SparkFun
SparkFun Thermocouple Breakout - MAX31855K
The SparkFun MAX31855K Thermocouple Breakout is a simple 14-bit resolution, SPI-compatible, serial interface thermocouple digitizer that makes reading a w...
The SparkFun MAX31855K Thermocouple Breakout is a simple 14-bit resolution, SPI-compatible, serial interface thermocouple digitizer that makes reading a wide range of temperatures possible. A thermocouple works by taking two wires made of dissimilar metals, connecting them at the two ends, and making a temperature gradient between one end and the other (a ‘hot’ end and a ‘cold’ one). Once this is achieved, a voltage potential is formed and current flows. The SparkFun Thermocouple Breakout takes a standard Type-K thermocouple in one end, digitizes the temperature measured and sends that data out the other end via a SPI interface, thereby interpreting the data and translating it for you to read!
With the SparkFun Thermocouple Breakout, the thermocouple’s hot junction can be read from -200°C to +700°C with an accuracy of ±2°C while the cold junction, inside the MAX31855K, can only range from -20°C to +85°C while maintaining ±2°C accuracy. The MAX31855K constantly measures the temperature of the cold junction using an internal temperature-sensing diode. The MAX31855K requires a power source from +3.0V to +3.6V (+3.0V nominal) and only draws 1.5mA maximum.
The Thermocouple Breakout is designed to accept a standard thermocouple connector, for convenience and compatibility with probes you may already own. These connectors aren’t necessary, and you could solder a thermocouple directly into the through-holes labeled ‘+’ and ‘-’. If you decide to solder the thermocouple directly to the breakout board, it is recommended that the thermocouple be mounted for strain relief to avoid breaking the thin wires. Notches for a zip-tie or wire wrapping have been provided in the PCB opposite the header for this purpose.
Features:
- 14-bit Resolution
- SPI-Compatible, Serial Interface
- -200°C to +700°C Temperature Reading with ±2°C Accuracy
- 3.0V to 3.6V (+3.0V nominal) Required
- Accepts Type-K Thermocouple
Documents:
- Schematic
- Eagle Files
- Hookup Guide
- Datasheet (MAX31855K)
- GitHub (Design Files)
- GitHub (Library & Example Code)
Jargon buster
Plain-language definitions for the technical terms used above.
- breakout
- A breakout is a small circuit board that makes a tiny or hard-to-solder component easier to connect to with standard pins. It matters because this OLED module can be wired into a microcontroller project without needing to solder directly to the display’s fine contacts.
- PCB
- A printed circuit board is a rigid board with copper tracks that connect electronic parts without loose wires. For this kit, the PCBs also form the airplane shape, so they are both the circuit base and part of the finished model.
- SPI
- A fast serial communication bus often used for displays, memory cards, and sensors. It matters because SPI devices need specific pins for clock and data, plus a separate chip-select line for each device.
- Thermocouple
- A temperature sensor made from two different metals that produces a very small voltage depending on temperature. Because the signal is tiny, it usually needs careful amplification and accurate measurement hardware.
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Brands
SparkFun Thermocouple Breakout Schematic
Schematic · 126.0 KB · Click any page to view full size
MAX31855K Datasheet
Datasheet · 991.9 KB · Click any page to view full size
Supplier page — sparkfun.com
Supplier Description · 739.7 KB · Click any page to view full size
Resources & Downloads
Guides, code examples, and more
Related Tutorials
Free guides on learn.littlebird.com.au
