import network
import time
from machine import Pin, time_pulse_us
import ubinascii
from umqtt.simple import MQTTClient

# WiFi credentials
SSID = 'Wokwi-GUEST'
PASSWORD = ''

# MQTT credentials
MQTT_BROKER = "broker.mqttdashboard.com"
MQTT_CLIENT_ID = "dausfirdaus"
MQTT_TOPIC = "distance_sensor"

# Ultrasonic sensor pins
TRIG_PIN = 4
ECHO_PIN = 5

# Connect to WiFi
def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(SSID, PASSWORD)
    while not wlan.isconnected():
        print('Connecting to WiFi...')
        time.sleep(1)
    print('Connected to WiFi:', wlan.ifconfig())

# Connect to MQTT broker
def connect_mqtt():
    client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER)
    client.connect()
    print('Connected to MQTT Broker')
    return client

# Measure distance using ultrasonic sensor
def measure_distance():
    trig = Pin(TRIG_PIN, Pin.OUT)
    echo = Pin(ECHO_PIN, Pin.IN)
    
    # Ensure trigger is low
    trig.value(0)
    time.sleep_us(2)
    
    # Trigger the sensor
    trig.value(1)
    time.sleep_us(10)
    trig.value(0)
    
    # Measure the pulse width on the echo pin
    pulse_time = time_pulse_us(echo, 1, 1000000)
    distance = (pulse_time / 2) / 29.1  # Convert time to distance
    
    return distance

# MQTT message callback
def on_message(topic, msg):
    print('Received message:', msg)
    # Add your code to handle received messages

# Main function
def main():
    connect_wifi()
    client = connect_mqtt()
    client.set_callback(on_message)
    client.subscribe(MQTT_TOPIC)
    
    try:
        while True:
            client.check_msg()  # Check for new messages
            distance = measure_distance()
            print('Distance:', distance, 'cm')
            # Add your code to publish or process the distance
            time.sleep(1)
    except KeyboardInterrupt:
        print('Disconnected')
        client.disconnect()

if __name__ == '__main__':
    main()