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

import RPi.GPIO as GPIO

import time

class UltrasonicSensor:

def __init__(self, trig_pin, echo_pin):

self.trig_pin = trig_pin

self.echo_pin = echo_pin

GPIO.setup(trig_pin, GPIO.OUT)

GPIO.setup(echo_pin, GPIO.IN)

def get_distance(self):

# Trigger pulse

GPIO.output(self.trig_pin, True)

time.sleep(0.00001)

GPIO.output(self.trig_pin, False)

# Wait for echo start

while GPIO.input(self.echo_pin) == 0:

pulse_start = time.time()

# Wait for echo end

while GPIO.input(self.echo_pin) == 1:

pulse_end = time.time()

# Calculate pulse duration

pulse_duration = pulse_end - pulse_start

# Speed of sound is approximately 343m/s

# Distance = time * speed

distance = pulse_duration * 34300 / 2

return distance

class MovingAverageFilter:

def __init__(self, window_size):

self.window_size = window_size

self.data = []

def add_data(self, value):

if len(self.data) < self.window_size:

self.data.append(value)

else:

self.data.pop(0)

self.data.append(value)

def get_filtered_value(self):

return sum(self.data) / len(self.data)

# GPIO Pins (example pins, adjust as per your connections)

TRIG_PIN = 23

ECHO_PIN = 24

# Initialize GPIO

GPIO.setmode(GPIO.BCM)

GPIO.setwarnings(False)

# Initialize Ultrasonic Sensor and Moving Average Filter

ultrasonic_sensor = UltrasonicSensor(TRIG_PIN, ECHO_PIN)

moving_average_filter = MovingAverageFilter(window_size=5)

try:

while True:

# Measure distance

distance = ultrasonic_sensor.get_distance()

# Add distance data to the moving average filter

moving_average_filter.add_data(distance)

# Get filtered distance

filtered_distance = moving_average_filter.get_filtered_value()

print("Distance: {:.2f} cm | Filtered Distance: {:.2f} cm".format(distance, filtered_distance))

time.sleep(1)

except KeyboardInterrupt:

GPIO.cleanup()