Using a MAX6675 K-Type Thermocouple with Relay and Display

Using a MAX6675 K-Type Thermocouple with Relay and Display

This project demonstrates how to interface a MAX6675 K-type thermocouple with an Arduino, incorporating a relay for control and a display for temperature readings. This setup is invaluable for various applications where precise temperature monitoring and automated responses are needed. Here are some project ideas:

Overheat protection for sensitive electronics
Temperature-controlled incubator for biological experiments
Automated brewing system for coffee or beer
Industrial process monitoring and control
Environmental monitoring in a greenhouse or other controlled environment

Hardware/Components

To build this project, you will need the following components:

Arduino Uno (or compatible board)
MAX6675 K-type thermocouple module (in video at 00:58)
Relay module
TM1637 4-digit LED display module
Jumper wires
Connecting wires

Wiring Guide

The wiring is explained in the video (in video at 05:36). The specific connections depend on whether you are using a surface mount chip or a PCB module. Refer to the video for a detailed wiring diagram.

Arduino wiring for MAX6675 Thermocoupler module

Code Explanation

The Arduino code uses the MAX6675 library to read temperature values from the thermocouple. The key configurable parts of the code are:

Thermocouple pin definitions: thermoDO, thermoCS, and thermoCLK (in video at [03:53]). These pins need to be adjusted according to your wiring scheme.
Relay control pin: Pin 10 is used to control the relay (in video at [05:36]). Change this if needed.
Display configuration (if used): The code includes sections for configuring the TM1637 display. Adjust the CLK and DIO pins if necessary (in video at [03:53]).

The code includes functions to read temperature in Celsius and Fahrenheit. A crucial part of the code is the conditional statement that checks if the temperature exceeds a threshold (80.0°C in this example). If it does, the relay is activated (pin 10 goes LOW).


// If temperature goes above 80.0C, turn the relay ON
if(thermocouple.readCelsius() > 80.00){
  digitalWrite(10, LOW);// Set pin 10 LOW
} else {
  digitalWrite(10, HIGH);// Set pin 10 HIGH
}

Live Project/Demonstration

The video demonstrates the project in action (in video at 06:59). The sensor accurately reads the ambient temperature and increases when heated. The relay functionality is also showcased.