ADT7310 SPI temperature sensor

Driver for the Analog Devices ADT7310 temperature sensor. More...

Detailed Description

Driver for the Analog Devices ADT7310 temperature sensor.

Description

The ADT7310 is a high accuracy digital temperature sensor in a narrow SOIC package. It contains a band gap temperature reference and a 13-bit ADC to monitor and digitize the temperature to a 0.0625°C resolution. The ADC resolution, by default, is set to 13 bits (0.0625 °C). This can be changed to 16 bits (0.0078 °C) by setting Bit 7 in the configuration register (Register Address 0x01). The ADT7310 is guaranteed to operate over supply voltages from 2.7 V to 5.5 V. Operating at 3.3 V, the average supply current is typically 210 μA. The ADT7310 has a shutdown mode that powers down the device and offers a shutdown current of typically 2 μA. The ADT7310 is rated for operation over the −55°C to +150°C temperature range.

Usage

See tests/driver_adt7310 for an example application using this driver.

Caveats

This driver is currently missing support for a number of hardware features:

• Interrupt and compare pins are not handled
• There is no public API for setting the temperature alarm levels
• Device SPI reset is not implemented (drive MISO high from the master while clocking SCK)

Files
file	adt7310.h
	Interface definition for the ADT7310 sensor driver.

Data Structures
struct	adt7310_t
	Device descriptor for ADT7310 sensors. More...

Functions
int	adt7310_set_config (adt7310_t *dev, uint8_t config)
	Set configuration register of an ADT7310 sensor. More...
int	adt7310_init (adt7310_t *dev, spi_t spi, spi_clk_t clk, gpio_t cs)
	Initialize the ADT7310 sensor driver. More...
int16_t	adt7310_read_raw (const adt7310_t *dev)
	Read raw temperature register value. More...
int32_t	adt7310_read (const adt7310_t *dev)
	Read temperature value from sensor and convert to milli-degrees Celsius. More...
float	adt7310_read_float (const adt7310_t *dev)
	Read temperature value from sensor and convert to degrees Celsius. More...

ADT7310 configuration bits
#define	ADT7310_CONF_FAULT_QUEUE_MASK   (0x03)
#define	ADT7310_CONF_FAULT_QUEUE_SHIFT   (0)
#define	ADT7310_CONF_FAULT_QUEUE(x)   (((x) << ADT7310_CONF_FAULT_QUEUE_SHIFT) & ADT7310_CONF_FAULT_QUEUE_MASK)
#define	ADT7310_CONF_CT_POL_MASK   (0x04)
#define	ADT7310_CONF_CT_POL_SHIFT   (2)
#define	ADT7310_CONF_CT_POL(x)   (((x) << ADT7310_CONF_CT_POL_SHIFT) & ADT7310_CONF_CT_POL_MASK)
#define	ADT7310_CONF_INT_POL_MASK   (0x08)
#define	ADT7310_CONF_INT_POL_SHIFT   (3)
#define	ADT7310_CONF_INT_POL(x)   (((x) << ADT7310_CONF_INT_POL_SHIFT) & ADT7310_CONF_INT_POL_MASK)
#define	ADT7310_CONF_INTCT_MODE_MASK   (0x10)
#define	ADT7310_CONF_INTCT_MODE_SHIFT   (4)
#define	ADT7310_CONF_INTCT_MODE(x)   (((x) << ADT7310_CONF_INTCT_MODE_SHIFT) & ADT7310_CONF_INTCT_MODE_MASK)
#define	ADT7310_CONF_OPERATION_MODE_MASK   (0x60)
#define	ADT7310_CONF_OPERATION_MODE_SHIFT   (5)
#define	ADT7310_CONF_OPERATION_MODE(x)   (((x) << ADT7310_CONF_OPERATION_MODE_SHIFT) & ADT7310_CONF_OPERATION_MODE_MASK)
#define	ADT7310_CONF_RESOLUTION_MASK   (0x80)
#define	ADT7310_CONF_RESOLUTION_SHIFT   (7)
#define	ADT7310_CONF_RESOLUTION(x)   (((x) << ADT7310_CONF_RESOLUTION_SHIFT) & ADT7310_CONF_RESOLUTION_MASK)
#define	ADT7310_MODE_CONTINUOUS   (ADT7310_CONF_OPERATION_MODE(0))
	Continuous operation mode.
#define	ADT7310_MODE_ONE_SHOT   (ADT7310_CONF_OPERATION_MODE(1))
	One shot.
#define	ADT7310_MODE_1SPS   (ADT7310_CONF_OPERATION_MODE(2))
	1 sample per second
#define	ADT7310_MODE_SHUTDOWN   (ADT7310_CONF_OPERATION_MODE(3))
	Shut down (powersave)

Function Documentation

adt7310_init()

int adt7310_init	(	adt7310_t *	dev,
		spi_t	spi,
		spi_clk_t	clk,
		gpio_t	cs
	)

Initialize the ADT7310 sensor driver.

Note

The SPI bus is expected to have been initialized when adt7310_init is called.

Parameters

[in]	dev	pointer to sensor device descriptor
[in]	spi	SPI bus the sensor is connected to
[in]	clk	SPI bus speed
[in]	cs	GPIO pin the chip select signal is connected to

Returns

0 on success

<0 on error

adt7310_read()

int32_t adt7310_read

(

const adt7310_t *

dev

)

Read temperature value from sensor and convert to milli-degrees Celsius.

Divide the returned value by 1000 to get integer degrees.

Parameters

[in]

dev

pointer to sensor device descriptor

Returns

temperature in milli-degrees Celsius

INT32_MIN on errors

adt7310_read_float()

float adt7310_read_float

(

const adt7310_t *

dev

)

Read temperature value from sensor and convert to degrees Celsius.

Parameters

[in]

dev

pointer to sensor device descriptor

Returns

floating point representation of temperature in degrees Celsius

NaN on errors

adt7310_read_raw()

int16_t adt7310_read_raw

(

const adt7310_t *

dev

)

Read raw temperature register value.

Note

The three least-significant bits of the value register are used for flags if the sensor is configured for 13 bit mode.

Parameters

[in]

dev

pointer to sensor device descriptor

Returns

raw sensor value on success

INT16_MIN on error

adt7310_set_config()

int adt7310_set_config	(	adt7310_t *	dev,
		uint8_t	config
	)

Set configuration register of an ADT7310 sensor.

Parameters

[in]	dev	pointer to sensor device descriptor
[in]	config	configuration byte, see macros in adt7310.h

Returns

0 on success

-1 on error