Connecting the MCP9600 to your Feather or Metro / Arduino is easy:

  • If you are running a Feather (3.3V), connect Feather 3V to board VIN
  • If you are running a 5V Arduino (Uno, etc.), connect Arduino 5V to board VIN
  • Connect Feather or Arduino GND to board GND
  • Connect Feather or Arduino SCL to board SCL
  • Connect Feather or Arduino SDA to board SDA
  • Connect thermocouple + to board screw terminal +
  • Connect thermocouple - to board screw terminal -

The final results should resemble the illustration above, showing an Adafruit Metro development board.

The MCP9600 will return a temperature for the hot junction even if there is no thermocouple connected. There will not be an error!


You can install the Adafruit MCP9600 Library for Arduino using the Library Manager in the Arduino IDE:

Click the Manage Libraries ... menu item, search for Adafruit MCP9600, and select the Adafruit MCP9600 library:

Also get the Adafruit BusIO library

Load Example

Open up File -> Examples -> Adafruit MCP9600 -> mcp9600_test and upload to your Arduino wired up to the sensor.

Upload the sketch to your board and open up the Serial Monitor (Tools->Serial Monitor). You should see the the values for hot junction, cold junction and ADC.

Example Code

The following example code is part of the standard library, but illustrates how you can retrieve sensor data from the MCP9600 for the hot junction, cold junction and ADC values:

#include <Wire.h>
#include <Adafruit_I2CDevice.h>
#include <Adafruit_I2CRegister.h>
#include "Adafruit_MCP9600.h"

#define I2C_ADDRESS (0x67)

Adafruit_MCP9600 mcp;

void setup()
    while (!Serial) {
    Serial.println("MCP9600 HW test");

    /* Initialise the driver with I2C_ADDRESS and the default I2C bus. */
    if (! mcp.begin(I2C_ADDRESS)) {
        Serial.println("Sensor not found. Check wiring!");
        while (1);

  Serial.println("Found MCP9600!");

  Serial.print("ADC resolution set to ");
  switch (mcp.getADCresolution()) {
    case MCP9600_ADCRESOLUTION_18:   Serial.print("18"); break;
    case MCP9600_ADCRESOLUTION_16:   Serial.print("16"); break;
    case MCP9600_ADCRESOLUTION_14:   Serial.print("14"); break;
    case MCP9600_ADCRESOLUTION_12:   Serial.print("12"); break;
  Serial.println(" bits");

  Serial.print("Thermocouple type set to ");
  switch (mcp.getThermocoupleType()) {
    case MCP9600_TYPE_K:  Serial.print("K"); break;
    case MCP9600_TYPE_J:  Serial.print("J"); break;
    case MCP9600_TYPE_T:  Serial.print("T"); break;
    case MCP9600_TYPE_N:  Serial.print("N"); break;
    case MCP9600_TYPE_S:  Serial.print("S"); break;
    case MCP9600_TYPE_E:  Serial.print("E"); break;
    case MCP9600_TYPE_B:  Serial.print("B"); break;
    case MCP9600_TYPE_R:  Serial.print("R"); break;
  Serial.println(" type");

  Serial.print("Filter coefficient value set to: ");

  mcp.setAlertTemperature(1, 30);
  Serial.print("Alert #1 temperature set to ");
  mcp.configureAlert(1, true, true);  // alert 1 enabled, rising temp



void loop()
  Serial.print("Hot Junction: "); Serial.println(mcp.readThermocouple());
  Serial.print("Cold Junction: "); Serial.println(mcp.readAmbient());
  Serial.print("ADC: "); Serial.print(mcp.readADC() * 2); Serial.println(" uV");

You should get something resembling the following output when you open the Serial Monitor at 115200 baud:

Note: The image above shows 9600 baud in the serial monitor. It should be 115200 to match the code!

This guide was first published on Jun 12, 2019. It was last updated on Apr 14, 2024.

This page (Arduino) was last updated on Apr 14, 2024.

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