Introduction: Arduino LM35 Digital Temperature Meter

Hi Guys,

I have made a temperature meter for environmental temperature measurements using Arduino.

This is an anlaog temperature meter and I tried measuring the temperature of flame (up to some level), and also tried out the temperature of Ice as well.

For more detailed DIY experience about the project, check out my video below.

(The sponsors of the video is JLCPCB, Leading PCB manufacturing company from China, where I got my PCB design manufactured. you can find them here: You may make a PCB board, or use a dot board or bread board depending on your preferences.)

Step 1: Things You Need

Here are the things you need:

1. LM35 temperature sensor

2. 16x2 LCD display + I2C module

3. Arduino programming board

4. Enclosure.

5. Jumper wires etc.

Step 2: Connection

Hopefully LM35 connection is pretty simple. Here you go:

LM35 has 3 pins. From Left to write:

1. 1st pin - VCC - Connect to Arduino 5V pin

2. 2nd pin - Data - Connect to Arduino Analog pin 2

3. 3rd pin - GND - Connect to Arduino Ground pin

Now connect LCD + I2C module to Arduino. I2C module has got 4 wires:

VCC - Arduino 5V pin

GND - Arduino ground pin

SDA - Analog Pin A4 of Arduino nano (if you are using some other arduino board, the pin may change. Google it in such a case).

SCL- Analog Pin A5 of Arduino nano (if you are using some other arduino board, the pin may change. Google it in such a case).

Step 3: I2C Error Handling and Coding

Please find the coding in below link:

Some people may have issues with the I2C + LCD display. It is because of the different versions of the I2C module. In my case, I have used a library and set up the stuffs for I2C module. The library link is given:

Also refer the video for error fixing your I2C module:


Even some new I2C versions may not support the library. In such case, you have to first find our the related library, and fix your I2C+LCD display to working. Then you have to modify the I2C part of my coding. that would require some skills, But can be done successfully!!!

Step 4: Upload and Demonstration

If you have followed the above steps, All fine.

Once uploaded, you can now fix the system inside the enclosure and measure the temperature values using the portable device.

Please note the measurable range of temperature using LM35 is (-55 to 155) degree celcius.

For a more detailed explanation check out my video with demonstration!!!

Good Luck!!! :)