Intending to enhance my generic heating / cooling controller to read SPI temperature sensors, I purchased an Adafruit MAX31855 module on eBay from a local supplier for about A$26 posted.
The module you might have guessed uses a MAX31855, a Cold-Junction Compensated Thermocouple-to-Digital Converter for K type thermocouple with an SPI interface. The Adafruit module includes a regulator and level translators to use it in a 5V system.
This article describes a simple checkout using a BusPirate V4. Conveniently, the MAX31855 module can be powered from the BusPirate. The thermocouple input is provided by a thermocouple calibrator.
After a short wait to allow both devices to stabilise at ambient temperature, a test was run. The BusPirate session is as follows. Continue reading Adafruit MAX31855 checkout