Raspberry Pi driver for MAX31855 Cold-Junction Compensated Thermocouple-to-Digital Converter
Python

README.md

Python driver for MAX31855 Cold-Junction Compensated Thermocouple-to-Digital Converter

Requires:

Basic use

#!/usr/bin/python
from max31855 import MAX31855, MAX31855Error

cs_pin = 24
clock_pin = 23
data_pin = 22
units = "f"
thermocouple = MAX31855(cs_pin, clock_pin, data_pin, units)
print(thermocouple.get())
thermocouple.cleanup()

Note: these are the GPIO pin numbers, not the header pin numbers.
This can be overriden by passing GPIO.BOARD as the fifth init parameter.

See max31855.py for a multi-chip example.

Changelog

V2.0

  • SPI now done in software
    • Use whatever pins you want for CS, Clock & Data
    • Hardware SPI was limited to only two chip / slave select lines.
      Now use as many chips a you have extra pins!
  • Removed quick2wire dependency.
  • Removed bitstring dependency; bit extraction and two's complement conversion now done in library.
  • Added cleanup() method to be called on close (or destruction of instance), which does a targeted version of GPIO.cleanup().

NOTE: If you were using the previous hardware-based version, you will have to update your code to match the new init function: MAX31855(cs_pin, clock_pin, data_pin, units)

V1.0

  • Initial release.