MAX6675 K-Type Thermocouple Sensor Module, SPI, up to 800C

Measuring temperatures well beyond what a standard NTC thermistor or digital temperature IC can handle calls for a thermocouple, and the MAX6675 is the dedicated chip that makes reading one straightforward from a microcontroller - taking a K-type thermocouple's raw millivolt-level signal and converting it into a clean, ready-to-read 12-bit digital value over a simple SPI interface.

Measurement range extends from -2C up to a genuinely high 800C, with 0.25C resolution and accuracy rated at 1.5C across that range - solid precision for a chip covering such a wide temperature span. Internal cold-junction compensation handles a detail that trips up naive thermocouple designs: a thermocouple's output depends on the temperature difference between its measuring tip and the connection point at the circuit board, so the MAX6675 automatically corrects for the board's own ambient temperature rather than requiring the builder to account for it manually in firmware.

Thermocouple break detection is a genuinely valuable safety and reliability feature: if the thermocouple wire breaks or becomes disconnected, the chip flags this condition rather than silently returning a plausible-looking but wrong reading - important for any application where a broken sensor silently returning a stale, falsely safe-looking temperature could have real consequences (an oven, a kiln, a 3D printer hotend). The chip also includes 2000V ESD protection on its inputs, helpful given thermocouples often run cabling into higher-temperature, higher-interference environments.

Builders working on a kiln or oven controller, a 3D printer hotend temperature readout, an industrial process monitoring project, or any application needing genuinely high-temperature measurement beyond what a basic thermistor can handle will find the MAX6675 a well-proven, extensively documented module for that specific job.