Digital Thermometer with LCD: A Beginner Project

This is one of the first projects every Arduino enthusiast should build. It teaches you about sensors, displays, and basic coding.

Components

• Arduino Uno
• LM35 or DS18B20 Temperature Sensor
• 16x2 I2C LCD Display (or standard LCD + potentiometer)
• Breadboard & Wires

Sensor Options

| Sensor | Type | Range | Accuracy | | :--- | :--- | :--- | :--- | | LM35 | Analog | -55 to 150°C | ±0.5°C | | DS18B20 | Digital (1-Wire) | -55 to 125°C | ±0.5°C |

The DS18B20 is more accurate and can be chained (multiple sensors on one wire), but requires a library.

Circuit (LM35 Example)

• LM35 VCC → 5V
• LM35 GND → GND
• LM35 OUT → A0

Code Snippet

```cpp #include <LiquidCrystal_I2C.h> LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() { lcd.init(); lcd.backlight(); }

void loop() { int reading = analogRead(A0); float voltage = reading * (5.0 / 1024.0); float tempC = voltage * 100; // LM35: 10mV per degree C

lcd.setCursor(0, 0); lcd.print("Temp: "); lcd.print(tempC); lcd.print(" C"); delay(500); } ```

Upgrade Ideas

• Add a buzzer for high-temperature alerts.
• Log data to an SD card.
• Make it wireless with ESP32.

Our Kit

Build this project with the Digital Thermometer with LCD Display kit!