from machine import Pin, PWM
import time

TRIGGER_PIN = 12  # 超音波感應器的觸發引腳
ECHO_PIN = 14     # 超音波感應器的回音引腳
BUZZER_PIN = 2    # 蜂鳴器的引腳

trigger = Pin(TRIGGER_PIN, Pin.OUT)
echo = Pin(ECHO_PIN, Pin.IN)
buzzer = PWM(Pin(BUZZER_PIN))

def get_distance():
    # 使用超音波感應器測量距離（單位：厘米）
    trigger.value(1)
    time.sleep_us(10)
    trigger.value(0)
    pulse_time = machine.time_pulse_us(echo, 1)
    return pulse_time / 58  # 將脈衝時間轉換為距離

def play_short_tone():
    # 發出0.5秒的短音
    buzzer.freq(1000)
    buzzer.duty(50)
    time.sleep(0.5)
    buzzer.duty(0)

def play_continuous_tone():
    # 發出連續長音
    buzzer.freq(1000)
    buzzer.duty(50)

def stop_tone():
    # 停止發聲
    buzzer.duty(0)

while True:
    distance = get_distance()
    print("Distance: {} cm".format(distance))

    if distance < 100:
        # 如果距離小於100厘米，發出0.5秒的短音
        play_short_tone()
        time.sleep(0.5)

    if distance < 30:
        # 如果距離小於30厘米，發出連續長音
        play_continuous_tone()
    else:
        stop_tone()