import utime
from machine import I2C, Pin, Timer
from pico_i2c_lcd import I2cLcd

trigger_pins = [Pin(2, Pin.OUT),
                Pin(4, Pin.OUT),
                Pin(6, Pin.OUT)]

echo_pins = [Pin(3, Pin.IN),
             Pin(5, Pin.IN),
             Pin(7, Pin.IN)]

threshold_distance = 100

i2c = I2C(0, sda=Pin(0), scl=Pin(1), freq=400000)
lcd = I2cLcd(i2c, 0x27, 2, 16)

detected_room = None

def get_distance(trigger, echo):
    trigger.value(0)
    utime.sleep_us(2)
    trigger.value(1)
    utime.sleep_us(10)
    trigger.value(0)
    
    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
    return distance

def update_lcd():
    lcd.clear()
    lcd.move_to(0, 0)
    if detected_room:
        lcd.putstr("Motion detected in")
        lcd.move_to(0, 1)
        lcd.putstr(detected_room)

def check_rooms(t):
    global detected_room
    
    distance_room1 = get_distance(trigger_pins[0], echo_pins[0])
    if distance_room1 < threshold_distance:
        detected_room = "Room 1"
        update_lcd()
        return
    
    distance_room2 = get_distance(trigger_pins[1], echo_pins[1])
    if distance_room2 < threshold_distance:
        detected_room = "Room 2"
        update_lcd()
        return
    
    distance_room3 = get_distance(trigger_pins[2], echo_pins[2])
    if distance_room3 < threshold_distance:
        detected_room = "Room 3"
        update_lcd()
        return
    
    detected_room = None
    update_lcd()

tim = Timer(mode=Timer.PERIODIC, freq=1, callback=check_rooms)