import time
import urequests  
from machine import Pin, PWM
import network
import BlynkLib

# WiFi credentials
WIFI_SSID = "Your_WiFi_SSID"
WIFI_PASS = "Your_WiFi_Password"

# Blynk authentication token
BLYNK_AUTH_TOKEN = "Your_Blynk_Auth_Token"

# Initialize Wi-Fi connection
wifi = network.WLAN(network.STA_IF)
wifi.active(True)
wifi.connect(WIFI_SSID, WIFI_PASS)

# Wait until connected to WiFi
while not wifi.isconnected():
    pass
print("Connected to WiFi")

# Initialize Blynk
blynk = BlynkLib.Blynk(BLYNK_AUTH_TOKEN)

# Virtual pin handler
@blynk.handle_event('write V1')  # Adjust 'V1' to match the virtual pin you are using
def write_virtual_pin_handler(pin, value):
    print('Virtual Pin {} value: {}'.format(pin, value))

# Ultrasonic sensor pins
trig_pin = Pin(16, Pin.OUT)
echo_pin = Pin(17, Pin.IN)

# Buzzer pins
buzzer_pin = Pin(4, Pin.OUT)
buzzer_pwm = PWM(buzzer_pin)
buzzer_pwm.freq(500)

def measure_distance():
    trig_pin.value(1)
    time.sleep_us(10)
    trig_pin.value(0)

    while echo_pin.value() == 0:
        pulse_start = time.ticks_us()
    while echo_pin.value() == 1:
        pulse_end = time.ticks_us()
    
    pulse_duration = time.ticks_diff(pulse_end, pulse_start)
    distance = pulse_duration * 0.034 / 2

    return distance

def activate_buzzer():
    buzzer_pwm.duty(512)  
    time.sleep(1)
    buzzer_pwm.duty(0)  

def send_to_thingspeak(distance):
    data = {"api_key": THINGSPEAK_API_KEY, "field1": str(distance)}
    response = urequests.post(THINGSPEAK_URL, json=data)
    print("ThingSpeak response:", response.text)
    response.close()

try:
    while True:
        blynk.run() 
        distance = measure_distance()
        print("Distance:", distance, "cm")

        send_to_thingspeak(distance)

        if distance < 10:  
            activate_buzzer()

        time.sleep(0.5) 

except KeyboardInterrupt:
    trig_pin.deinit()
    echo_pin.deinit()
    buzzer_pin.deinit()