Project 2 - Measuring the distance of an object using ultrasonic sensor and also smoothen the sensor data using moving average filter

Components are used

1. Arduino Uno
2. LCD 
3. 250 k ohm Potentiometer
4. 220 ohm Resistor
5. Ultrasonic Distance Sensor

Circuit Diagram :-

Output fig :-

Program :-

#include

const int numReadings = 10;  // Number of readings to average
int readings[numReadings];  // Array to store sensor readings
int index = 0;  // Index for the current reading
int total = 0;  // Total sum of readings

int inches = 0;  // Distance in inches
int cm = 0;  // Distance in centimeters

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);  // LCD display object

void setup() {
  lcd.begin(16, 2);  // Initialize LCD display with 16 columns and 2 rows
  lcd.print("New String !!!");  // Display a string on the LCD
  Serial.begin(9600);  // Initialize serial communication at 9600 baud rate
  pinMode(7, INPUT);  // Set pin 7 as input
}

void loop() {
  lcd.clear();  // Clear the LCD display

  cm = 0.01723 * readUltrasonicDistance(7);  // Read distance from the ultrasonic sensor in centimeters
  
  // Update the array with the latest reading
  total = total - readings[index];  // Subtract the oldest reading from the total sum
  readings[index] = cm;  // Store the new reading in the array
  total = total + readings[index];  // Add the new reading to the total sum
  index = (index + 1) % numReadings;  // Move to the next index or wrap around to 0 if the end is reached
  
  // Calculate the average distance
  cm = total / numReadings;  // Calculate the average in centimeters
  inches = cm / 2.54;  // Convert centimeters to inches

  Serial.print("cm: ");  // Print label to the serial monitor
  Serial.print(cm);  // Print the distance in centimeters

  lcd.setCursor(0, 0);  // Set the LCD cursor to the first column of the first row
  lcd.print("cm: ");  // Display label on the LCD
  lcd.setCursor(4, 0);  // Set the LCD cursor to the fifth column of the first row
  lcd.print(cm);  // Display the distance in centimeters on the LCD

  Serial.print("inch: ");  // Print label to the serial monitor
  Serial.println(inches);  // Print the distance in inches

  lcd.setCursor(0, 1);  // Set the LCD cursor to the first column of the second row
  lcd.print("inch: ");  // Display label on the LCD
  lcd.setCursor(6, 1);  // Set the LCD cursor to the seventh column of the second row
  lcd.print(inches);  // Display the distance in inches on the LCD

  delay(250);  // Delay 
}

long readUltrasonicDistance(int pin) {
  pinMode(pin, OUTPUT);  // Set the pin as output
  digitalWrite(pin, LOW);  // Set the pin to low
  delayMicroseconds(2);  // Delay for 2 microseconds
  digitalWrite(pin, HIGH);  // Set the pin to high
  delayMicroseconds(10);  // Delay for 10 microseconds
  digitalWrite(pin, LOW);  // Set the pin to low
  pinMode(pin, INPUT);  // Set the pin as input
  return pulseIn(pin, HIGH);  // Measure the pulse duration and return the result
}