ESP32 thermocouple thermometer with an alarm: MAX6675 and OLED
Open in the lab ▸Make my own copy
A K-type thermocouple makes about 41 µV per °C and survives an oven or a kiln. The MAX6675 amplifies it, corrects for its own temperature and sends the reading over SPI; the ESP32 shows it on an OLED and sounds a buzzer at 250 °C. Unplug the thermocouple (click the module) and the screen says OPEN instead of a wrong number. Open it and press Run: the sketch is inside the board (click the board, then Code). Every part, pin and resistor matches what you would build on a real breadboard; the guided build of the same name has the test sheet and hidden faults.
What is on the bench
5 parts, 13 wires, with a sketch (the program runs in the lab). Boards: ESP32 DevKit.
| ESP32 DevKit | 1 |
|---|---|
| Bench power supply | 1 |
| MAX6675 thermocouple module | 1 |
| OLED display (I²C) | 1 |
| Active buzzer | 1 |
Put it on your page
The project runs live inside the frame: readers can press buttons, turn knobs and read the meters.
<iframe src="https://zencircuitlab.com/embed/zclctherm" width="100%" height="560" style="border:1px solid #2f363a;border-radius:10px" loading="lazy" title="ESP32 thermocouple thermometer with an alarm: MAX6675 and OLED on Zen Circuit Lab"></iframe>
Link
https://zencircuitlab.com/p/zclctherm
Published by its author under the lab's community terms: it may be opened, copied and changed by anyone. Simulation results are for learning; check a real build against the parts' datasheets.