Interface to the ST HTS221 capacitive digital sensor for relative humidity and temperature. More...

#include <nrfcxx/sensor/hts221.hpp>

Inheritance diagram for nrfcxx::sensor::hts221:

Data Structures
struct	calibration_type
	Structure for calibration information. More...

struct	iface_config_type
	Information required to communicate with a sensor instance. More...

struct	observations_type
	Structure used to return sampled values. More...

Public Types
enum	STATUS_REG_e : uint8_t { SR_T_DA = 0x01, SR_H_DA = 0x02, SR_READY = (SR_T_DA \| SR_H_DA) }
	Bit fields in the HTS221 `STATUS_REG` register. More...

enum	ODR_e : uint8_t { ODR_OneShot = 0x00, ODR_1_Hz = 0x01, ODR_7_Hz = 0x02, ODR_12p5_Hz = 0x03 }
	Bit field values in `CTRL_REG1` for observation data rate. More...

Public Member Functions
const iface_config_type &	iface_config () const
	Access the interface configuration for the sensor.

const calibration_type &	calibration () const
	Access the calibration constants. More...

int	status () const
	Return the value of the `STATUS` register.

const observations_type &	observations () const
	Access the most recent completed observation.

uint8_t	odr () const
	Retrieve the configured output data rate. More...

int	odr (uint8_t dr)
	Set the output data rate. More...

	hts221 (notifier_type notify, iface_config_type &ifc)
	Instantiate the device. More...

bool	drdy_asserted () const
	Programmatic test for whether `DRDY` is asserted.

int	lpsm_sample () override
	Post-extend to signal machine if start failed due to undetected drdy.

uint16_t	lost_drdy () const
	Count of the number of times a DRDY signal was detected to be lost.

Public Member Functions inherited from nrfcxx::lpm::lpsm_capable
virtual int	lpsm_start ()
	Validate and prepare to initiate an LPM collection. More...

lpm::state_machine::process_flags_type	lpsm_process ()
	Make progress on an LPM collection. More...

int	lpsm_stop ()

int	lpsm_reset ()

int	lpsm_process_rc () const
	Get the internal result code from the last invocation of lpsm_process_(). More...

const lpm::state_machine &	machine () const
	Gain read-only access to the LPM machine state.

Static Public Attributes
static constexpr uint16_t	INVALID_OBSERVATION = 30000
	Value used to indicate that observations are not valid.

static constexpr auto	ODR_DEFAULT = ODR_1_Hz
	The default output data rate.

Additional Inherited Members
Protected Types inherited from nrfcxx::lpm::lpsm_capable
using	state_type = state_machine::state_type

using	process_flags_type = state_machine::process_flags_type

Protected Member Functions inherited from nrfcxx::lpm::lpsm_capable
	lpsm_capable (notifier_type notify)
	Create a state machine that records state and supports delayed transitions. More...

virtual int	lpsm_process_ (int &delay, process_flags_type &pf)
	Override to implement machine-specific operations of lpsm_process(). More...

virtual void	lpsm_reset_ ()
	Override to reset state that is held outside the machine.

Protected Attributes inherited from nrfcxx::lpm::lpsm_capable
state_machine	machine_

Detailed Description

Interface to the ST HTS221 capacitive digital sensor for relative humidity and temperature.

Note

The application infrastructure support described in GPIOTE::irq_handler must be provided when using hts221, and the following put in the main routine after the hts221 instance has been constructed:

NVIC_EnableIRQ(GPIOTE_IRQn);
periph::GPIOTE::enable_sense();

lpm::lpsm_capable::lpsm_process() for this sensor returns the following flags in addition to the diagnostic flags:

lpm::state_machine::PF_OBSERVATION

Member Enumeration Documentation

◆ ODR_e

enum nrfcxx::sensor::hts221::ODR_e : uint8_t

Bit field values in CTRL_REG1 for observation data rate.

These may be configured using odr() when the LPM machine is off.

Enumerator
ODR_OneShot	On-demand observations. Invoke lpsm_start() to initiate an observation.
ODR_1_Hz	Observations generated at 1 Hz.
ODR_7_Hz	Observations generated at 7 Hz.
ODR_12p5_Hz	Observations generated at 12.5 Hz.

◆ STATUS_REG_e

enum nrfcxx::sensor::hts221::STATUS_REG_e : uint8_t

Bit fields in the HTS221 STATUS_REG register.

Enumerator
SR_T_DA	Bit set to indicate that new temperature data is available.
SR_H_DA	Bit set to indicate that new humidity data is available.
SR_READY	Value when all expected data is available.

Constructor & Destructor Documentation

◆ hts221()

nrfcxx::sensor::hts221::hts221	(	notifier_type	notify,
		iface_config_type &	ifc
	)

Instantiate the device.

Parameters

ifc	reference to an externally owned struct providing the resources required to communicate with the device.
notify	the mechanism by which the instance notifies the application that lpsm_process() should be invoked.

Member Function Documentation

◆ calibration()

const calibration_type& nrfcxx::sensor::hts221::calibration ( ) const

inline

Access the calibration constants.

This is useful for diagnostics.

◆ odr() [1/2]

uint8_t nrfcxx::sensor::hts221::odr ( ) const

inline

Retrieve the configured output data rate.

Returns: a value from ODR_e.

See also: ODR_DEFAULT

◆ odr() [2/2]

int nrfcxx::sensor::hts221::odr ( uint8_t dr )

Set the output data rate.

Note: This function will error if invoked while the LPM infrastructure is running.

Returns: non-negative on success, or a negative error code.

The documentation for this class was generated from the following file:

nrfcxx/sensor/hts221.hpp

Data Structures

Public Types

Public Member Functions

Static Public Attributes

Additional Inherited Members