Adafruit_MAX31865 Class Reference

#include <Adafruit_MAX31865.h>

Public Member Functions
	Adafruit_MAX31865 (int8_t spi_cs, int8_t spi_mosi, int8_t spi_miso, int8_t spi_clk)
	Create the interface object using software (bitbang) SPI. More...
	Adafruit_MAX31865 (int8_t spi_cs, SPIClass *theSPI=&SPI)
	Create the interface object using hardware SPI. More...
bool	begin (max31865_numwires_t x=MAX31865_2WIRE)
	Initialize the SPI interface and set the number of RTD wires used. More...
uint8_t	readFault (max31865_fault_cycle_t fault_cycle=MAX31865_FAULT_AUTO)
	Read the raw 8-bit FAULTSTAT register. More...
void	clearFault (void)
	Clear all faults in FAULTSTAT.
uint16_t	readRTD ()
	Read the raw 16-bit value from the RTD_REG in one shot mode. More...
void	setThresholds (uint16_t lower, uint16_t upper)
	Write the lower and upper values into the threshold fault register to values as returned by readRTD() More...
uint16_t	getLowerThreshold (void)
	Read the raw 16-bit lower threshold value. More...
uint16_t	getUpperThreshold (void)
	Read the raw 16-bit lower threshold value. More...
void	setWires (max31865_numwires_t wires)
	How many wires we have in our RTD setup, can be MAX31865_2WIRE, MAX31865_3WIRE, or MAX31865_4WIRE. More...
void	autoConvert (bool b)
	Whether we want to have continuous conversions (50/60 Hz) More...
void	enable50Hz (bool b)
	Whether we want filter out 50Hz noise or 60Hz noise. More...
void	enableBias (bool b)
	Enable the bias voltage on the RTD sensor. More...
float	temperature (float RTDnominal, float refResistor)
	Read the temperature in C from the RTD through calculation of the resistance. Uses http://www.analog.com/media/en/technical-documentation/application-notes/AN709_0.pdf technique. More...
float	calculateTemperature (uint16_t RTDraw, float RTDnominal, float refResistor)
	Calculate the temperature in C from the RTD through calculation of the resistance. Uses http://www.analog.com/media/en/technical-documentation/application-notes/AN709_0.pdf technique. More...

Detailed Description

Interface class for the MAX31865 RTD Sensor reader

Constructor & Destructor Documentation

Adafruit_MAX31865() [1/2]

Adafruit_MAX31865::Adafruit_MAX31865	(	int8_t	spi_cs,
		int8_t	spi_mosi,
		int8_t	spi_miso,
		int8_t	spi_clk
	)

Create the interface object using software (bitbang) SPI.

Parameters

spi_cs	the SPI CS pin to use
spi_mosi	the SPI MOSI pin to use
spi_miso	the SPI MISO pin to use
spi_clk	the SPI clock pin to use

Adafruit_MAX31865() [2/2]

Adafruit_MAX31865::Adafruit_MAX31865	(	int8_t	spi_cs,
		SPIClass *	theSPI = &SPI
	)

Create the interface object using hardware SPI.

Parameters

spi_cs	the SPI chip select pin to use
theSPI	the SPI device to use, default is SPI

Member Function Documentation

begin()

bool Adafruit_MAX31865::begin

(

max31865_numwires_t

wires = MAX31865_2WIRE

)

Initialize the SPI interface and set the number of RTD wires used.

Parameters

wires

The number of wires in enum format. Can be MAX31865_2WIRE, MAX31865_3WIRE, or MAX31865_4WIRE

Returns

True

readFault()

uint8_t Adafruit_MAX31865::readFault

(

max31865_fault_cycle_t

fault_cycle = MAX31865_FAULT_AUTO

)

Read the raw 8-bit FAULTSTAT register.

Parameters

fault_cycle

The fault cycle type to run. Can be MAX31865_FAULT_NONE, MAX31865_FAULT_AUTO, MAX31865_FAULT_MANUAL_RUN, or MAX31865_FAULT_MANUAL_FINISH

Returns

The raw unsigned 8-bit FAULT status register

readRTD()

uint16_t Adafruit_MAX31865::readRTD

(

void

)

Read the raw 16-bit value from the RTD_REG in one shot mode.

Returns

The raw unsigned 16-bit value, NOT temperature!

setThresholds()

void Adafruit_MAX31865::setThresholds	(	uint16_t	lower,
		uint16_t	upper
	)

Write the lower and upper values into the threshold fault register to values as returned by readRTD()

Parameters

lower	raw lower threshold
upper	raw upper threshold

getLowerThreshold()

uint16_t Adafruit_MAX31865::getLowerThreshold

(

void

)

Read the raw 16-bit lower threshold value.

Returns

The raw unsigned 16-bit value, NOT temperature!

getUpperThreshold()

uint16_t Adafruit_MAX31865::getUpperThreshold

(

void

)

Read the raw 16-bit lower threshold value.

Returns

The raw unsigned 16-bit value, NOT temperature!

setWires()

void Adafruit_MAX31865::setWires

(

max31865_numwires_t

wires

)

How many wires we have in our RTD setup, can be MAX31865_2WIRE, MAX31865_3WIRE, or MAX31865_4WIRE.

Parameters

wires

The number of wires in enum format

autoConvert()

void Adafruit_MAX31865::autoConvert

(

bool

b

)

Whether we want to have continuous conversions (50/60 Hz)

Parameters

b	If true, auto conversion is enabled

enable50Hz()

void Adafruit_MAX31865::enable50Hz

(

bool

b

)

Whether we want filter out 50Hz noise or 60Hz noise.

Parameters

b	If true, 50Hz noise is filtered, else 60Hz(default)

enableBias()

void Adafruit_MAX31865::enableBias

(

bool

b

)

Enable the bias voltage on the RTD sensor.

Parameters

b	If true bias is enabled, else disabled

temperature()

float Adafruit_MAX31865::temperature	(	float	RTDnominal,
		float	refResistor
	)

Read the temperature in C from the RTD through calculation of the resistance. Uses http://www.analog.com/media/en/technical-documentation/application-notes/AN709_0.pdf technique.

Parameters

RTDnominal	The 'nominal' resistance of the RTD sensor, usually 100 or 1000
refResistor	The value of the matching reference resistor, usually 430 or 4300

Returns

Temperature in C

calculateTemperature()

float Adafruit_MAX31865::calculateTemperature	(	uint16_t	RTDraw,
		float	RTDnominal,
		float	refResistor
	)

Calculate the temperature in C from the RTD through calculation of the resistance. Uses http://www.analog.com/media/en/technical-documentation/application-notes/AN709_0.pdf technique.

Parameters

RTDraw	The raw 16-bit value from the RTD_REG
RTDnominal	The 'nominal' resistance of the RTD sensor, usually 100 or 1000
refResistor	The value of the matching reference resistor, usually 430 or 4300

Returns

Temperature in C

---

The documentation for this class was generated from the following files:

• Adafruit_MAX31865.h
• Adafruit_MAX31865.cpp