AT30TSE75x temperature sensor with EEPROM

Detailed Description

The connection between the MCU and the AT30TSE75x is based on the I2C-interface. There are 3 versions of this IC, with either 2/4/8 Kb of EEPROM.

Files
file	at30tse75x.h
	Driver for the AT30TSE75x temperature sensor with serial EEPROM.

Data Structures
struct	at30tse75x_t
	Device descriptor for a AT30TSE75x device. More...

Functions
int	at30tse75x_init (at30tse75x_t *dev, i2c_t i2c, uint8_t addr)
	Initialize a AT30TSE75x device. More...
int	at30tse75x_save_config (const at30tse75x_t *dev)
	Save configuration register to non-volatile backup register. More...
int	at30tse75x_restore_config (const at30tse75x_t *dev)
	Restore configuration register from non-volatile backup register. More...
int	at30tse75x_get_config (const at30tse75x_t *dev, uint8_t *data)
	Get content of configuration register. More...
int	at30tse75x_set_config (const at30tse75x_t *dev, uint8_t data)
	Set content of configuration register. More...
int	at30tse75x_set_resolution (const at30tse75x_t *dev, at30tse75x_resolution_t resolution)
	Set temperature resolution. More...
int	at30tse75x_set_mode (const at30tse75x_t *dev, at30tse75x_mode_t mode)
	Set operation mode. More...
int	at30tse75x_set_alarm_polarity (const at30tse75x_t *dev, at30tse75x_alarm_polatity_t polarity)
	Set polarity of ALERT pin. More...
int	at30tse75x_set_fault_tolerance (const at30tse75x_t *dev, at30tse75x_fault_tolerance_t tolerance)
	Set tolerance to outlying measurements. More...
int	at30tse75x_set_limit_low (const at30tse75x_t *dev, int8_t t_low)
	Set T_Low limit. More...
int	at30tse75x_set_limit_high (const at30tse75x_t *dev, int8_t t_high)
	Set T_High limit. More...
int	at30tse75x_get_temperature (const at30tse75x_t *dev, float *temperature)
	Get measured temperature. More...

AT30TSE75x I2C addresses
#define	AT30TSE75X_TEMP_ADDR   (0x48)
#define	AT30TSE75X_EEPROM_ADDR   (0x50)

AT30TSE75x register addresses
#define	AT30TSE75X_REG__TEMPERATURE   (0x00)
#define	AT30TSE75X_REG__CONFIG   (0x01)
#define	AT30TSE75X_REG__LIMIT_LOW   (0x02)
#define	AT30TSE75X_REG__LIMIT_HIGH   (0x03)
#define	AT30TSE75X_REG__NV_CONFIG   (0x11)
#define	AT30TSE75X_REG__NV_LIMIT_LOW   (0x12)
#define	AT30TSE75X_REG__NV_LIMIR_HIGH   (0x13)

AT30TSE75x number formatting
#define	AT30TSE75X_INTEGER_MASK   (0x00ff)
#define	AT30TSE75X_INTEGER_SHIFT   (0)
#define	AT30TSE75X_FRACTIONAL_MASK   (0xf000)
#define	AT30TSE75X_FRACTIONAL_SHIFT   (12)
#define	AT30TSE75X_FRACTIONAL_BASE   (0.0625f)

AT30TSE75x configuration register
Only upper byte can be read/written, so treat as 8-bit register.
#define	AT30TSE75X_CONFIG__OS_BIT   (1 << 7)
#define	AT30TSE75X_CONFIG__RESOLUTION_MASK   (0x60)
#define	AT30TSE75X_CONFIG__RESOLUTION_SHIFT   (5)
#define	AT30TSE75X_CONFIG__FTQ_MASK   (0x18)
#define	AT30TSE75X_CONFIG__FTQ_SHIFT   (3)
#define	AT30TSE75X_CONFIG__ALERT_POL_BIT   (1 << 2)
#define	AT30TSE75X_CONFIG__ALARM_MODE_BIT   (1 << 1)
#define	AT30TSE75X_CONFIG__SHUTDOWN_BIT   (1 << 0)

AT30TSE75x commands
#define	AT30TSE75X_CMD__SAVE_TO_NVRAM   (0x48)
#define	AT30TSE75X_CMD__RESTORE_FROM_NVRAM   (0xb8)
#define	AT30TSE75X_CMD__GENERAL_CALL_RESET   (0x06)
#define	AT30TSE75X_CMD__GENERAL_CALL_RELATCH   (0x04)

AT30TSE75x constants
#define	AT30TSE75X_BUS_FREE_TIME_US   (1U)

AT30TSE75x configuration types
enum	at30tse75x_resolution_t { AT30TSE75X_RESOLUTION_9BIT = 0, AT30TSE75X_RESOLUTION_10BIT = 1, AT30TSE75X_RESOLUTION_11BIT = 2, AT30TSE75X_RESOLUTION_12BIT = 3 }
	Temperature resolution.
enum	at30tse75x_mode_t { AT30TSE75X_MODE_COMPARATOR, AT30TSE75X_MODE_INTERRUPT, AT30TSE75X_MODE_ONE_SHOT }
	Operation mode. More...
enum	at30tse75x_fault_tolerance_t { AT30TSE75X_ALARM_AFTER_1 = 0, AT30TSE75X_ALARM_AFTER_2 = 1, AT30TSE75X_ALARM_AFTER_4 = 2, AT30TSE75X_ALARM_AFTER_6 = 3 }
	After how many limit exceeding measurements the ALERT pin is set.
enum	at30tse75x_alarm_polatity_t { AT30TSE75X_ALARM_ACTIVE_LOW, AT30TSE75X_ALARM_ACTIVE_HIGH }
	Polarity of the ALERT pin.

