MAX31865 Struct Reference

Implementation of MAX31865 based temperature sensor. More...

#include <MAX31865.h>

Inherits SPI::Device.

Collaboration diagram for MAX31865:

Classes
struct	Config
	Sensor configuration. More...

Public Types
enum	Type { PT2WIRE = 0 , PT3WIRE = 1 , PT4WIRE = 0 }
	Sensor Type. More...

Public Member Functions
	MAX31865 (Sink< SPI::Request > &bus, DIO cs, Config c={ .wires=PT2WIRE,.Rnom=100,.Rref=430, })
	configure temperature sensor
double	tempLin ()
	linear temperature approximation
double	temp ()
	quadratic temperature approximation
void	sense ()
	async read temperature data from sensor
void	readFault ()
	async read fault data from sensor
void	readAllData ()
	async read all data from sensor
void	callback (const SPI::Request rq) override
	is called as soon as requested data arrived over wire
uint8_t	fault ()
void	clearFaults ()
	clear faults on sensor
void	setLThr (uint16_t thr)
	set low fault threshold value
void	setHThr (uint16_t thr)
	set high fault threshold value
void	select (bool sel)
	chipselect activation

Public Attributes
DIO	cs
	GPIO chipselect line.
struct SPI::Device::Conf	conf
	necessary SPI configuration

Detailed Description

Implementation of MAX31865 based temperature sensor.

supports 2 to 4 wire sensors of arbitrary nominal resistances, and arbitrary reference resistors.

Warning

reference resistor must be greater than sensor resistor (for platinum based resistors Rref = 4 * Rnom works best)

implemented only for temperatures > 0 degrees C. see https://analog.com/media/en/technical-documentation/application-notes/AN709_0.pdf for details

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Class Documentation

MAX31865::Config

struct MAX31865::Config

Sensor configuration.

Class Members
Type	wires	number of wires
double	Rnom	nominal resistance
double	Rref	reference resistor

Member Enumeration Documentation

Type

enum MAX31865::Type

Sensor Type.

Enumerator
PT2WIRE	2 wire
PT3WIRE	3 wire
PT4WIRE	4 wire

Constructor & Destructor Documentation

MAX31865()

MAX31865::MAX31865 ( Sink< SPI::Request > &  bus, DIO  cs, Config  c = { .wires = PT2WIRE, .Rnom = 100, .Rref = 430, }  )

inline

configure temperature sensor

Parameters

bus	SPI request queue
cs	Digital In/Out pin of chip select line
c	Hardware configuration of sensor

configures sensor for auto conversion with 50Hz filter

Member Function Documentation

tempLin()

double MAX31865::tempLin ( )

inline

linear temperature approximation

Returns

temperature in °C, NAN if sensor fault

temp()

double MAX31865::temp ( )

inline

quadratic temperature approximation

Returns

temperature in °C, NAN if sensor fault

fault()

uint8_t MAX31865::fault ( )

inline

Returns

fault byte read from sensor

setLThr()

void MAX31865::setLThr ( uint16_t  thr )

inline

set low fault threshold value

Parameters

thr

threshold

setHThr()

void MAX31865::setHThr ( uint16_t  thr )

inline

set high fault threshold value

Parameters

thr

threshold

select()

void SPI::Device::select ( bool  sel )

inlineinherited

chipselect activation

Parameters

sel	true/false

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The documentation for this struct was generated from the following file:

• dev/MAX31865.h