MAX31855(9)

SYNOPSIS

loadrt max31855 [count=N|names=name1[,name2…]] [personality=P1[,P2…]]

DESCRIPTION

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

loadrt max31855 personality=1

setp hm2_6i25.0.gpio.023.is_output true
setp hm2_6i25.0.gpio.024.is_output true

net spi.clk.in    hm2_6i25.0.gpio.023.out     max31855.0.clk.out
net spi.cs.in     hm2_6i25.0.gpio.024.out     max31855.0.cs.out
net spi.data0.in  hm2_6i25.0.gpio.033.in_not  max31855.0.data.0.in

addf max31855.0.bitbang-spi servo-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.

FUNCTIONS

max31855.N.bitbang-spi

PINS

max31855.N.data.M.in bool in (M=0..personality & 0xf-1): Pin(s) connected to data out.
max31855.N.cs.out bool out: Pin connected to cs, pulled low to shift data, pulled high for data refresh.
max31855.N.clk.out bool out: Pin connected to clk.
max31855.N.temp-celsius.M real out (M=0..personality & 0xf-1): Temperature output values in Celsius.
max31855.N.temp-fahrenheit.M real out (M=0..personality & 0xf-1): Temperature in Fahrenheit.
max31855.N.temp-kelvin.M real out (M=0..personality & 0xf-1): Temperature in Kelvin.
max31855.N.fault.M bool out (M=0..personality & 0xf-1): Fault condition detected.
max31855.N.fault-flags.M uint out (M=0..personality & 0xf-1): Fault flags: 0x1 = open sensor, 0x2 short to gnd, 0x3 short to vcc.

AUTHOR

Joseph Calderon

LICENSE

GPL