# Arduino Thermometer

34,293

289

23

## Introduction: Arduino Thermometer

Its hot here in Los Angeles! Besides the massive drought California is in, Its not as cool around here lately. I wanted to build something to see just how hot it really was, and here it is!

Read this instructable and Ill teach how you can turn just a few components you have into an accurate mini desktop thermometer!

I hope you enjoy the project and vote for it for the contests!

Lets Build It!

### Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

## Step 1: You Will Need...

If you would like to make this project, you will need:

2. Plastic Tupperware (Free)

As you can see, you dont need much. In fact I had these pieces lying around my house so this was FREE!

## Step 2: Test the LCD

I wanted to test and see if my LCD still worked. It still worked! Heres how I wired it:

LCD Arduino

1...... GDN

2...... 5V

3...... GDN

4...... PIN 8

5...... GDN

6...... PIN 9

7...... –

8....... –

9...... –

10...... –

11...... PIN 4

12......PIN 5

13......PIN 6

14...... PIN 7

15...... 5V

16...... GDN

## Step 3: Add in the LM35!

(Ignore the periods)

____________

[ LM35 (Front) ]

[...................... ]

[___________]

I............I...........I

I............I...........I

I............I.......... I

(5v)....(A0).....(GDN)

## Step 4: Check Your Wiring

Make sure to double check your wiring!

We don't want any mistakes!

Heres a schematic I used for this project

## Step 5: Code!

Now its time to code!

Here the code! (Please If you see anything wrong tell me)

```
//----------------------------------------------------------------
//     Program:     LCD_temperature

//----------------------------------------------------------------
#include

// Arduino pins used for LCD
LiquidCrystal lcd(8,9,4,5,6,7);

void setup() {
lcd.begin(16, 2);
}

void loop() {
float temperature = 0.0;   // stores the calculated temperature
int sample;                // counts through ADC samples
float ten_samples = 0.0;   // stores sum of 10 samples

for (sample = 0; sample < 10; sample++) {
// convert A0 value to temperature
temperature = ((float)analogRead(A0) * 5.0 / 1024.0) - 0.5;
temperature = temperature / 0.01;
// sample every 0.1 seconds
delay(100);
// sum of all samples
ten_samples = ten_samples + temperature;
}
// get the average value of 10 temperatures
temperature = ten_samples / 10.0;
// display the temperature on the LCD
lcd.setCursor(0, 0);
lcd.print("Temperature:");
lcd.setCursor (0,1);
lcd.print (temperature);
lcd.print((char)223);
lcd.print(" F ");
ten_samples = 0.0;
}

```

## Step 6: Measure LCD

Now its time to make the case

Measure the LCD protruding sceen and cut a hole just big enough to squeeze over the LCD.

Saftly place all the electronics in the plastic container and snap the lid on!

Place your thermometer near your bed like I did, whenever I wake up, I can see how hot it is!

Please Like Comment And Subscribe for more!

Participated in the
Coded Creations

Participated in the
Hot Glue Challenge

128 5.6K
2 259
36 10K

## 23 Discussions

Nice instructable, it didn't work the first try, problem: LCD characters were displayed as white cubes just like our friend @VictorG9 case, I'm going to check

https://www.instructables.com/id/How-to-use-an-LCD...

since my guess is that the problem is with the contrast settings of the LCD and it would be solved by a potentiometer.

It doesn't work, why? :'( I've checked 3 times the wires

be sure that you are using the correct pins for the lcd.

when it does this that means that u should change the pins

First, you need a potentiometer to regulate the contrast on screen if you still having troubles, check if you add the library of the Lm35, if you want some help with the code send me a msg we'll find it out, good day!

Usually you need to add a variable resistor and connect its output to the contrast pin which is the 3rd pin from the left. Google "liquidcrystal arduino". Hope that helps

my lcd doesnt have a character

This looks clean. I like it.

Can you tell how long a batterij lasts?

So I made this and used your code and the only thing that displays is 3 zeros on one side of the screen and 2 on the other? What happened.