max31855

Documentation

Overview

The max31855 package interfaces with the Maxim Integrated MAX31855 thermocouple to digital converter chip.

The MAX31855 chip contains an analog-to-digital converter that is designed to read the low voltages produced by thermocouples and convert them to degrees centigrate which can be read out using a read-only SPI interface. The MAX31855 comes in a number of variants for the different types of thermocouples (max31855K for K-type, max31855J for J-type, etc).

The max31855 itself contains a temperature sensor, which is required to perform the temperature conversion and it is important to keep the junction between the thermocouple wires and the copper traces leading to the max31855 and the max31855 itself at the same temperature.

The max31855 measures the thermocouple temperature to a resolution of 0.25°C and its internal temperature to 0.0625°C. The absolute accuracy, however, is +/-2°C for K-type thermocouples in the -200°C..700°C range as well as for the internal temperature sensor.

Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31855.pdf

Index

• type Dev
  • func New(s spi.Conn) (*Dev, error)
  • func (d *Dev) Temperature() (devices.Celsius, devices.Celsius, error)

Types

type Dev

type Dev struct {
	// contains filtered or unexported fields
}

Dev represents a MAX31855 device.

func New

func New(s spi.Conn) (*Dev, error)

New returns a

func (*Dev) Temperature

func (d *Dev) Temperature() (devices.Celsius, devices.Celsius, error)

Temperature returns the themocouple temperature and the internal MAX31855 temperature (in that order).