import time
import board
import digitalio

# Define ultrasonic sensor pins
trigger_pins = [board.GP14, board.GP16, board.GP18]
echo_pins = [board.GP15, board.GP17, board.GP19]

# Define pulse output pins for the sensors
led_pins = [board.GP20, board.GP21, board.GP22]
leds = [digitalio.DigitalInOut(pin) for pin in led_pins]
for led in leds:
    led.direction = digitalio.Direction.OUTPUT

# Define ultrasonic sensor objects
sensors = []
for trig, echo in zip(trigger_pins, echo_pins):
    trigger = digitalio.DigitalInOut(trig)
    trigger.direction = digitalio.Direction.OUTPUT
    echo = digitalio.DigitalInOut(echo)
    echo.direction = digitalio.Direction.INPUT
    sensors.append((trigger, echo))

# Loop to read distances from the sensors
d=[]
val=0
while True:
    for i, (trigger, echo) in enumerate(sensors):
        # Send a 10us trigger signal
        trigger.value = False
        time.sleep(0.0001)
        trigger.value = True
        time.sleep(0.00001)
        trigger.value = False

        # Measure the duration of the echo pulse
        pulse_start = 0
        while echo.value == False:
            pulse_start = time.monotonic_ns()
        pulse_end = 0
        while echo.value == True:
            pulse_end = time.monotonic_ns()
        pulse_duration = pulse_end - pulse_start

        # Calculate the distance in cm
        distance = pulse_duration / 58000

        # Print the distance and adjust LED brightness based on distance
        print("Sensor {} distance: {}".format(i+1, distance))
        leds[i].value = distance <= 20
        d.append(distance)
    if(d[2] <= 50):
         val=3
    elif(d[1] <= 50):
        val=2
    elif(d[0] <= 50):
        val=1
    
    time.sleep(5)
    print("value to be uploaded to thingspeak is",val)
    val=0
    d.clear()