from machine import Pin
from time import sleep, ticks_us, ticks_diff

# Pin configuration
trigger = Pin(15, Pin.OUT)
echo = Pin(14, Pin.IN)

green_led1 = Pin(16, Pin.OUT)
green_led2 = Pin(17, Pin.OUT)
yellow_led1 = Pin(18, Pin.OUT)
yellow_led2 = Pin(19, Pin.OUT)
red_led1 = Pin(20, Pin.OUT)
red_led2 = Pin(21, Pin.OUT)
red_led3 = Pin(22, Pin.OUT)

def measure_distance():
    trigger.low()
    sleep(0.000002)  # 2 microseconds
    trigger.high()
    sleep(0.00001)   # 10 microseconds
    trigger.low()

    while echo.value() == 0:
        signal_off = ticks_us()
    while echo.value() == 1:
        signal_on = ticks_us()

    time_passed = ticks_diff(signal_on, signal_off)
    distance = (time_passed * 0.0343) / 2  # Convert to cm
    return distance

# Function to control LEDs based on distance
def indicate_distance(distance):
    # Turn off all LEDs first
    red_led1.off()
    red_led2.off()
    red_led3.off()
    yellow_led1.off()
    yellow_led2.off()
    green_led1.off()
    green_led2.off()

    # Control LEDs based on distance
    if distance < 3:  
        red_led3.on()
        red_led2.on()
        red_led1.on()
    elif distance < 7: 
        red_led2.on()
        red_led1.on()
    elif distance < 13: 
        red_led1.on()
    elif distance < 20:  
        yellow_led2.on()
        yellow_led1.on()
    elif distance < 25:
        yellow_led1.on()
    elif 25 < distance <= 27:
         green_led2.on()
         green_led1.on()
    else: 
        green_led1.on()

try:
    while True:
        distance = measure_distance()
        print("Distance:", distance, "cm")
        indicate_distance(distance)
        sleep(1)  
finally:
   
    red_led1.off()
    red_led2.off()
    red_led3.off()
    yellow_led1.off()
    yellow_led2.off()
    green_led1.off()
    green_led2.off()