HSxxxx Sensor API

API providing a unified interface for Renesas Humidity and Temperature sensors. More...

Modules
	HS3xxx Sensor API
	HS3xxx Temperature/Humidity Sensor API.
	HS4xxx Sensor API
	HS4xxx Temperature/Humidity Sensor API.

Files
file	hsxxxx.h
	Renesas humidity sensors (HS3xxx, HS4xxx) abstraction.

Functions
int	HSxxxx_Init (HSxxxx_t *sensor, Interface_t *hal)
	Initialize the sensor object. More...
int	HSxxxx_Measure (HSxxxx_t *sensor, HSxxxx_Results_t *results)
	Perform one temperature measurement. More...
char const *	HSxxxx_Name (HSxxxx_t *sensor)
	Return the temperature/humidity sensor type name. More...

Data Structures
struct	HSxxxx_Results_t
	Data structure holding humidity/temperature results. More...
struct	HSxxxx_t
	Data structure holding information required for HSxxxx API operation. More...

Detailed Description

API providing a unified interface for Renesas Humidity and Temperature sensors.

The Renesas HS3xxx and HS4xxx are highly accurate, ultra-low power, fully calibrated relative humidity and temperature sensors. These sensors may be used as standalone sensors or used as companion sensor for humidity and temperature sensitive applications (e.g., for Renesas gas sensors).

The present API is provided as a unified interface to both of these sensor types.

HAL API Requirements

HAL API ports to a customer specific hardware require the following function pointers of the Interface_t HAL data structure to be initialized and working as documented:

Function Pointer	Required
i2cRead	Mandatory
i2cWrite	Mandatory
msSleep	Mandatory
reset	Not required

---

Data Structure Documentation

HSxxxx_Results_t

struct HSxxxx_Results_t

Data structure holding humidity/temperature results.

Data Fields
float	temperature
float	humidity

Field Documentation

humidity

float humidity

Relative humidity

temperature

float temperature

Temperature value in degree Celsius

HSxxxx_t

struct HSxxxx_t

Data structure holding information required for HSxxxx API operation.

Data Fields
Interface_t *	interface
uint8_t	i2cAddress

Field Documentation

i2cAddress

uint8_t i2cAddress

I2C slave address of the HSxxxx sensor

interface

Interface_t* interface

Pointer to the hal object for physical communication

Function Documentation

HSxxxx_Init()

int HSxxxx_Init	(	HSxxxx_t *	sensor,
		Interface_t *	hal
	)

Initialize the sensor object.

This function tries searching for a HS4xxx sensor first, by accessing the corresponding I2C address. If no such sensor is found, the function searches for a HS3xxx.

The type of sensor being detected can be determined using the function HSxxxx_Name().

Parameters

sensor	Pointer to sensor object to be initialized.
hal	Pointer to hal object for physical communication.

Returns

int Error code

Return values

0	On success
other	On error

HSxxxx_Measure()

int HSxxxx_Measure	(	HSxxxx_t *	sensor,
		HSxxxx_Results_t *	results
	)

Perform one temperature measurement.

This function starts a temperature/humidity measurement and waits for the availability of the result before it returns.

Note

This function is implemented as blocking function. Thus while the measurement is ongoing no other code is executed. Depending on the sensor the bocking time may be multiple tens of milliseconds.

Parameters

sensor	Pointer to the sensor object to be used.
results	Pointer to data structure for result storage.

Returns

int Error code

Return values

0	On success
other	On error

HSxxxx_Name()

char const* HSxxxx_Name

(

HSxxxx_t *

sensor

)

Return the temperature/humidity sensor type name.

The function HSxxxx_Init can identify different types of temperature/ humidity sensors. This function may be used to determine the sensor type that has been identified. The identification is performed based on the sensors I2C address.

Parameters

sensor

Pointer to the sensor object to be queried.

Returns

int Error code

Return values

0	On success
other	On error