Ultrasonic Sensor

1. Wire the Ultrasonic Sensor according to the diagram.

• Connect VCC to VIN (5V).

• Connect GND to GND.

• Connect Trig to D5 (GPIO 5).

• Connect Echo to D18 (GPIO 18).

2. Copy and paste the source code.

• Copy the ultrasonic sensor code and paste it into the editor.

• Click the Run button (or press F5) to start the program.

from machine import Pin, time_pulse_us

import time

# 1. Setup Pins

trig = Pin(5, Pin.OUT)

echo = Pin(18, Pin.IN)

def get_distance():

    # Ensure Trig is low

    trig.value(0)

    time.sleep_us(5)

    # Send a 10us pulse to trigger the sensor

    trig.value(1)

    time.sleep_us(10)

    trig.value(0)

    # Measure the duration of the echo pulse in microseconds

    # 30000us is the timeout (approx 5 meters)

    duration = time_pulse_us(echo, 1, 30000)

    if duration < 0:

        return 0 # Out of range

    # Calculate distance in cm (Speed of sound is ~340m/s or 0.034 cm/us)

    distance = (duration * 0.034) / 2

    return round(distance, 2)

print("Ultrasonic Sensor Ready!")

print("Open Thonny Plotter (View -> Plotter) to see the graph.")

while True:

    dist = get_distance()

    print((dist,)) # Tuple format for Thonny Plotter

    time.sleep(0.1)

3. Verify the data and open the Plotter.

• Check the Shell window to ensure distance data (numbers) is appearing.

• Go to the top menu: View -> Plotter.

• A real-time graph will appear on the right side of the screen.