Project Documentation

Ultrasonic Distance Measurement with Servo Control and LCD Display

Circuit Documentation

Summary

This circuit integrates an Arduino Uno R3 microcontroller with various components including ultrasonic sensors, a servo motor, an LCD display, a relay, and a fan. The primary function of the circuit is to measure distance using the HC-SR04 ultrasonic sensor, display the measured distance on the LCD, and control the position of a servo motor based on the distance measured. Additionally, the circuit includes a relay to control a 220V fan based on certain conditions.

Component List

Arduino Uno R3

Description: A microcontroller board based on the ATmega328P.
Purpose: Acts as the central control unit for the circuit, processing inputs from the ultrasonic sensor and controlling the servo motor and LCD display.

Servo

Description: A small motor that can be controlled to rotate to a specific angle.
Purpose: Adjusts its position based on the distance measured by the ultrasonic sensor.

HC-SR04 Ultrasonic Sensor

Description: A distance measuring sensor that uses ultrasonic waves.
Purpose: Measures the distance to an object and provides this data to the Arduino.

220 Fan

Description: An electric fan powered by 220V AC.
Purpose: Provides cooling; controlled via a relay.

Lcd 20x4 I2C

Description: A 20x4 character LCD display with I2C interface.
Purpose: Displays the distance measured by the ultrasonic sensor.

Power Transformer (220V to 24V)

Description: A transformer that converts 220V AC to 24V AC.
Purpose: Supplies power to the relay and fan.

12V Relay

Description: An electromechanical switch that can control high voltage devices.
Purpose: Controls the operation of the 220V fan based on signals from the Arduino.

Fuse

Description: A safety device that protects the circuit from overcurrent.
Purpose: Prevents damage to components by breaking the circuit in case of excessive current.

Power 220V

Description: The main power supply for the circuit.
Purpose: Provides the necessary voltage for the fan and relay operation.

Wiring Details

Arduino Uno R3

5V connected to Servo VCC
GND connected to Servo GND
GND connected to HC-SR04 GND
A3 connected to HC-SR04 TRIG
A4/SDA connected to LCD SCA
A5/SCL connected to LCD SCL
12 connected to HC-SR04 ECHO
6 connected to Servo PULSE
GND connected to LCD GND

Servo

VCC connected to Arduino 5V
GND connected to Arduino GND
PULSE connected to Arduino pin 6

HC-SR04 Ultrasonic Sensor

VCC connected to Arduino 5V
GND connected to Arduino GND
TRIG connected to Arduino pin A3
ECHO connected to Arduino pin 12

220 Fan

N connected to Relay COM
L connected to Fuse Terminal 2

Lcd 20x4 I2C

GND connected to Arduino GND
5V connected to Arduino 5V
SCA connected to Arduino A4/SDA
SCL connected to Arduino A5/SCL

Power Transformer (220V to 24V)

2 - Primary connected to Power 220V hot wire
1 - Primary connected to Power 220V neutral wire
3 - Secondary connected to Fuse Terminal 1
4 - Secondary connected to Relay NO

12V Relay

DC+ connected to Arduino 5V
DC- connected to Arduino GND
COM connected to Fan N
NO connected to Fan L

Fuse

Terminal 1 connected to Transformer Secondary 3
Terminal 2 connected to Fan L

Documented Code

Arduino Uno R3 Code

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

HC-SR04 Ultrasonic Sensor Code

/*
 * This Arduino Sketch controls an HC-SR04 Ultrasonic Sensor, a Servo motor,
 * and an LCD display. The sensor measures the distance to an object, the
 * distance is displayed on the LCD, and the Servo motor rotates based on
 * the measured distance.
 */

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Servo.h>

#define TRIG_PIN A3
#define ECHO_PIN 12
#define SERVO_PIN 6

LiquidCrystal_I2C lcd(0x27, 20, 4);
Servo myServo;

void setup() {
  lcd.begin();
  lcd.backlight();
  myServo.attach(SERVO_PIN);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}

void loop() {
  long duration, distance;
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = (duration / 2) / 29.1;
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  lcd.print(distance);
  lcd.print(" cm");
  int angle = map(distance, 0, 100, 0, 180);
  myServo.write(angle);
  delay(500);
}

This documentation provides a comprehensive overview of the circuit, detailing each component, its purpose, wiring connections, and the code used to control the system.