from machine import Pin, ADC, Timer
import time
import math

Seven_Segment = [0, 1, 2, 3, 4, 5, 6]
digit_pins = [11, 10, 9, 8]
dp = Pin(7, Pin.OUT)

button = 16
pot_pin = 26
temp_pin = 27
light_pin = 28

adc_pot = ADC(Pin(pot_pin))
adc_temp = ADC(Pin(temp_pin))
adc_light = ADC(Pin(light_pin))

displayCodes =[
    0x3F,
    0x06,
    0x5B,
    0x4F,
    0x66,
    0x6D,
    0x7D,
    0x07,
    0x7F,
    0x6F,
    0x40,
    0x00
]

display_buffer = [' ', ' ', ' ', ' ']
current_digit = 0
last_button_press = 0
debouncing = 200
mode = 0 

segments = [Pin(d, Pin.OUT) for d in Seven_Segment]
digits = [Pin(d, Pin.OUT) for d in digit_pins]
display_timer = Timer()

def read_voltage():
    raw = adc_pot.read_u16()
    voltage = (raw / 65535) * 3.3
    return voltage  # float

def read_temperature():
    BETA = 3950
    raw = adc_temp.read_u16()
    voltage = raw * 3.3 / 65535
    resistance = 10000 / (3.3 / voltage - 1)
    temp = 1 / (math.log(resistance / 10000) / BETA + 1 / 298.15) - 273.15
    return int(temp)

def read_light():
    raw = adc_light.read_u16()
    percent = (raw / 65535) * 100
    return int(percent)

def update_display(voltage=None, temp=None, light=None):
    global display_buffer
    dp.value(1)  # Turn OFF decimal point by default

    if voltage is not None:
        val = f"{voltage:.2f}".replace('.', '')[:3].rjust(3)
        display_buffer = list(val + ' ')
        dp.value(0)  # Turn ON decimal point between digit 2 and 3

    elif temp is not None:
        val = str(temp).rjust(3)
        display_buffer = list(val)

    elif light is not None:
        val = str(light).rjust(3)
        display_buffer = list(val)

def display_digit(timer):
    global current_digit
    for d in digits:
        d.value(0)

    char = display_buffer[current_digit]
    pattern = displayCodes(char, 0x00)

    for i in range(7):
        segments[i].value((pattern >> i) & 1)

    if current_digit == 2 and dp.value() == 0:
        dp.value(0)
    else:
        dp.value(1)

    digits[current_digit].value(1)
    current_digit = (current_digit + 1) % 4

def button_handler(pin):
    global last_button_press, mode
    now = time.ticks_ms()
    if time.ticks_diff(now, last_button_press) > debouncing:
        last_button_press = now
        mode = (mode + 1) % 3

        if mode == 0:
            val = read_voltage()
            print(f"Voltage: {val:.2f} V")
            update_display(voltage=val)
        elif mode == 1:
            val = read_temperature()
            print(f"Temperature: {val} °C")
            update_display(temp=val)
        elif mode == 2:
            val = read_light()
            print(f"Light: {val}%")
            update_display(light=val)

def enable_display_timer():
    display_timer.init(period=5, mode=Timer.PERIODIC, callback=display_digit)

def setup():
    enable_display_timer()
    button_pin = Pin(button, Pin.IN, Pin.PULL_DOWN)
    button_pin.irq(trigger=Pin.IRQ_RISING, handler=button_handler)
    print("Ready. Press the button to switch display mode.")

if __name__ == '__main__':
    setup()
    try:
        while True:
            time.sleep(0.1)
    except KeyboardInterrupt:
        display_timer.deinit()
        for digit in digits:
            digit.value(0)
        print("Program stopped.")