m5::unit::UnitSHT40 Class Reference

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 ()
	Gets the configration.
void	config (const config_t &cfg)
	Set the configration.
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	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.
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 {}
config_t	_cfg {}
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

measureSingleshot()

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]	data	Measuerd 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

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()

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 "keepingin mind that the heater is designed for a maximal duty cycle of less than 5%"

stopPeriodicMeasurement()

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

inline

Stop periodic measurement.

Returns

True if successful