from machine import Pin, I2C, ADC
import ssd1306
import time
import onewire, ds18x20

# ---------------- I2C (OLED) ----------------
i2c = I2C(0, scl=Pin(5), sda=Pin(4))
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# ---------------- DS18B20 ----------------
dat = Pin(15)
ow = onewire.OneWire(dat)
ds = ds18x20.DS18X20(ow)
roms = ds.scan()

# ---------------- Button ----------------
button = Pin(14, Pin.IN, Pin.PULL_UP)

# ---------------- Battery ----------------
adc = ADC(26)

# ---------------- TIME SET (CHANGE THIS) ----------------
START_HOUR = 18   # 👈 set your current time
START_MIN = 35
START_SEC = 0

start_ticks = time.ticks_ms()

def get_time():
    elapsed = time.ticks_diff(time.ticks_ms(), start_ticks) // 1000
    
    sec = START_SEC + elapsed
    minute = START_MIN + sec // 60
    hour = START_HOUR + minute // 60

    sec = sec % 60
    minute = minute % 60
    hour = hour % 24

    return hour, minute, sec

# ---------------- Variables ----------------
screen = 0
last_press = 0
last_activity = time.ticks_ms()

message = "Hello Arthi!"

# ---------------- Functions ----------------

def read_temp():
    ds.convert_temp()
    time.sleep_ms(750)
    for rom in roms:
        return ds.read_temp(rom)

def read_voltage():
    raw = adc.read_u16()
    voltage = (raw / 65535) * 3.3
    battery_voltage = voltage * 3   # simulate 0–9V
    return battery_voltage

def draw_screen():
    oled.fill(0)

    if screen == 0:
        h, m, s = get_time()
        oled.text("Time", 0, 0)
        oled.text("{:02}:{:02}:{:02}".format(h, m, s), 0, 20)

    elif screen == 1:
        temp = read_temp()
        oled.text("Temp", 0, 0)
        oled.text(str(round(temp, 1)) + " C", 0, 20)

    elif screen == 2:
        volt = read_voltage()
        oled.text("Battery", 0, 0)
        oled.text("{:.2f} V".format(volt), 0, 20)

        if volt < 6.5:
            oled.text("LOW!", 0, 40)

    elif screen == 3:
        oled.text("Message", 0, 0)
        oled.text(message, 0, 20)

    oled.show()

# ---------------- Main Loop ----------------

while True:
    # Button press
    if button.value() == 0:
        if time.ticks_diff(time.ticks_ms(), last_press) > 300:
            screen = (screen + 1) % 4
            last_press = time.ticks_ms()
            last_activity = time.ticks_ms()

    # Auto dim
    if time.ticks_diff(time.ticks_ms(), last_activity) > 30000:
        oled.contrast(0)
    else:
        oled.contrast(255)

    draw_screen()
    time.sleep(0.2)