Circuit Documentation

Summary

This circuit is designed using an Arduino UNO microcontroller to control a 20x4 LCD display. The circuit includes a trimmer potentiometer for adjusting the display contrast and a resistor for current limiting. The LCD is connected to the Arduino using a 4-bit data interface, allowing for efficient communication and control of the display.

Component List

Arduino UNO

• Description: A microcontroller board based on the ATmega328P. It is used to control the circuit and interface with the LCD.
• Purpose: Acts as the main controller for the circuit, executing the code to manage the LCD display.

Trimmer Potentiometer

• Description: A variable resistor used to adjust the voltage level.
• Purpose: Used to control the contrast of the LCD display.

Resistor

• Description: A passive electrical component that limits the flow of current in a circuit.
• Purpose: Provides a current-limiting function for the LCD display.

LCD 20x4

• Description: A 20x4 character LCD display that can show 20 characters per line and has 4 lines.
• Purpose: Displays information and messages to the user.

Wiring Details

Arduino UNO

• 5V: Connected to the Trimmer Potentiometer (leg1) and LCD (Vdd).

• GND: Connected to the Trimmer Potentiometer (leg2), LCD (Vss, K-), and LCD (R/W).

• D12: Connected to the LCD (RS).

• D11: Connected to the LCD (E).

• D7: Connected to the LCD (DB4).

• D6: Connected to the LCD (DB5).

• D5: Connected to the LCD (DB6).

• D4: Connected to the LCD (DB7).

Trimmer Potentiometer

• leg1: Connected to the Arduino UNO (5V).

• leg2: Connected to the Arduino UNO (GND).

• wiper: Connected to the LCD (Vo).

Resistor

• pin1: Connected to the Arduino UNO (5V).

• pin2: Connected to the LCD (A+).

LCD 20x4

• Vss: Connected to the Arduino UNO (GND).

• Vdd: Connected to the Arduino UNO (5V).

• Vo: Connected to the Trimmer Potentiometer (wiper).

• RS: Connected to the Arduino UNO (D12).

• R/W: Connected to the Arduino UNO (GND).

• E: Connected to the Arduino UNO (D11).

• DB0: Not connected.

• DB1: Not connected.

• DB2: Not connected.

• DB3: Not connected.

• DB4: Connected to the Arduino UNO (D7).

• DB5: Connected to the Arduino UNO (D6).

• DB6: Connected to the Arduino UNO (D5).

• DB7: Connected to the Arduino UNO (D4).

• A+: Connected to the Resistor (pin2).

• K-: Connected to the Arduino UNO (GND).

Documented Code

#include <LiquidCrystal.h>

// Wiring per your circuit:
// RS -> D12, E -> D11, DB4->D7, DB5->D6, DB6->D5, DB7->D4
LiquidCrystal lcd(12, 11, 7, 6, 5, 4);

void setup() {
  lcd.begin(20, 4); // 20 columns, 4 rows
  lcd.clear();

  lcd.setCursor(0, 0);
  lcd.print("Welcome to");
  lcd.setCursor(0, 1);
  lcd.print("Cirkit Designer");

  lcd.setCursor(0, 2);
  lcd.print("LCD built by");
  lcd.setCursor(0, 3);
  lcd.print("Surya Kalyan");
}

void loop() {
  // Nothing else needed
}

This documentation provides a comprehensive overview of the circuit, detailing each component, its purpose, and the wiring connections. The included code initializes the LCD and displays a welcome message.