max31855 - Support for the MAX31855 Thermocouple-to-Digital converter using bitbanged spi

       Joseph Calderon

       The component requires at least 3 pins to bitbang spi protocol, for example:

        loadrtmax31855personality=1setphm2_6i25.0.gpio.023.is_outputtruesetphm2_6i25.0.gpio.024.is_outputtruenetspi.clk.inhm2_6i25.0.gpio.023.outmax31855.0.clk.outnetspi.cs.inhm2_6i25.0.gpio.024.outmax31855.0.cs.outnetspi.data0.inhm2_6i25.0.gpio.033.in_notmax31855.0.data.0.inaddfmax31855.0.bitbang-spiservo-thread

       The  MAX31855  supports  a  range of -270C to 1800C, however linearization data is only available for the
       -200C to 1350C range, beyond which raw temperature is returned.

       Temperature pins are provided for readings in Celsius, Fahrenheit and Kelvin, temperature values are  not
       updated while a fault condition is present.

       The  personality parameter is used to indicate the number of sensors.  Multiple sensors share the clk and
       cs pins, but connect to discrete data input pins.  A maximum of 15 sensors are supported.

max31855.N.bitbang-spi (requires a floating-point thread)

       GPL

LinuxCNC Documentation                             2025-06-19                                        MAX31855(9)

       max31855 - Support for the MAX31855 Thermocouple-to-Digital converter using bitbanged spi

max31855.N.data.M.in bit in (M=0..( personality & 0xf ))
              Pin(s) connected to data out.

       max31855.N.cs.out bit out
              Pin connected to cs, pulled low to shift data, pulled high for data refresh.

       max31855.N.clk.out bit out
              Pin connected to clk.

       max31855.N.temp-celsius.M float out (M=0..( personality & 0xf ))
              Temperature output values in Celsius.

       max31855.N.temp-fahrenheit.M float out (M=0..( personality & 0xf ))
              Temperature in Fahrenheit.

       max31855.N.temp-kelvin.M float out (M=0..( personality & 0xf ))
              Temperature in Kelvin.

       max31855.N.fault.M bit out (M=0..( personality & 0xf ))
              Fault condition detected.

       max31855.N.fault-flags.M u32 out (M=0..( personality & 0xf ))
              Fault flags: 0x1  = open sensor, 0x2 short to gnd, 0x3 short to vcc.

loadrtmax31855[count=N|names=name1[,name2...]][personality=P1,P2,...]