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.

How to Build a STEM Reptile Robot – Fun DIY Robotics Project for Beginners

STEM education is becoming more popular among kids, students, and hobby makers because it combines Science, Technology, Engineering, and Mathematics into exciting hands-on learning activities. One fun project that introduces basic robotics and mechanical engineering is the STEM Reptile Robot.

STEM Reptile Robot DIY Assembly Tutorial.

Step 1 – Prepare All Parts

Prepare All Components Before Assembly.

Start by opening the science invention kit and arranging all components neatly on the table. Check that every part is included before assembly begins.

Step 2 – Install the Motor

Installing the DC Motor.

Attach plates number 1 and 2 onto the motor using screws. Make sure the motor is secured tightly because it powers the entire robot.

Step 3 – Connect the Battery Wires

Connecting Battery Wires to the Motor.

Pass the battery box wires through board number 3 and connect them to the motor terminals carefully. Ensure the positive and negative terminals are connected correctly.

Step 4 – Secure the Motor Assembly

Securing the Motor Structure.

Install the motor assembly onto plate number 5 using screws to form the main body structure.

Step 5 – Install the Gear Mechanism

Installing Gears and Shaft Mechanism.

Insert the gear and shaft through plate number 4, then install another plate and secure it using the orange bushing. Proper alignment is important for smooth movement.

Step 6 – Attach the Battery Box

Installing the Battery Holder.

Secure board number 3 onto board number 4 using screws. Then install the battery box onto board number 3.

Step 7 – Install the Pulley and Shaft

Pulley and Iron Shaft Installation.

Attach the pulley onto the gear shaft and secure the iron shaft using bushings. The shaft alignment affects the robot’s walking performance.

Step 8 – Install the Walking Legs

Assembling the Walking Legs

Install orange bushing.

Connect the linkage arms and legs carefully. Leave approximately a 1mm gap between the orange bushing and plate number 5 to reduce resistance and improve movement.

Repeat the same steps for the opposite side of the robot.

Step 9 – Final Decoration

Adding Decorative Robot Eyes.

Peel the tape from the decorative eyes and attach them onto the battery compartment to give the robot a fun appearance.

Testing the Robot

STEM Reptile Robot Walking Test.

After inserting the batteries, switch the robot on and observe the walking movement. The rotating gear system converts motor rotation into a stepping motion through the linkage mechanism.

Educational Benefits of STEM Robot Kits

Building a STEM Reptile Robot helps develop:

• Problem-solving skills
• Creativity
• Basic engineering knowledge
• Mechanical understanding
• Hand-eye coordination
• Interest in robotics and technology

📦 Where to Buy

Shopee:

1. STEM Reptile Robot

Lazada:

1. STEM Reptile Robot

TikTok:

1. STEM Reptile Robot

Aliexpress:

1. STEM Reptile Robot

Final Thoughts

The STEM Reptile Robot is an excellent beginner-friendly robotics project for kids, students, and DIY enthusiasts. It combines learning and entertainment while introducing important STEM concepts in an easy and engaging way.

Whether for school projects, home learning, or hobby building, this walking robot kit is a great way to start exploring robotics and engineering.

SR04M-2 Ultrasonic Sensor with Arduino (Complete Beginner Tutorial)

Measuring distance using Arduino is one of the most useful beginner projects. In this tutorial, you’ll learn how to use the SR04M-2 ultrasonic sensor to measure distance accurately for real-world applications. The SR04M-2 is a waterproof ultrasonic sensor that measures distance by sending sound waves and receiving the echo.

A step-by-step guide to measure distance using a waterproof ultrasonic sensor and Arduino.

⚙️ Key Features

• Waterproof probe
• Range: 20cm to 400cm
• Operating voltage: 5V
• Stable and accurate readings

🔌 Wiring Diagram & Connections

How to connect the sensor to Arduino.

5V → 5V

GND → GND

RX → Pin 3

TX → Pin 2

💻 Arduino Code

Program to read and display distance.

Install the NewPing library before uploading the code. Click HERE to download code.

📥 Library Installation

1. Open Arduino IDE
2. Go to Sketch → Include Library → Manage Libraries
3. Search “NewPing”
4. Click Install

📜 Code

#include <newping.h>

#define TRIGGER_PIN  3 
#define ECHO_PIN     2  
#define MAX_DISTANCE 400 
NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); 

float tempval1;
float tempval2 = 60;
int finalval;
unsigned long lastPingTime = 0;
unsigned long pingInterval = 50;

void setup() {
  Serial.begin(57600);
}

void loop() {
  unsigned long currentTime = millis();
  
  if ((currentTime - lastPingTime >= pingInterval)) {
    
    unsigned int distance = sonar.ping_cm();
    
    if (distance > 0) {
      tempval1 = distance;
      
      float diff = abs(tempval1 - tempval2);
      
      if (diff > 2) {
        
        if (diff > 30) {
          tempval2 = (tempval1 * 0.7) + (tempval2 * 0.3);
        } else {
          tempval2 = (tempval1 * 0.4) + (tempval2 * 0.6);
        }
        
        finalval = tempval2;
        
        Serial.print("Ping: ");
        Serial.print(finalval);
        Serial.println("cm");
      }
    }
    
    lastPingTime = currentTime;
  }
}

🧪 Testing the Sensor

Checking real-time distance readings.

1. Open Serial Monitor
2. Set baud rate to 57600
3. Move an object closer and farther

⚙️ How It Works

The sensor sends ultrasonic waves and calculates distance based on the time taken for the echo to return. The code also smooths readings to reduce noise.

🚀 Applications

• Water level monitoring
• Parking systems
• Obstacle detection robots
• Smart irrigation

📦 Where to Buy

Shopee:

1. UNO R3
2. SR04M-2 Sensor
3. Dupont Jumper

Lazada:

1. UNO R3
2. SR04M-2 Sensor
3. Dupont Jumper

TikTok:

1. UNO R3
2. SR04M-2 Sensor
3. Dupont Jumper

Aliexpress:

1. UNO R3
2. SR04M-2 Sensor
3. Dupont Jumper

✅ Conclusion

You’ve learned how to connect, code, and test the SR04M-2 ultrasonic sensor with Arduino. This is a great starting point for many automation projects. If this helped you, please like 👍 and share 🔄 this tutorial.