrupt_init()

cy_rslt_t xensiv_pasco2_mtb_interrupt_init	(	const xensiv_pasco2_t *	dev,
		const xensiv_pasco2_interrupt_config_t	int_config,
		uint16_t	alarm_threshold,
		cyhal_gpio_t	pin,
		uint8_t	intr_priority,
		cyhal_gpio_event_callback_t	callback,
		void *	callback_arg
	)

Configures a GPIO pin as an interrupt for the PAS CO2 sensor.

This initializes and configures the pin as an interrupt, and calls the PAS CO2 interrupt configuration API with the application-supplied settings structure

Note

Should be called only after xensiv_pasco2_mtb_init_i2c or xensiv_pasco2_mtb_init_uart.

Deprecated:

Use xensiv_pasco2_mtb_interrupt_init_ex

Parameters

[in]	dev	Pointer to the PAS CO2 sensor device
[in]	int_config	New sensor device interrupt configuration to apply
[in]	alarm_threshold	New alarm threshold value to apply
[in]	pin	Pin connected to the INT pin of the sensor
[in]	intr_priority	Priority for NVIC interrupt events
[in]	callback	Function to call when the specified event happens. Pass NULL to unregister the handler
[in]	callback_arg	Generic argument that will be provided to the callback when called; can be NULL

Returns

CY_RSLT_SUCCESS if interrupt was successfully enabled; an error occurred while initializing the pin otherwise

xensiv_pasco2_mtb_interrupt_init_ex()

cy_rslt_t xensiv_pasco2_mtb_interrupt_init_ex	(	xensiv_pasco2_t *	dev,
		const xensiv_pasco2_interrupt_config_t	int_config,
		uint16_t	alarm_threshold,
		cyhal_gpio_t	pin,
		uint8_t	intr_priority,
		xensiv_pasco2_mtb_interrupt_cb_t *	interrupt_cb
	)

Configures a GPIO pin as an interrupt for the PAS CO2 sensor.

This initializes and configures the pin as an interrupt, and calls the PAS CO2 interrupt configuration API with the application-supplied settings structure

Note

Should be called only after xensiv_pasco2_mtb_init_i2c or xensiv_pasco2_mtb_init_uart.

Parameters

[in]	obj	Pointer to the ModusToolbox&trade PAS CO2 sensor object
[in]	int_config	New sensor device interrupt configuration to apply
[in]	alarm_threshold	New alarm threshold value to apply
[in]	pin	Pin connected to the INT pin of the sensor
[in]	intr_priority	Priority for NVIC interrupt events
[in]	interrupt_cb	Interrupt callback

Note

Instances of this object are expected to persist for the length of time the callback is registered. As such, care must be given if declaring it on the stack to ensure the frame does not go away while the callback is still registered.

Returns

CY_RSLT_SUCCESS if interrupt was successfully enabled; an error occurred while initializing the pin otherwise

xensiv_pasco2_mtb_read()

cy_rslt_t xensiv_pasco2_mtb_read	(	const xensiv_pasco2_t *	dev,
		uint16_t	press_ref,
		uint16_t *	co2_ppm_val
	)

Reads the CO2 value value if available.

This checks whether a new CO2 value is available, in which case it returns it and sets the new pressure reference value for the next measurement

Parameters

[in]	obj	Pointer to the ModusToolbox&trade PAS CO2 object
[in]	press_ref	New pressure reference value to apply
[out]	co2_ppm_val	Pointer to populate with the CO2 ppm value

Returns

CY_RSLT_SUCCESS if PPM value was successfully read. XENSIV_PASCO2_RSLT_READ_NRDY if the measurement value is not ready yet; an error indicating what went wrong otherwise