from machine import Pin, ADC
import time

first_digit = 7
Dot = 11

Codes = [
    0xC0,
    0xF9,
    0xA4,
    0xB0,
    0x99,
    0x92,
    0x82,
    0xF8,
    0x80,
    0x90
]

Display = 0

def Read_voltage(pin):
    global Display
    Analog = ADC(pin).read_u16()
    Display = round(3.3 * Analog / 65535 * 1000)
    print(f"V: {Display} mV")

def Scan():
    Current_value = Display
    for i in range(3, -1, -1):
        dp = (i == 0)
        display_digit(int(Current_value % 10), i, dp)
        time.sleep(1 / 60)
        Pin(first_digit + i, Pin.OUT).off()
        Pin(Dot, Pin.OUT).value(1)
        Current_value //= 10

def display_digit(digit_value, digit_index, dp_enable=False):
    for i in range(7):
        Pin(i, Pin.OUT).value((Codes[digit_value] >> i) & 1)
    Pin(first_digit + digit_index, Pin.OUT).on()
    Pin(Dot, Pin.OUT).value(0 if dp_enable else 1)

old_time = time.ticks_add(time.ticks_ms(), -280)
new_voltage = False

def interrupt_callback(pin):
    global old_time, new_voltage
    if time.ticks_diff(time.ticks_ms(), old_time) > 200:
        old_time = time.ticks_ms()
        new_voltage = True

def main():
    global new_voltage

    for i in range(4):
        Pin(first_digit + i, Pin.OUT).value(0)

    Pin(Dot, Pin.OUT).value(1)

    button = Pin(16, Pin.IN, Pin.PULL_DOWN)
    button.irq(trigger=Pin.IRQ_FALLING, handler=interrupt_callback)

    while True:
        if new_voltage:
            Read_voltage(26)
            new_voltage = False
        Scan()

if __name__ == '__main__':
    main()