from machine import Pin, ADC, Timer
from utime import sleep_ms, ticks_ms, ticks_diff
from math import log

adc_reader = ADC(26)
button1 = Pin(16, Pin.IN, Pin.PULL_UP)

maxVolts = 3.3
adc_res = 2**16

SEVEN_SEGMENT_START_PIN = 2
DISPLAY_COUNT = 4
DECIMAL_PRECISION = 3

digit_list_hex = [
    0x40,
    0x79,
    0x24,
    0x30,
    0x19,
    0x12,
    0x02,
    0x78,
    0x00,
    0x10, 
    0x08,
    0x03,
    0x46,
    0x21,
    0x06,
    0x0E,
    0x7F
]

seg_value = 0
seg_pins = [Pin(2), Pin(3), Pin(4), Pin(5), