How to Use an LDR Sensor With Arduino

This project reads the value from a Light Dependent Resistor (LDR) and displays it on a 16x2 LCD screen using an I2C module. The LCD will show the LDR value in the first row and the text "COSMELECTRONICS" in the second row.

Components Required

• Arduino board (e.g., Uno, Mega, Nano)
• LDR (Light Dependent Resistor)
• 10k ohm resistor
• 16x2 LCD display with I2C module
• Breadboard and connecting wires

Circuit Diagram

1. LDR and Resistor:

   • Connect one end of the LDR to 5V.
   • Connect the other end of the LDR to the analog input pin A0.
   • Connect one end of the 10k ohm resistor to GND.
   • Connect the other end of the 10k ohm resistor to the junction between the LDR and the analog input pin A0.

2. 16x2 LCD with I2C:

   • Connect the VCC and GND of the I2C module to 5V and GND on the Arduino, respectively.
   • Connect the SDA pin of the I2C module to the SDA pin on the Arduino (A4 on Uno/Nano, 20 on Mega).
   • Connect the SCL pin of the I2C module to the SCL pin on the Arduino (A5 on Uno/Nano, 21 on Mega).

Libraries Required

• Wire.h: For I2C communication.
• LiquidCrystal_I2C.h: For controlling the LCD display via I2C.

Setup Instructions

1. Install the Required Libraries:

   • Open the Arduino IDE.
   • Go to Sketch > Include Library > Manage Libraries....
   • Search for LiquidCrystal I2C and install the library by Frank de Brabander.

2. Upload the Code:

   • Open the Arduino IDE and copy the code from LDR_LCD_I2C.ino.
   • Connect your Arduino board to your computer.
   • Select the correct board and port from the Tools menu.
   • Click the Upload button.

How It Works

• The code reads the analog value from the LDR connected to pin A0.
• This value is then printed to the serial monitor for debugging purposes.
• The same value is displayed on the first row of the 16x2 LCD.
• The second row of the LCD displays the text "COSMELECTRONICS".

Acknowledgements

• This code is designed by Prince Kushwaha.