Si7006/13/20/21/5x temperature and humidity sensors

Driver for the Si7006/13/20/21/5x temperature and humidity sensor. More...

Detailed Description

Driver for the Si7006/13/20/21/5x temperature and humidity sensor.

The Si70xx driver supports a range of similar temperature and humidity sensors from Silicon Labs.

The Si7006/13/20/21 sensors support both temperature and relative humidity reading, while the Si7050/1/3/4/5 sensors only provide a temperature reading varying in accuracy between +/- 0.1 C to +/- 1.0 C depending on the model.

For any of the Si705x models, use the pseudo module si705x.

This driver provides [S]ensor [A]ctuator [U]ber [L]ayer capabilities.

Files
file	si70xx.h
	Interface definition of the Si70xx driver.
file	si70xx_internals.h
	Internal definitions for Si7006/13/20/21.
file	si70xx_params.h
	Default configuration for Si7006/13/20/21.

Data Structures
struct	si70xx_params_t
	Device initialization parameters. More...
struct	si70xx_t
	Si70xx device descriptor. More...

Macros
#define	SI70XX_HAS_HUMIDITY_SENSOR   1
	Compile time macro telling whether the chip has a humidity sensor.

Enumerations
enum	{ SI70XX_OK , SI70XX_ERR_NODEV , SI70XX_ERR_I2C }
	Driver return codes. More...

Functions
int	si70xx_init (si70xx_t *dev, const si70xx_params_t *params)
	Initialize and reset the sensor. More...
uint16_t	si70xx_get_relative_humidity (const si70xx_t *dev)
	Read the relative humidity from the sensor. More...
int16_t	si70xx_get_temperature (const si70xx_t *dev)
	Read the current temperature from the sensor. More...
void	si70xx_get_both (const si70xx_t *dev, uint16_t *humidity, int16_t *temperature)
	Read the relative humidity and temperature from the sensor. More...
uint64_t	si70xx_get_serial (const si70xx_t *dev)
	Read the sensor serial number. More...
uint8_t	si70xx_get_id (const si70xx_t *dev)
	Read the sensor id, to identifier the sensor variant. More...
uint8_t	si70xx_get_revision (const si70xx_t *dev)
	Read the firmware revision of the sensor. More...

Enumeration Type Documentation

anonymous enum

anonymous enum

Driver return codes.

Enumerator
SI70XX_OK	All OK.
SI70XX_ERR_NODEV	No valid device found on I2C bus.
SI70XX_ERR_I2C	An error occurred when reading/writing on I2C bus.

Definition at line 55 of file si70xx.h.

Function Documentation

si70xx_get_both()

void si70xx_get_both	(	const si70xx_t *	dev,
		uint16_t *	humidity,
		int16_t *	temperature
	)

Read the relative humidity and temperature from the sensor.

Uses clock stretching.

This function is only available in models that have a humidity sensor.

Parameters

[in]	dev	device descriptor
[out]	humidity	pointer to relative humidity (in centi-percent)
[out]	temperature	pointer to temperature (in centi-degrees Celsius)

si70xx_get_id()

uint8_t si70xx_get_id

(

const si70xx_t *

dev

)

Read the sensor id, to identifier the sensor variant.

Parameters

[in]

dev

device descriptor

Returns

device id

si70xx_get_relative_humidity()

uint16_t si70xx_get_relative_humidity

(

const si70xx_t *

dev

)

Read the relative humidity from the sensor.

Uses clock stretching.

This function is only available in models that have a humidity sensor.

Parameters

[in]

dev

device descriptor

Returns

relative humidity in centi-percent (times 100)

si70xx_get_revision()

uint8_t si70xx_get_revision

(

const si70xx_t *

dev

)

Read the firmware revision of the sensor.

Parameters

[in]

dev

device descriptor

Returns

sensor firmware revision number

si70xx_get_serial()

uint64_t si70xx_get_serial

(

const si70xx_t *

dev

)

Read the sensor serial number.

Parameters

[in]

dev

device descriptor

Returns

sensor serial number

si70xx_get_temperature()

int16_t si70xx_get_temperature

(

const si70xx_t *

dev

)

Read the current temperature from the sensor.

Uses clock stretching.

Parameters

[in]

dev

device descriptor

Returns

current temperature in centi-degrees Celsius (times 100)

si70xx_init()

int si70xx_init	(	si70xx_t *	dev,
		const si70xx_params_t *	params
	)

Initialize and reset the sensor.

Parameters

[in]	dev	device descriptor
[in]	params	initialization parameters

Returns

SI70XX_OK on successful initialization

-SI70XX_ERR_NOI2C on I2C initialization error

-SI70XX_ERR_NODEV on device test error

-SI70XX_ERR_I2C on I2C bus error