Temperature and humidity, sensor unit. More...

#include <unit_SHT40.hpp>

Inheritance diagram for m5::unit::UnitSHT40:

Classes
struct	config_t
	Settings for begin. More...

Public Member Functions
	UnitSHT40 (const uint8_t addr=DEFAULT_ADDRESS)

virtual bool	begin () override

virtual void	update (const bool force=false) override

Settings for begin
config_t	config () const
	Gets the configuration.

void	config (const config_t &cfg)
	Set the configuration.

Measurement data by periodic
float	temperature () const
	Oldest measured temperature (Celsius)

float	celsius () const
	Oldest measured temperature (Celsius)

float	fahrenheit () const
	Oldest measured temperature (Fahrenheit)

float	humidity () const
	Oldest measured humidity (RH)

Periodic measurement
bool	startPeriodicMeasurement (const sht40::Precision precision, const sht40::Heater heater, const float duty=0.05f)
	Start periodic measurement.

bool	startPeriodicMeasurement (const sht40::HeaterPower power, const sht40::HeaterDuration duration, const float duty=0.05f)
	Start periodic measurement with heater.

bool	startPeriodicMeasurement ()
	Start periodic measurement using previous settings.

bool	stopPeriodicMeasurement ()
	Stop periodic measurement.

Single shot measurement
bool	measureSingleshot (sht40::Data &d, const sht40::Precision precision=sht40::Precision::High, const sht40::Heater heater=sht40::Heater::None)
	Measurement single shot.

bool	measureSingleshot (sht40::Data &d, const sht40::HeaterPower power, const sht40::HeaterDuration duration)
	Measurement single shot with heater.

Reset
bool	softReset ()
	Soft reset.

bool	generalReset ()
	General reset.

Serial number
bool	readSerialNumber (uint32_t &serialNumber)
	Read the serial number value.

bool	readSerialNumber (char *serialNumber)
	Read the serial number string.

Protected Member Functions
bool	start_periodic_measurement (const sht40::Precision precision, const sht40::Heater heater, const float duty)

bool	stop_periodic_measurement ()

bool	read_measurement (sht40::Data &d)

void	reset_status ()

bool	soft_reset ()

	M5_UNIT_COMPONENT_PERIODIC_MEASUREMENT_ADAPTER_HPP_BUILDER (UnitSHT40, sht40::Data)

Protected Attributes
std::unique_ptr< m5::container::CircularBuffer< sht40::Data > >	_data {}

uint8_t	_cmd {}

uint8_t	_measureCmd {}

types::elapsed_time_t	_latest_heater {}

types::elapsed_time_t	_interval_heater {}

uint32_t	_duration_measure {}

uint32_t	_duration_heater {}

Detailed Description

Temperature and humidity, sensor unit.

Member Function Documentation

◆ generalReset()

bool m5::unit::UnitSHT40::generalReset ( )

General reset.

Reset using I2C general call

Returns: True if successful

Warning: This is a reset by General command, the command is also sent to all devices with I2C connections; Not supported with m5::I2C_Class. The bus hangs because m5::I2C_Class has no timeout on bus recovery after a general call reset

◆ measureSingleshot() [1/2]

bool m5::unit::UnitSHT40::measureSingleshot	(	sht40::Data &	d,
		const sht40::HeaterPower	power,
		const sht40::HeaterDuration	duration )

Measurement single shot with heater.

Parameters

[out]	d	Measured data
	power	Heater power level
	duration	Heater activation duration

Returns: True if successful

Note: Always performs high precision measurement regardless of heater power level; Blocking until the process is complete

Warning: During periodic detection runs, an error is returned; During heater operation, sensor specifications are not valid

◆ measureSingleshot() [2/2]

bool m5::unit::UnitSHT40::measureSingleshot	(	sht40::Data &	d,
		const sht40::Precision	precision = sht40::Precision::High,
		const sht40::Heater	heater = sht40::Heater::None )

Measurement single shot.

Parameters

[out]	d	Measured data
	precision	Sensor precision
	heater	Heater behavior

Returns: True if successful

Note: Blocking until the process is complete

Warning: During periodic detection runs, an error is returned; If heater is activated, the accuracy of the returned value is not guaranteed

Deprecated: Use measureSingleshot(Data&, Precision) for no-heater or measureSingleshot(Data&, HeaterPower, HeaterDuration) for heater measurement. When heater != None, the Precision parameter selects heater power, not measurement precision.

See also: UnitSHT40::startPeriodicMeasurement

◆ readSerialNumber() [1/2]

bool m5::unit::UnitSHT40::readSerialNumber ( char * serialNumber )

Read the serial number string.

Parameters

[out] serialNumber Output buffer

Returns: True if successful

Warning: serialNumber must be at least 9 bytes; During periodic detection runs, an error is returned

◆ readSerialNumber() [2/2]

bool m5::unit::UnitSHT40::readSerialNumber ( uint32_t & serialNumber )

Read the serial number value.

Parameters

[out] serialNumber serial number value

Returns: True if successful

Note: The serial number is 32 bit

Warning: During periodic detection runs, an error is returned

◆ softReset()

bool m5::unit::UnitSHT40::softReset ( )

Soft reset.

Returns: True if successful

◆ startPeriodicMeasurement() [1/3]

bool m5::unit::UnitSHT40::startPeriodicMeasurement ( )

inline

Start periodic measurement using previous settings.

Returns: True if successful

Note: Uses the precision, heater, and duty settings from the last successful startPeriodicMeasurement or begin

◆ startPeriodicMeasurement() [2/3]

bool m5::unit::UnitSHT40::startPeriodicMeasurement	(	const sht40::HeaterPower	power,
		const sht40::HeaterDuration	duration,
		const float	duty = 0.05f )

inline

Start periodic measurement with heater.

Parameters

power	Heater power level
duration	Heater activation duration
duty	Duty for activate heater [~ 0.05f]

Returns: True if successful

Note: Always performs high precision measurement regardless of heater power level

Warning: Datasheet says "keeping in mind that the heater is designed for a maximal duty cycle of less than 5%"

◆ startPeriodicMeasurement() [3/3]

bool m5::unit::UnitSHT40::startPeriodicMeasurement	(	const sht40::Precision	precision,
		const sht40::Heater	heater,
		const float	duty = 0.05f )

inline

Start periodic measurement.

Parameters

precision	Sensor precision
heater	Heater behavior
duty	Duty for activate heater

Returns: True if successful

Note: If the heater is Long or Short, the heater will be active periodically within the specified duty

Warning: Datasheet says "keeping in mind that the heater is designed for a maximal duty cycle of less than 5%"

Deprecated: Use startPeriodicMeasurement(Precision) for no-heater or startPeriodicMeasurement(HeaterPower, HeaterDuration, float) for heater measurement. When heater != None, the Precision parameter selects heater power, not measurement precision.

◆ stopPeriodicMeasurement()

bool m5::unit::UnitSHT40::stopPeriodicMeasurement ( )

inline

Stop periodic measurement.

Returns: True if successful

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

◆ generalReset()

◆ measureSingleshot() [1/2]

◆ measureSingleshot() [2/2]

◆ readSerialNumber() [1/2]

◆ readSerialNumber() [2/2]

◆ softReset()

◆ startPeriodicMeasurement() [1/3]

◆ startPeriodicMeasurement() [2/3]

◆ startPeriodicMeasurement() [3/3]

◆ stopPeriodicMeasurement()