Beginner Guide to Using LCD 1602 I2C with Arduino UNO

LCD 1602 I2C is one of the most popular display modules used in Arduino projects. It is simple to use, requires only 4 wires, and can display text clearly for various electronics projects such as temperature monitors, counters, sensors, and automation systems.

Easy LCD Display Module for Arduino Projects.

In this tutorial, we will learn how to connect and use the LCD 1602 I2C display with Arduino UNO.

What is LCD 1602 I2C?

The LCD 1602 I2C is a 16x2 character display module with an I2C interface adapter attached at the back. Compared to a normal LCD 1602, the I2C version uses fewer Arduino pins, making wiring much easier and cleaner.

The display can show:

• 16 characters per row
• 2 rows of text
• Letters, numbers, and symbols

It is suitable for beginners and advanced Arduino users.

LCD 1602 I2C Specifications

LCD 1602 I2C Technical Specifications.

Here are the basic specifications of the LCD module:

• Display Type: Character LCD
• Display Format: 16x2
• Interface: I2C Communication
• Operating Voltage: 5V DC
• Adjustable Contrast
• Only 4 Wires Required

The module usually comes in Blue or Yellow-Green backlight versions.

Components Required

Components Needed for This Project.

For this project, we need:

• Arduino UNO R3
• LCD 1602 I2C Module
• Jumper Wires
• Breadboard
• USB Cable

Wiring Diagram

LCD 1602 I2C Wiring Connection.

Connect the LCD 1602 I2C to Arduino UNO using the following connections:

LCD I2C → Arduino UNO
VCC → 5V
GND → GND
SDA → A4
SCL → A5

The I2C interface allows communication using only SDA and SCL pins.

Actual Wiring Connection

Actual Hardware Wiring Setup.

After checking the wiring diagram, connect all components using jumper wires.

Make sure:

• Wires are connected securely
• VCC and GND are not reversed
• SDA and SCL are connected correctly

Incorrect wiring may cause the LCD not to display any text.

Check LCD Address Using I2C Scanner

Check LCD I2C Address First.

Before uploading the LCD code, it is important to check the I2C address of the module.

Most LCD 1602 I2C modules use:

• 0x27
• 0x3F

Upload the I2C Scanner code to Arduino and open the Serial Monitor to detect the correct address.

If the address is different, change it inside the LCD code.

LCD 1602 I2C Arduino Code

Upload LCD Arduino Code.

After confirming the I2C address, upload the LCD display code using Arduino IDE. You can download HERE.

This example will display scrolling text:
“Welcome To MCE :)”

The code uses:

• Wire.h library
• LiquidCrystal_I2C library

The text will continuously move across the LCD display.

Adjust LCD Contrast

Adjust LCD Contrast Potentiometer.

If the display is blank or difficult to see, adjust the blue potentiometer at the back of the LCD module.

Rotate:

• Clockwise
• Counter clockwise

until the characters become visible clearly.

Final Result

Final LCD Display Output.

Once everything is connected correctly and the code is uploaded successfully, the LCD will display:

Welcome To MCE :)

You should now see the scrolling text running smoothly on the LCD display.

📦 Where to Buy

Shopee:

1. UNO R3
2. LCD Display
3. Dupont Jumper

Lazada:

1. UNO R3
2. LCD Display
3. Dupont Jumper

TikTok:

1. UNO R3
2. LCD Display
3. Dupont Jumper

Aliexpress:

1. UNO R3
2. LCD Display
3. Dupont Jumper

Conclusion

Using LCD 1602 I2C with Arduino UNO is simple and beginner-friendly. Since it only requires 4 wires, it helps reduce complicated wiring and saves Arduino pins for other sensors and modules. We hope this tutorial helps you start using LCD 1602 I2C in your own Arduino projects.

How to Use 0–25V Voltage Sensor Module with Arduino UNO

In this tutorial, we will learn how to use the 0–25V DC Voltage Sensor Module with Arduino UNO. This sensor module allows Arduino to measure higher DC voltages safely through the analog input pin. It is commonly used for battery monitoring, solar projects, power supply measurement, and other DIY electronics applications.

Learning how to measure DC voltage using the 0–25V Voltage Sensor Module with Arduino UNO.

What is a Voltage Sensor Module?

The 0–25V Voltage Sensor Module is a simple voltage divider circuit that reduces higher DC voltages into a safe analog voltage readable by Arduino.

Since Arduino UNO analog pins can only read up to 5V, this module scales down the input voltage before sending it to the microcontroller.

For example:

• 25V input becomes approximately 5V output to Arduino analog pin.

Sensor Specifications

Technical specifications of the 0–25V DC Voltage Sensor Module.

Components Required

Components used in this Arduino voltage monitoring tutorial.

For this project, we need:

• VS-25 Voltage Sensor Module
• Arduino UNO
• Breadboard
• Jumper Wires
• Adjustable DC Power Supply
• USB Cable
• Multimeter

Wiring Connection

Wiring connection between the Voltage Sensor Module and Arduino UNO.

• Connect the S pin to A0
• Connect the negative pin to GND
• Connect the positive pin to the 5V pin on the Arduino UNO
• Connect the adjustable power supply to the voltage input terminal of the sensor module

Arduino Code

Click HERE to download code. Upload the following code to Arduino UNO:

int sensorPin = A0;
float voltage = 0;

void setup() {
  Serial.begin(9600);
}

void loop() {

  int value = analogRead(sensorPin);

  // Formula calculate actual voltage
  voltage = value * (25.0 / 1023.0);

  Serial.print("Voltage: ");
  Serial.println(voltage);

  delay(1000);

}

Testing the Voltage Sensor

Testing the voltage sensor module using adjustable power supply and multimeter.

After uploading the code:

1. Open the Arduino Serial Monitor.
2. Turn on the adjustable power supply.
3. Adjust the voltage to approximately 19.83V.
4. Observe the reading on the Serial Monitor.

During testing, the Arduino reading may show a slightly different value compared to the multimeter reading.

Serial Monitor and multimeter voltage comparison during testing.

This small difference is normal because the voltage sensor module is not a high-precision measurement device. However, the result is still close enough and suitable for most hobby and DIY electronics projects.

Applications

This voltage sensor module can be used for:

• Battery Voltage Monitoring
• Solar Power Projects
• DC Power Supply Monitoring
• Automotive Voltage Detection
• DIY Electronics Projects
• IoT Voltage Monitoring Systems

📦 Where to Buy

Shopee:

1. UNO R3
2. Voltage Sensor
3. Dupont Jumper
4. Adjustable Power Supply

Lazada:

1. UNO R3
2. Voltage Sensor
3. Dupont Jumper
4. Adjustable Power Supply

TikTok:

1. UNO R3
2. Voltage Sensor
3. Dupont Jumper
4. Adjustable Power Supply

Aliexpress:

1. UNO R3
2. Voltage Sensor
3. Dupont Jumper
4. Adjustable Power Supply

Conclusion

The 0–25V Voltage Sensor Module is a simple and affordable way to measure DC voltage using Arduino UNO. It is beginner-friendly, easy to connect, and useful for many electronics projects. Although it is not highly accurate like professional measuring equipment, it performs well enough for learning and DIY applications. 

Thank you for reading this tutorial. Don’t forget to like, share, and subscribe for more Arduino and electronics projects.