Posted 26 January 2018 by Yassine2 Comments Non classé

Simplest Arduino based thermometer using LM35 and LCD i2c screen

Hello there, this is an easy project to start with if you’re new to Arduino, this is my first project and pretty much my first contact with Arduino World.

It’s an easy thermometer, temperature sensor used with Arduino and a LCD i2c screen. It measures and shows the ambient temperature in °C.

The LM35z has a range of 0-100°C, linear, has an Analog output and can be used in all standard applications.

Wiring:

The wiring is easy as well, the sensor pins are VCC/OUT/GND are wired with respectively 5V/A0/GND.
A0 or any analog input will do the work, but don’t forget to modify the code.

The LCD i2c has 4 pins GND/VCC/SDA/SCL are wired respectively with GND/5V/A4/A5.

Libraries:

The only library I used is the LCD i²c New _liquid_crystal, you can use any library you want just adapt the functions.

In case you use a standard LCD you’ll need another library and suitable functions.

LCD i2c Library: Download library

Code:

Download the code here: Download .ino or:

//Arduino Thermometer using LM35DZ sensor with a LCD display 
//SurtrTech Youtube channel 

#include <Wire.h> //Libraries for I2C and LCD 
#include <LCD.h> 
#include <LiquidCrystal_I2C.h>
 
float temp; //Variable where we will stock the temperature value 
int tempPin = 0; //Pin used with the sensor output here it's A0 

#define I2C_ADDR 0x27 //I2C Adress 
#define BACKLIGHT_PIN 3 //LCD Stuffs :D 
#define En_pin 2 
#define Rw_pin 1 
#define Rs_pin 0 
#define D4_pin 4 
#define D5_pin 5 
#define D6_pin 6 
#define D7_pin 7 
LiquidCrystal_I2C lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin); 

void setup() {  

Serial.begin(9600);  
lcd.begin (16,2);  
lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);  
lcd.setBacklight(HIGH);  
lcd.home (); 
} 
void loop() {  

temp = analogRead(tempPin); //Reading the value from the analog input
temp = temp * 0.48828125; //Sensor calibration to get the real value 
lcd.clear(); 
lcd.setCursor (0,0); //Start writing on 0.0 on lcd screen
lcd.print("Temperature"); 
lcd.setCursor (0,1); 
lcd.print(temp); //Temperature value
lcd.print(" C"); //Celsius of course :D
delay(1000); //Refresh every 1s 
}

//Arduino Thermometer using LM35DZ sensor with a LCD display

//SurtrTech Youtube channel

#include <Wire.h> //Libraries for I2C and LCD

#include <LCD.h>

#include <LiquidCrystal_I2C.h>

float temp; //Variable where we will stock the temperature value

int tempPin = 0; //Pin used with the sensor output here it's A0

#define I2C_ADDR 0x27 //I2C Adress

#define BACKLIGHT_PIN 3 //LCD Stuffs :D

#define En_pin 2

#define Rw_pin 1

#define Rs_pin 0

#define D4_pin 4

#define D5_pin 5

#define D6_pin 6

#define D7_pin 7

LiquidCrystal_I2C lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);

void setup() {

Serial.begin(9600);

lcd.begin (16,2);

lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);

lcd.setBacklight(HIGH);

lcd.home ();

}

void loop() {

temp = analogRead(tempPin); //Reading the value from the analog input

temp = temp * 0.48828125; //Sensor calibration to get the real value

lcd.clear();

lcd.setCursor (0,0); //Start writing on 0.0 on lcd screen

lcd.print("Temperature");

lcd.setCursor (0,1);

lcd.print(temp); //Temperature value

lcd.print(" C"); //Celsius of course :D

delay(1000); //Refresh every 1s

}

Yassine View All

Automation and Electrical Engineer, Electronics amateur trying to share my little projects.

Good night;
Below is the correct Source Code, since the one on your Site contains some errors: