MAX31855 on a Pico W

[ctimmer]

I'm getting some strange temperature readings from the MAX31855. When I start the read loop it returns an expected room temperature reading. After grabbing the sensor the temperature reading drops. When the sensor is dipped in ice water the temperature reading rises.

Could some connections be hooked up backwards? Maybe an integer byte order problem? I'm stumped.

Here is my setup:

spi = machine.SPI(0, baudrate=5000000, polarity=0, phase=0)
cs = machine.Pin(17 , machine.Pin.OUT)

Thanks for your help,
Curt

Start up readings:
MAX31855 Return Values
Thermo Sign....  0
Thermo Temp....  95
Fault..........  False
Internal Sign..  0
Internal Temp..  374
Short to Vcc...  False
Short to GND...  False
Open Circuit...  False
Temp C.........  23.75
Temp F.........  74.75
Byte Array Hex.  b'017c1760'
Byte Array Bits  0000 0001 0111 1100 0001 0111 0110 0000

After I grab the sensor (Note: I am not a Zombie):
MAX31855 Return Values
Thermo Sign....  0
Thermo Temp....  57
Fault..........  False
Internal Sign..  0
Internal Temp..  375
Short to Vcc...  False
Short to GND...  False
Open Circuit...  False
Temp C.........  14.25
Temp F.........  57.65
Byte Array Hex.  b'00e41770'
Byte Array Bits  0000 0000 1110 0100 0001 0111 0111 0000

After dipping the sensor in ice water:
MAX31855 Return Values
Thermo Sign....  0
Thermo Temp....  159
Fault..........  False
Internal Sign..  0
Internal Temp..  371
Short to Vcc...  False
Short to GND...  False
Open Circuit...  False
Temp C.........  39.75
Temp F.........  103.55
Byte Array Hex.  b'027c1730'
Byte Array Bits  0000 0010 0111 1100 0001 0111 0011 0000