Functions
ssize_t	ds18b20_check_family_code (uint8_t *rom)
	Verifies that the family code stored in rom first byte belongs to the driver supported device. Data read is CRC8 checked before a success is reported. More...

ssize_t	ds18b20_config (uint8_t *rom, int8_t th, int8_t tl, uint8_t resolution)
	Configures resolution and alarm registers of a specific DS18B20. More...

ssize_t	ds18b20_eeprom_recall (uint8_t *rom)
	Restores data from permanent EEPROM (TH, TL and configuration registers) to scratchpad memory. More...

ssize_t	ds18b20_parasite_powered (uint8_t *rom)
	Checks wether the DS18B20 is parasite powered. More...

ssize_t	ds18b20_read_temp (uint8_t rom, int16_t temperature)
	Reads temperature registers from DS18B20. If device is parasite-powered a strong pull-up is necessary. More...

ssize_t	ds18b20_scratchpad_copy (uint8_t *rom)
	Copies data from scratchpad memory (TH, TL and configuration registers) to permanent EEPROM. If device is parasite-powered a strong pull-up is necessary. More...

ssize_t	ds18b20_scratchpad_read (uint8_t rom, uint8_t scratchpad)
	Reads the content of scratchpad memory (temperature, triggers and configuration registers) from DS18B20. Data read is CRC8 checked before a success is reported. More...

int16_t	ds18b20_temp_conv (uint8_t *temp_regs)
	Performs a conversion of the temperature read from DS18B20. More...

ssize_t	ds1904_check_family_code (uint8_t *rom)
	Verifies that the family code stored in rom first byte belongs to the driver supported device. Data read is CRC8 checked before a success is reported. More...

Detailed Description

DS18B20 API Overview

This API contains the functions to configure and control a DS18B20 temperature sensor over a 1-Wire bus.

DS18B20 functions:

DS18B20 Macros

The DS18B20 temperature sensor has 6 specific commands that are defined as the following macros:

DS18B20_TEMP_CONV: Performs a temperature conversion and copies it to scratchpad memory.
DS18B20_SCRPD_CPY: Copies scratchpad memory values to device's EEPROM (only config, TH and TL registers).
DS18B20_SCRPD_WR: Allows the master to write the 3 registers of the scratchpad memory.
DS18B20_SCRPD_RD: Allows the master to read the contents of the scratchpad.
DS18B20_EEPROM_RCL: Recalls the alarm trigger and configuration registers from the EEPROM to scratchpad memory.
DS18B20_PWR_RD: Reads power supply (externally or parasite-powered).

Function Documentation

ssize_t ds18b20_check_family_code ( uint8_t * rom )

Verifies that the family code stored in rom first byte belongs to the driver supported device. Data read is CRC8 checked before a success is reported.

Parameters

[in] rom address where ROM of device is stored.

Return values

0	on success.
<0	if there is any error.

ssize_t ds18b20_config	(	uint8_t *	rom,
		int8_t	th,
		int8_t	tl,
		uint8_t	resolution
	)

Configures resolution and alarm registers of a specific DS18B20.

Parameters

[in]	rom	address where ROM of device is stored. NULL if only one device is connected to the 1-Wire bus.
[in]	th	alarm High Register.
[in]	tl	alarm Low Register.
[in]	resolution	resolution to be configured (9, 10, 11 or 12 bits).

Return values

0	on success.
<0	if there is any error.

ssize_t ds18b20_eeprom_recall ( uint8_t * rom )

Restores data from permanent EEPROM (TH, TL and configuration registers) to scratchpad memory.

Parameters

[in] rom address where ROM of device is stored. NULL if only one device is connected to the 1-Wire bus.

Return values

0	on success.
<0	if there is any error.

ssize_t ds18b20_parasite_powered ( uint8_t * rom )

Checks wether the DS18B20 is parasite powered.

Parameters

[in] uint8_t *rom address where ROM of device is stored. NULL if only one device is connected to the 1-Wire bus.

Return values

0	if device is externally powered.
1	if device is parasite powered.
<0	if there is any error.

ssize_t ds18b20_read_temp	(	uint8_t *	rom,
		int16_t *	temperature
	)

Reads temperature registers from DS18B20. If device is parasite-powered a strong pull-up is necessary.

Parameters

[in]	rom	address where ROM of device is stored. NULL if only one device is connected to the 1-Wire bus.
[in]	temperature	buffer where read register will be stored.

Return values

0	on success.
<0	if there is any error.

ssize_t ds18b20_scratchpad_copy ( uint8_t * rom )

Copies data from scratchpad memory (TH, TL and configuration registers) to permanent EEPROM. If device is parasite-powered a strong pull-up is necessary.

Parameters

[in] rom address where ROM of device is stored. NULL if only one device is connected to the 1-Wire bus.

Return values

0	on success.
<0	if there is any error.

ssize_t ds18b20_scratchpad_read	(	uint8_t *	rom,
		uint8_t *	scratchpad
	)

Reads the content of scratchpad memory (temperature, triggers and configuration registers) from DS18B20. Data read is CRC8 checked before a success is reported.

Parameters

[in]	rom	address where ROM of device is stored. NULL if only one device is connected to the 1-Wire bus.
[in]	scratchpad	address where content of memory will be stored.

Return values

0	on success.
<0	if there is any error.

int16_t ds18b20_temp_conv ( uint8_t * temp_regs )

Performs a conversion of the temperature read from DS18B20.

Parameters

[in] temp_regs temperature registers (LSB and MSB).

Return values

signed value of temperature multiplied by 100 (2 less significative digits are decimals).

ssize_t ds1904_check_family_code ( uint8_t * rom )

Verifies that the family code stored in rom first byte belongs to the driver supported device. Data read is CRC8 checked before a success is reported.

Parameters

[in] rom address where ROM of device is stored.

Return values

0	on success.
<0	if there is any error.

Functions

Detailed Description

DS18B20 API Overview

DS18B20 Macros

Function Documentation