Temp Probe Click is based on the LTC2986, a high accuracy thermocouple temperature monitoring system with 0.1°C accuracy and 0.001°C resolution from Analog Devices. The LTC2986 simultaneously measures the thermocouple output and the cold junction temperature and performs all required calculations to report the thermocouple temperature in °C or °F. It combines high accuracy with the simple operation composed of five states: Start-Up, Channel Assignment, Initiate Conversion, Conversion, and Read Results. It works with ground-referenced sensors without the need for amplifiers, negative supplies, or level shift circuitry where signals are simultaneously digitized with three, high accuracy, 24-bit Δ-Σ ADCs using an internal 15ppm/°C reference.

Thermocouples can measure temperatures from –265°C to more than 1.800°C, generating a voltage as a function of the temperature difference between the tip (thermocouple temperature) and the electrical connection on the circuit board (cold junction temperature). In order to determine the thermocouple temperature, an accurate measurement of the cold junction temperature is required, known as cold junction compensation. The LTC2986 preforms automatic thermocouple cold junction compensation using any type of external sensor.

The onboard PCC-SMP connector is a perfect solution for bringing thermocouple probes to the PCB, suitable for all K-type probes. To use Temp Probe Click user needs to connect the appropriate K-type thermocouple probe, which is not included in the package, into the PCC-SMP connector. Type-K thermocouple with glass braid insulation, available in our store, is used for precision measurements of high temperatures allowing this Click board™ to measure temperature up to 480°C (900°F).

Temp Probe Click communicates with MCU using the SPI serial interface with a maximum SPI frequency of 2 MHz. The interrupt pin routed on the INT pin of the mikroBUS™ socket is utilized by LTC2986 to signal when the device is busy either during Start-Up or while a conversion cycle is in progress. Alongside this feature, this Click board™ also has a Reset function routed on the RST pin of the mikroBUS™ socket that will put the LTC2986 into the reset state by driving the RST pin LOW. Once this pin is returned HIGH, the device initiates its Start-Up sequence.

This Click board™ is designed to operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. It allows for both 3.3V and 5V capable MCUs to use the SPI communication lines properly. However, the Click board™ comes equipped with a library that contains easy to use functions and an example code which can be used, as a reference, for further development