Driver for the LM75 temperature sensor. More...

Detailed Description

Driver for the LM75 temperature sensor.

Author: Vitor Batista vitor.nosp@m..bat.nosp@m.ista@.nosp@m.ml-p.nosp@m.a.com

Definition in file lm75.h.

#include <stdbool.h>
#include "periph/i2c.h"
#include "periph/gpio.h"

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Data Structures
struct	lm75_properties
	temperature reading properties/resolutions struct of the LM75 sensors More...

struct	lm75_params
	params required for initialization More...

struct	lm75
	lm75 device descriptor More...

LM75 return values
enum	{ LM75_SUCCESS = 0 , LM75_ERROR_I2C , LM75_ERROR }

typedef struct lm75_properties	lm75_properties_t
	temperature reading properties/resolutions struct of the LM75 sensors

typedef struct lm75_params	lm75_params_t
	params required for initialization

typedef struct lm75	lm75_t
	lm75 device descriptor

lm75_properties_t	lm75a_properties
	declaration present in lm75.c

lm75_properties_t	tmp1075_properties
	declaration present in lm75.c

int	lm75_init (lm75_t dev, const lm75_params_t params)
	Initialization of the LM75 sensor.

int	lm75_get_temperature_raw (lm75_t dev, int temperature)
	Temperature values of LM75 sensor.

int	lm75_get_temperature (lm75_t dev, int temperature)
	Temperature values of LM75 sensor.

int	lm75_set_temp_limits (lm75_t dev, int temp_hyst, int temp_os, gpio_cb_t cb, void arg)
	Sets the values for Overtemperature shutdown(OS) and Hysteresis temperature(HYST).

int	lm75_get_os_temp (lm75_t dev, int temperature)
	Overshutdown temperature value of LM75 sensor.

int	lm75_get_hyst_temp (lm75_t dev, int temperature)
	Hysteresis temperature value of LM75 sensor.

int	lm75_get_os_pin (lm75_t dev, bool os_pin_state)
	Read the current state of the OS pin to see if it's active.

int	lm75_poweroff (lm75_t *dev)
	Activate the LM75 sensor shutdown mode.

int	lm75_poweron (lm75_t *dev)
	Deactivate the LM75 sensor shutdown mode.

int	tmp1075_one_shot (lm75_t *dev)
	Activates one shot conversion mode.

int	lm75_low_power_mode (lm75_t *dev, uint16_t interval)
	Activates low power mode operation.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Definition at line 40 of file lm75.h.

Function Documentation

◆ lm75_get_hyst_temp()

int lm75_get_hyst_temp	(	lm75_t *	dev,
		int *	temperature
	)

Hysteresis temperature value of LM75 sensor.

Reads the sensor hysteresis temperature value from THYST_REG in ºC.

Parameters

[in]	dev	device structure
[out]	temperature	buffer where HYST temperature value will be written

Returns: LM75_SUCCESS, on success; LM75_ERROR_I2C, on I2C related error

◆ lm75_get_os_pin()

int lm75_get_os_pin	(	lm75_t *	dev,
		bool *	os_pin_state
	)

Read the current state of the OS pin to see if it's active.

Read the configuration register to see the OS pin's polarity and then reads its state. Then outputs if the pin is active and whether it's in the low and active or high and active.

Parameters

[in]	dev	device structure
[out]	os_pin_state	pointer to the state of the OS pin - 0 for inactive and 1 for active

Returns: LM75_SUCCESS, on success; LM75_ERROR, on pin reading error

◆ lm75_get_os_temp()

int lm75_get_os_temp	(	lm75_t *	dev,
		int *	temperature
	)

Overshutdown temperature value of LM75 sensor.

Reads the sensor OS temperature value from TOS_REG in ºC.

Parameters

[in]	dev	device structure
[out]	temperature	buffer where OS temperature value will be written

Returns: LM75_SUCCESS, on success; LM75_ERROR_I2C, on I2C related error

◆ lm75_get_temperature()

int lm75_get_temperature	(	lm75_t *	dev,
		int *	temperature
	)

Temperature values of LM75 sensor.

