SENSORS/ACTUATORS

INTERNET OF THING (IoT)

Arduino - WiFi

LIBRARIES

Arduino - Temperature Sensor - LCD

Hardware Required

1	×	Arduino UNO or Genuino UNO
1	×	USB 2.0 cable type A/B
1	×	LCD I2C
1	×	Temperature Sensor DS18B20
1	×	Jumper Wires
1	×	(Optional) 9V Power Adapter for Arduino
1	×	(Optional) Screw Terminal Block Shield for Arduino

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About Temperature Sensor and LCD

If you do not know about temperature sensor and LCD (pinout, how it works, how to program ...), learn about them in the following tutorials:

Wiring Diagram

Wiring diagram

This image is created using Fritzing. Click to enlarge image

Real wiring

This image is created using Fritzing. Click to enlarge image

We suggest purchasing a DS18B20 sensor that comes with a wiring adapter for easy connection. The adapter has a built-in resistor, eliminating the need for a separate one in the wiring.

Arduino Code

/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-temperature-sensor-lcd */ #include <OneWire.h> #include <DallasTemperature.h> #include <LiquidCrystal_I2C.h> const int SENSOR_PIN = 13; // Arduino pin connected to DS18B20 sensor's DQ pin OneWire oneWire(SENSOR_PIN); // setup a oneWire instance DallasTemperature sensors(&oneWire); // pass oneWire to DallasTemperature library LiquidCrystal_I2C lcd(0x3F, 16, 2); // I2C address 0x27, 16 column and 2 rows float tempCelsius; // temperature in Celsius float tempFahrenheit; // temperature in Fahrenheit void setup() { sensors.begin(); // initialize the sensor lcd.init(); // initialize the lcd lcd.backlight(); // open the backlight } void loop() { sensors.requestTemperatures(); // send the command to get temperatures tempCelsius = sensors.getTempCByIndex(0); // read temperature in Celsius tempFahrenheit = tempCelsius * 9 / 5 + 32; // convert Celsius to Fahrenheit lcd.clear(); lcd.setCursor(0, 0); // start to print at the first row lcd.print(tempCelsius); // print the temperature in Celsius lcd.print((char)223); // print ° character lcd.print("C"); lcd.setCursor(0, 1); // start to print at the second row lcd.print(tempFahrenheit); // print the temperature in Fahrenheit lcd.print((char)223); // print ° character lcd.print("F"); delay(500); }

※ NOTE THAT:

The I2C address of LCD can vary according to the manufacturers. In the code, we used 0x27 that is specified by DIYables manufacturer

Quick Steps

Connect Arduino to PC via USB cable
Open Arduino IDE, select the right board and port

On Arduino IDE, Go to Tools Manage Libraries

Search “OneWire”, then find the OneWire library by Paul Stoffregen
Click Install button to install OneWire library.

Search “Dallas”, then find the DallasTemperature library by Miles Burton.
Click Install button to install DallasTemperature library.

Search “LiquidCrystal I2C”, then find the LiquidCrystal_I2C library by Frank de Brabander
Click Install button to install LiquidCrystal_I2C library.

Copy the above code and open with Arduino IDE
Click Upload button on Arduino IDE to upload code to Arduino

Put the sensor on hot and cold water, or grasp the sensor by your hand
See the result in LCD

This image is created using Fritzing. Click to enlarge image

If LCD displays nothing, see Troubleshooting on LCD I2C

Code Explanation

Read the line-by-line explanation in comment lines of source code!

Video Tutorial

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Temperature Sensor and LCD on Commercial Products

Medical Thermometer

The Best Arduino Starter Kit

See the best Arduino kit for beginner

Arduino - Temperature Sensor - LCD

Hardware Required

About Temperature Sensor and LCD

Wiring Diagram

Arduino Code

Quick Steps

Code Explanation

Video Tutorial

Temperature Sensor and LCD on Commercial Products

The Best Arduino Starter Kit

See Also