import machine
import utime
import ssd1306
from machine import Pin, PWM, I2C

# Initialize I2C for OLED
i2c = I2C(0, scl=Pin(1), sda=Pin(0))  # Adjust pins if necessary
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# Initialize HC-SR04
trig = Pin(26, Pin.OUT)
echo = Pin(27, Pin.IN)

# Initialize Servo
servo = PWM(Pin(4))
servo.freq(50)  # Standard frequency for servos

# Define servo positions (in duty cycle)
OPEN_POSITION = 65535 * 0.5  # Adjust these values based on your servo
CLOSED_POSITION = 65535 * 0.2  # Adjust these values based on your servo

def get_distance():
    trig.low()
    utime.sleep_us(2)
    trig.high()
    utime.sleep_us(10)
    trig.low()

    while echo.value() == 0:
        pulse_start = utime.ticks_us()
    while echo.value() == 1:
        pulse_end = utime.ticks_us()

    pulse_duration = utime.ticks_diff(pulse_end, pulse_start)
    distance = pulse_duration * 0.0343 / 2  # Convert to cm
    return distance

def update_display(free_slots, gate_status):
    oled.fill(0)
    oled.text("Free Slots: {}".format(free_slots), 0, 0)
    oled.text("Gate: {}".format(gate_status), 0, 10)
    oled.show()

def control_gate(free_slots):
    if free_slots > 0:
        # Open gate
        servo.duty_u16(OPEN_POSITION)
        return "Open"
    else:
        # Close gate
        servo.duty_u16(CLOSED_POSITION)
        return "Closed"

def main():
    num_slots = 10  # Total number of parking slots
    occupied_slots = 0

    while True:
        free_slots = num_slots - occupied_slots
        distance = get_distance()

        if distance < 10:  # Adjust this threshold as needed
            occupied_slots += 1
            print("vehicle detected gate opening")
        else:
            occupied_slots = max(0, occupied_slots - 1)
            print("vehicle not detected")

        gate_status = int(control_gate(free_slots))
        update_display(free_slots, gate_status)
        
        utime.sleep(2)  # Check every 2 seconds

if __name__ == "__main__":
    main()