Gets the device's temperature register with the lm75_get_temperature_raw function and then returns the values in mºC, truncating values smaller than this, if available

Parameters

[in]	dev	device structure
[in]	temperature	buffer where temperature value will be written in mºC

Returns: LM75_SUCCESS, on success; LM75_ERROR, on error

◆ lm75_get_temperature_raw()

int lm75_get_temperature_raw	(	lm75_t *	dev,
		int *	temperature
	)

Temperature values of LM75 sensor.

Reads the sensor temperature values from TEMP_REG the value is given with the full precision the device is capable of If divided by the device's mult property, the result will be the temperature in ºC and the remainder of that division will be the decimal part of the temperature, at the maximum resolution the device is capable of.

Parameters

[in]	dev	device structure
[in]	temperature	buffer where temperature value will be written

Returns: LM75_SUCCESS, on success; LM75_ERROR_I2C, on I2C related error

◆ lm75_init()

int lm75_init	(	lm75_t *	dev,
		const lm75_params_t *	params
	)

Initialization of the LM75 sensor.

Initializes the sensor according to specific input parameters.

Parameters

[out]	dev	device structure to initialize
[in]	params	initialization parameters

Returns: LM75_SUCCESS, on success; LM75_ERROR_I2C, on I2C related error; LM75_ERROR, on initialization related error

◆ lm75_low_power_mode()

int lm75_low_power_mode	(	lm75_t *	dev,
		uint16_t	interval
	)

Activates low power mode operation.

This function makes the device measure temperatures in a strictly discrete way at a user definable rate, as opposed to performing continuous measurements at the device's conversion rate. It allows the device to stay in shutdown mode for the most part, therefore consuming less power. In the tmp1075 and other devices which have the one shot feature this is done automatically. In the LM75A sensor nd other sensors which lack the one shot mode feature this is done manually by switching the device to and from shutdown mode and staying awake at least long enough to perform one ne measurement.

Parameters

[in]	dev	device structure
[in]	interval	time interval in ms between measurements

Returns: LM75_ERROR if unsuccessful; LM75_SUCCESS if successful

◆ lm75_poweroff()

int lm75_poweroff ( lm75_t * dev )

Activate the LM75 sensor shutdown mode.

Parameters

[in] dev device structure to set into shutdown mode

Returns: LM75_SUCCESS, on success; LM75_ERROR, on mode switching related error

◆ lm75_poweron()

int lm75_poweron ( lm75_t * dev )

Deactivate the LM75 sensor shutdown mode.

Parameters

[in] dev device structure to wake up from shutdown mode

Returns: LM75_SUCCESS, on success; LM75_ERROR, on mode switching related error

◆ lm75_set_temp_limits()

int lm75_set_temp_limits	(	lm75_t *	dev,
		int	temp_hyst,
		int	temp_os,
		gpio_cb_t	cb,
		void *	arg
	)

Sets the values for Overtemperature shutdown(OS) and Hysteresis temperature(HYST).

OS gives the temperature's higher bound and HYST the lower bound values are rounded to the lowest value that the device supports,

Parameters

[in]	dev	device structure
[in]	temp_os	desired OS temperature in mºC
[in]	temp_hyst	desired HYST temperature in mºC
[in]	cb	callback that is called from interrupt context
[in]	*arg	optional arguments for the gpio_init_int function

Returns: LM75_SUCCESS, on success; LM75_ERROR_I2C, on I2C related error; LM75_ERROR, on temperature setting related error

◆ tmp1075_one_shot()

int tmp1075_one_shot ( lm75_t * dev )

Activates one shot conversion mode.

Wakes from shutdown mode, does a single temperature conversion and writes in into the temperature register and then goes back into shutdown

Parameters

[in] dev device structure

Returns: LM75_ERROR if unsuccessful; LM75_SUCCESS if successful

Detailed Description

Data Structures

LM75 return values

Enumeration Type Documentation

◆ anonymous enum

Function Documentation

◆ lm75_get_hyst_temp()

◆ lm75_get_os_pin()

◆ lm75_get_os_temp()

◆ lm75_get_temperature()

◆ lm75_get_temperature_raw()

◆ lm75_init()

◆ lm75_low_power_mode()

◆ lm75_poweroff()

◆ lm75_poweron()

◆ lm75_set_temp_limits()

◆ tmp1075_one_shot()