from machine import Pin
import time
from hcsr04 import HCSR04
import network
from umqtt.simple import MQTTClient

# Wi-Fi设置
ssid = 'Wokwi-GUEST'
password = ''

# 巴法云MQTT服务器设置
mqtt_server = 'bemfa.com'
mqtt_port = 9501
mqtt_user = 'd353077c44054dedb9bc28d55b361fd7'
mqtt_topic = 'distance'

# 初始化HC-SR04传感器
hcsr04 = HCSR04(trigger_pin=4, echo_pin=27)



# 连接Wi-Fi
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
wlan.connect(ssid, password)

while not wlan.isconnected():
    time.sleep(1)
    print('.', end='')  # 打印点以显示连接进度

print('\nConnected to WiFi')

# MQTT客户端
client = MQTTClient(client_id=mqtt_user, server=mqtt_server, user=mqtt_user, password='', port=mqtt_port)

# 尝试连接到MQTT服务器，如果失败则打印错误信息
try:
    client.connect()
    print('Connected to MQTT server')
except Exception as e:
    print('Failed to connect to MQTT server:', e)
    time.sleep(10)  # 等待10秒后重启，避免无限循环
    raise  # 重新抛出异常，以便在Wokwi中重启模拟

def send_distance():
    while True:
        try:
            # 获取以厘米为单位的距离
            distance = hcsr04.distance_cm()
            if distance < 0:  # 忽略负数距离值
                print('Invalid distance reading')
                distance = 0
            else:
                print('Distance: {:.2f} cm'.format(distance))
            client.publish(mqtt_topic, '{:.2f}'.format(distance))
            
        except Exception as e:
            print('Error sending distance:', e)
        time.sleep(1)

send_distance()