Arduino project · Temperature and climate · Medium
Non-Contact Thermometer with LCD
Point the sensor at an object to read its temperature without touching it. The red LED lights above 38 degrees C.
What you will learn
- How infrared thermometers work
- Why not touching is useful
- How to avoid wrong readings
How it works
The MLX90614 reads heat rays from the object. The LCD shows the temperature and the LED warns above 38 degrees. Not for medical use.
Try this next
- Add a buzzer.
- Use it to find hot spots on a motor.
- Show ambient temperature too.
The simulator program and explanation on this page are original. The idea follows a classic Arduino project that students have built for years.
Parts: sensors and actuators (tap to show or hide)
Try the inputs (virtual sensors)
Pins (you can change them)
| Part | Arduino pin (change it here) | How to wire it |
|---|
Every wire, one by one
Red rail = 5 V from the Arduino 5V pin. Black rail = GND. The coloured wires carry signals. Match the wire colours on the drawing to this list.
| # | Colour | From (part and leg) | To |
|---|
Steps run from top to bottom, then start again. While the simulation runs, the active step is highlighted in green.
Quantities come from the parts you added. The store links open a search for that item on Robu.in, Amazon.in and ThinkRobotics, so you always see what is in stock today. Check the model, voltage and price before you order.
| # | Item | Qty | Search term | Buy / compare |
|---|
The PDF has the circuit sketch, pin table, every wire, sequence, full code, the parts list with store links, do’s and don’ts for each part, and the safety notes. The project file lets you come back and keep editing.
In the real world
A non-contact thermometer
Point at a forehead or a cup. The needle shows the temperature without touching.
Tip: use the gold tab at the bottom of the circuit drawing to pull the real-world view up over the Arduino board. Your parts stay visible above it, so you can press a button and watch the real scene react.
- IR temperature sensor = the target temperature
- Red LED = fever warning