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

const int pingPin = 7; // Pin connected to the SIG pin of the sensor

const int numReadings = 10; // Number of readings for the moving average filter

long readings[numReadings]; // Array to store the sensor readings

int readIndex = 0; // Index of the current reading

long total = 0; // Sum of the readings

long average = 0; // Average of the readings

void setup() {

Serial.begin(9600); // Initialize serial communication

for (int i = 0; i < numReadings; i++) {

readings[i] = 0; // Initialize all readings to 0

}

}

void loop() {

// Establish variables for duration of the ping, and the distance result in inches and centimeters:

long duration, distance;

// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.

// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:

pinMode(pingPin, OUTPUT);

digitalWrite(pingPin, LOW);

delayMicroseconds(2);

digitalWrite(pingPin, HIGH);

delayMicroseconds(5);

digitalWrite(pingPin, LOW);

// The same pin is used to read the signal from the PING))): a HIGH pulse whose duration is the time (in microseconds) from the sending of the ping to the reception of its echo off an object.

pinMode(pingPin, INPUT);

duration = pulseIn(pingPin, HIGH);

// Convert the time into a distance

distance = duration / 29 / 2; // Distance in cm

// Update the moving average

total = total - readings[readIndex]; // Subtract the last reading

readings[readIndex] = distance; // Store the new reading

total = total + readings[readIndex]; // Add the new reading to the total

readIndex = (readIndex + 1) % numReadings; // Advance to the next position in the array

average = total / numReadings; // Calculate the average

// Print the average distance

Serial.print("Distance (cm): ");

Serial.println(average);

delay(100); // Wait a bit before the next loop

}