Enumeration Type Documentation

at30tse75x_mode_t

enum at30tse75x_mode_t

Operation mode.

The device can run in continuous or one-shot mode. While in one-shot mode it is effectively shutdown and only wakes up to perform a single measurement. When in comparator or interrupt mode, the device samples contiously the temperature and sets the ALERT pin according to the chosen mode.

Definition at line 126 of file at30tse75x.h.

Function Documentation

at30tse75x_get_config()

int at30tse75x_get_config	(	const at30tse75x_t *	dev,
		uint8_t *	data
	)

Get content of configuration register.

Parameters

[in]	dev	device descriptor
[out]	data	buffer where config register will be written to

Returns

0 on success

-1 on error

at30tse75x_get_temperature()

int at30tse75x_get_temperature	(	const at30tse75x_t *	dev,
		float *	temperature
	)

Get measured temperature.

Parameters

[in]	dev	device descriptor
[out]	temperature	float buffer where temperature will be written to

Returns

0 on success

-1 on error

at30tse75x_init()

int at30tse75x_init	(	at30tse75x_t *	dev,
		i2c_t	i2c,
		uint8_t	addr
	)

Initialize a AT30TSE75x device.

Parameters

[out]	dev	device descriptor
[in]	i2c	I2C bus the device is connected to
[in]	addr	I2C address of the device

The valid address range is 0x48 - 0x4f depending on the configuration of the address pins A0-A2.

Returns

0 on success

-1 on error

-2 on invalid address

at30tse75x_restore_config()

int at30tse75x_restore_config

(

const at30tse75x_t *

dev

)

Restore configuration register from non-volatile backup register.

Parameters

[in]

dev

device descriptor

Returns

0 on success

-1 on error

at30tse75x_save_config()

int at30tse75x_save_config

(

const at30tse75x_t *

dev

)

Save configuration register to non-volatile backup register.

Parameters

[in]

dev

device descriptor

Returns

0 on success

-1 on error

at30tse75x_set_alarm_polarity()

int at30tse75x_set_alarm_polarity	(	const at30tse75x_t *	dev,
		at30tse75x_alarm_polatity_t	polarity
	)

Set polarity of ALERT pin.

Parameters

[in]	dev	device descriptor
[in]	polarity	polarity of ALERT pin

Returns

0 on success

-1 on device error

-2 on bad user input

at30tse75x_set_config()

int at30tse75x_set_config	(	const at30tse75x_t *	dev,
		uint8_t	data
	)

Set content of configuration register.

Parameters

[in]	dev	device descriptor
[in]	data	new value for configuration register

Returns

0 on success

-1 on error

at30tse75x_set_fault_tolerance()

int at30tse75x_set_fault_tolerance	(	const at30tse75x_t *	dev,
		at30tse75x_fault_tolerance_t	tolerance
	)

Set tolerance to outlying measurements.

Parameters

[in]	dev	device descriptor
[in]	tolerance	tolerance

Returns

0 on success

-1 on device error

-2 on bad user input

at30tse75x_set_limit_high()

int at30tse75x_set_limit_high	(	const at30tse75x_t *	dev,
		int8_t	t_high
	)

Set T_High limit.

Parameters

[in]	dev	device descriptor
[in]	t_high	upper temperature limit

Returns

0 on success

-1 on error

at30tse75x_set_limit_low()

int at30tse75x_set_limit_low	(	const at30tse75x_t *	dev,
		int8_t	t_low
	)

Set T_Low limit.

Parameters

[in]	dev	device descriptor
[in]	t_low	lower temperature limit

Returns

0 on success

-1 on device error

-2 on bad user input

at30tse75x_set_mode()

int at30tse75x_set_mode	(	const at30tse75x_t *	dev,
		at30tse75x_mode_t	mode
	)

Set operation mode.

Parameters

[in]	dev	device descriptor
[in]	mode	operation mode

Returns

0 on success

-1 on device error

-2 on bad user input

at30tse75x_set_resolution()

int at30tse75x_set_resolution	(	const at30tse75x_t *	dev,
		at30tse75x_resolution_t	resolution
	)

Set temperature resolution.

Parameters

[in]	dev	device descriptor
[in]	resolution	temperature resolution

Returns

0 on success

-1 on error

-2 on bad user input