import time
from machine import Pin
# Ultrasonic pins
trigger = Pin(3, Pin.OUT)
echo = Pin(2, Pin.IN)
# LED pin
led = Pin(14, Pin.OUT)
def get_distance():
# Send trigger pulse
trigger.low()
time.sleep_us(2)
trigger.high()
time.sleep_us(10)
trigger.low()
# Measure echo time
while echo.value() == 0:
signal_off = time.ticks_us()
while echo.value() == 1:
signal_on = time.ticks_us()
# Time difference
time_passed = time.ticks_diff(signal_on, signal_off)
# Convert to distance (cm)
distance = (time_passed * 0.0343) / 2
return distance
print("Ultrasonic Distance Detection Ready...")
while True:
distance = get_distance()
print("Distance:", distance, "cm")
# 5 meters = 500 cm
if distance <= 50:
led.value(1) # Object detected → LED ON
else:
led.value(0) # No object → LED OFF
time.sleep(0.2)