import machine
import time

# SEGMENT PINS → GP0–GP7 (A to DP)
SEGMENT_PINS = [
    machine.Pin(0, machine.Pin.OUT),  # A
    machine.Pin(1, machine.Pin.OUT),  # B
    machine.Pin(2, machine.Pin.OUT),  # C
    machine.Pin(3, machine.Pin.OUT),  # D
    machine.Pin(4, machine.Pin.OUT),  # E
    machine.Pin(5, machine.Pin.OUT),  # F
    machine.Pin(6, machine.Pin.OUT),  # G
    machine.Pin(7, machine.Pin.OUT),  # DP
]

# DIGIT PINS (REVERSED ORDER) → GP11 to GP8 (DIG1–DIG4)
DIGIT_PINS = [
    machine.Pin(11, machine.Pin.OUT),  # DIG1 (leftmost)
    machine.Pin(10, machine.Pin.OUT),  # DIG2
    machine.Pin(9, machine.Pin.OUT),   # DIG3
    machine.Pin(8, machine.Pin.OUT),   # DIG4 (rightmost)
]

# BUTTON + ANALOGUE
BUTTON_PIN = 16
ADC_PIN = 26

# Segment map for 0-9 (A to G)
SEGMENT_MAP = {
    0: 0b00111111,  # A B C D E F
    1: 0b00000110,  # B C
    2: 0b01011011,  # A B D E G
    3: 0b01001111,  # A B C D G
    4: 0b01100110,  # B C F G
    5: 0b01101101,  # A C D F G
    6: 0b01111101,  # A C D E F G
    7: 0b00000111,  # A B C
    8: 0b01111111,  # All
    9: 0b01101111,  # A B C D F G
}

display_value = 0.0  # Global voltage to show

def read_analogue_voltage(pin):
    adc = machine.ADC(pin)
    raw_value = adc.read_u16()
    voltage = (raw_value / 65535) * 3.3
    return round(voltage, 3)

def handle_button_interrupt(pin):
    global display_value
    display_value = read_analogue_voltage(ADC_PIN)
    print("Button pressed! Voltage =", display_value)

button = machine.Pin(BUTTON_PIN, machine.Pin.IN, machine.Pin.PULL_UP)
button.irq(trigger=machine.Pin.IRQ_FALLING, handler=handle_button_interrupt)

def display_digit(digit_value, digit_index):
    segment_value = SEGMENT_MAP.get(digit_value, 0)

    for pin in SEGMENT_PINS:
        pin.value(1)  # OFF (Common Anode)

    for i in range(7):
        if segment_value & (1 << i):
            SEGMENT_PINS[i].value(0)  # ON

    for pin in DIGIT_PINS:
        pin.value(1)  # All OFF
    DIGIT_PINS[digit_index].value(0)  # Enable current digit

def scan_display(timer):
    global display_value
    voltage_str = "{:.3f}".format(display_value).replace(".", "")
    
    # Pad to 4 digits manually (NO ljust)
    while len(voltage_str) < 4:
        voltage_str += "0"
    voltage_str = voltage_str[:4]

    digits = [int(d) for d in voltage_str]

    for i in range(4):
        display_digit(digits[i], i)
        time.sleep(0.002)


    for i in range(4):
        display_digit(digits[i], i)
        time.sleep(0.002)

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

def setup():
    enable_display_timer()

if __name__ == '__main__':
    setup()
    while True:
        time.sleep(1)