Temperature Measurement Display on 16x2 LCD With Adjusting the Temperature Upper and Lower Limit for Warning Using Arduino




Hello everybody, here is my first project with Arduino. In this project, I will show you how to measure temperature and display it on a 16x2 LCD using Arduino , and we can use 2 button to choose what we want to see on LCD: Degrees Celsius or Fahrenheit .
I also add 2 leds into this circuit in order to warn us whenever the temperature value is lower or upper than the temperature limit we set. Leds will blink when it happens. The upper and lower limit can be adjusted with 2 resistor vars. I use LM35 sensor in this project. I won’t tell more about this sensor. We should find how to use it and see the datasheet of it.
Datasheets of LM35DZ, 16x2 LCD,…etc… can be downloaded from: http://www.alldatasheets.com/

Step 1: Material.

These are all the things we need in this project:
1x Arduino Uno (Or Nano is ok)
1x Breadboard
1x LM35DZ sensor
1x 16x2 LCD Compatible with Arduino
2x leds
2x buttons
2x 10k resistor
3x 10k Resistor Var (1 for adjusting  the brightness for LCD)

Step 2: Wire It Up

I designed this shematic and simulated it on Proteus. Let see the schematic below:

After simulating in Protues, we 'll make the real one on test board.

We’ll start with the LCD screen since it has the most pins:
Connect pins 1 and 5 to the Arduino’s GND. (Doesn’t matter which one)
Connect pin 2 to the Arduino’s +5v
Connect pin 3 to Resistor Var
Connect pin 4 to the Arduino’s Digital Pin 13
Connect pin 6 to the Arduino’s Digital Pin 12
Connect pin 11 to the Arduino’s Digital Pin 11
Connect pin 12 to the Arduino’s Digital Pin 10
Connect pin 13 to the Arduino’s Digital Pin 9
Connect pin 14 to the Arduino’s Digital Pin 8

LM35DZ sensor:
Connect pin 1 to the Arduino’s +5V
Connect pin 2 to the Arduino’s Analog Pin A0
Connect pin 3 to the Arduino’s GND

2 Resistor Var (for Adjusting Limit): 
Connect pin 1 each Resistor Var to the Arduino’s +5V
Connect pin 2 each Resistor Var to the Arduino’s Analog Pin A1 and  A2.
Connect pin 3 each to the Arduino’s GND

2 Mode Buttons:
Connect each button pin to the Arduino Uno’s interrupt pin 2 and 3
Connect each another button pin to each 10k Res and then connect it to the Arduino’s GND

Now we move to the last step.

Step 3: Connect and Code.

Connect the Arduino to your PC/Laptop. Download and Upload the sketch below. In case the link can’t be download, I’ve post here.


Step 4: Make a PCB If You Want. ^^

 You can make a printed circuit (PCB) like that to measure the temperature in your room or in your house…
I think it’s interesting.^^

This is my PCB:




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    11 Discussions


    2 years ago

    can i use a humidity senser?....bro


    4 years ago on Introduction

    Will this work using a different temperature sensor such as Labfacility DRG 010632B Sensor, Temperature, 100 ohm, class b?

    1 reply

    With different sensors, you need to know how it works. I think with each sensor, we must use different formula. So, my code may not work with the others. But with Arduino, I think re-programing is quite easy.


    4 years ago on Introduction

    Hi GieselleE, thanks for reading my Tutorial.

    I 've read some thread about Gizduino. It comes from your country huh? :v It is quite the same as Arduino. I found only the huge difference is about USB driver so I think it does not affect to the above Arduino code

    For installing USB driver for Gizduino, you can follow this installation guide: https://docs.google.com/file/d/0BxdLxDCD6HidMlQ2bm... It's quite easy.

    Good luck to you and your project.

    Greeting from Vietnam.


    4 years ago on Introduction

    Hi your project is very helpful since my group mates and I are also going to construct a temperature sensor similar to this although I have a question, can the program for the Arduino still work if we are going to use gizduino? It is not an original Arduino board, more like a clone one. Thank you for your response! :)


    Reply 5 years ago on Introduction

    hello ayerra, i 've post the link that u can download the code in step 3. please read carefully.