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

PROJECT _ 2

Overview of the Project:

In this project the implementation of code for “Measuring distance of an object using ultrasonic distance sensor (28015 Ping) and also smoothen the sensor data using moving average filter”.

Goals:

• Measuring the distance in terms of inches of an object using Ultrasonic Distance Sensor (28015 Ping).
• The sensor data is smoothened by using Moving average filter technique to eliminate the high frequency variations from the sensor data.

Key Highlights of the Project:

• Measuring the distance travelled by the wave to the object and gets bounced back from the object to sensor.
• Smoothening the sensor data by moving average filter technique, the filter has a window of certain size. That window determines that how many data the filter can take.

Deliverables of this project:

• The distance travelled by a wave to the object for which we want to measure the distance using Ultrasonic Distance Sensor (28015 Ping).
• Eliminate the high frequency jitters from the sensor data by Moving Average filter to smoothen the sensor data.

Expected Outcomes:

The students will get the Knowledge on Ultrasonic sensor (28015 Ping) to measure the distance travelled by wave to the object, the hardware connection of 2 Arduino’s connected to the sensor and smoothening the sensor data by removing high frequency variations using Moving Average Filter Technique.

Solution _

Goal _ 1_a_Measuring the distance in terms of inches of an object using Ultrasonic Distance Sensor (28015 Ping).

Components Needed:

1. Arduino Uno
2. Ultrasonic Distance Sensor(28015 Ping).
3. Potentiometer (simulating an analog sensor)
4. Resistor (for potentiometer)
5. Jumper wires

Connection Setup:

1. Connect the VCC (5V) pin of the Ultrasonic Sensor to the 5V output on the Arduino.
2. Connect the GND pin of the Ultrasonic Sensor to the GND on the Arduino.
3. Connect the Sig pin of the Ultrasonic Sensor to a digital pin (e.g., D2) on the Arduino.
4. This pin is used both for sending the trigger signal and receiving the echo signal.
5. Connect one end of the potentiometer to 5V, the other end to GND, and the wiper to analog pin A0 on the Arduino.
6. Add a resistor between the wiper and the GND to create a voltage divider.

// Arduino Code

const int signalPin = 2; // Connect the SIGNAL pin of the sensor to digital pin 2

void setup() {

Serial.begin(9600); // Initialize serial communication with a baud rate of 9600

}

void loop() {

// Send a pulse to trigger the Ultrasonic Sensor

pinMode(signalPin, OUTPUT); // Set the SIGNAL pin as an OUTPUT

digitalWrite(signalPin, LOW); // Set the SIGNAL pin to LOW for a short duration

delayMicroseconds(2); // Wait for a moment

digitalWrite(signalPin, HIGH); // Set the SIGNAL pin to HIGH to send a pulse

delayMicroseconds(10); // Keep it HIGH for a short duration

digitalWrite(signalPin, LOW); // Set the SIGNAL pin back to LOW

// Measure the time it takes for the echo signal to return

pinMode(signalPin, INPUT); // Set the SIGNAL pin as an INPUT to receive the echo signal

long duration = pulseIn(signalPin, HIGH); // Measure the time the echoPin stays HIGH

// Convert the time to inches using the speed of sound

int inches = microsecondsToInches(duration);

// Print the measured distance to the Serial Monitor

Serial.print("Distance: ");

Serial.print(inches);

Serial.println(" inches");

delay(1000); // Wait for a moment before taking the next measurement

}

long microsecondsToInches(long microseconds) {

// Speed of sound at sea level is approximately 343 meters per second (or 1125 feet per second)

// Dividing by 74 gives the time it takes for the sound to travel round trip (to the target and back)

// Dividing by 2 gives one-way travel time, which is what we need

return microseconds / 74 / 2;

}

Goal _ 1_b_The sensor data is smoothened by using Moving average filter technique to eliminate the high frequency variations from the sensor data.

Moving average filter technique code

const int windowSize = 5; // Define the window size for the moving average filter

int readings[windowSize]; // Array to store sensor readings for the moving average

int index = 0; // Index for the readings array

// Function to calculate the moving average

int movingAverage(int value) {

int total = 0;

// Shift values in the array to make room for the new value

for (int i = windowSize - 1; i > 0; i--) {

readings[i] = readings[i - 1];

total += readings[i];

}

// Add the new sensor value to the array

readings[0] = value;

total += value;

// Calculate and return the moving average

return total / windowSize;

}

void setup() {

Serial.begin(9600); // Begin serial communication at 9600 baud rate

}

void loop() {

int sensorValue = analogRead(A0); // Read the sensor value from analog pin A0

// Smooth the sensor data using the moving average filter

int smoothedValue = movingAverage(sensorValue);

// Print both raw and smoothed sensor values to the Serial Monitor

Serial.print("Raw Sensor Value: ");

Serial.print(sensorValue);

Serial.print("\tSmoothed Value: ");

Serial.println(smoothedValue);

delay(1000); // Wait for a moment before taking the next measurement

}