import machine
import utime

# Pins definieren
trig_pin = machine.Pin(28, machine.Pin.OUT)
echo_pin = machine.Pin(27, machine.Pin.IN)
red_led = machine.Pin(15, machine.Pin.OUT)
yellow_led = machine.Pin(13, machine.Pin.OUT)
green_led = machine.Pin(6, machine.Pin.OUT)
buzzer = machine.Pin(26, machine.Pin.OUT)

def measure_distance():
    trig_pin.low()
    utime.sleep_us(2)
    trig_pin.high()
    utime.sleep_us(10)
    trig_pin.low()
    
    while echo_pin.value() == 0:
        signal_off = utime.ticks_us()
    while echo_pin.value() == 1:
        signal_on = utime.ticks_us()
    
    time_passed = utime.ticks_diff(signal_on, signal_off)
    distance = (time_passed * 0.0343) / 2  # Schallgeschwindigkeit: 343 m/s, umgerechnet auf cm/us und geteilt durch 2 (hin und zurück)
    
    return distance

def alert(distance):
    if distance < 50:
        red_led.on()
        yellow_led.off()
        green_led.off()
        buzzer.on()
    elif distance < 100:
        red_led.off()
        yellow_led.on()
        green_led.off()
        buzzer.on()
        utime.sleep(0.1)
        buzzer.off()
        utime.sleep(0.1)
    elif distance < 150:
        red_led.off()
        yellow_led.off()
        green_led.on()
        buzzer.off()
    else:
        red_led.off()
        yellow_led.off()
        green_led.off()
        buzzer.off()

try:
    while True:
        distance = measure_distance()
        print("Distance:", distance, "cm")
        alert(distance)
        utime.sleep(0.1)
except KeyboardInterrupt:
    red_led.off()
    yellow_led.off()
    green_led.off()
    buzzer.off()
    print("Programm beendet")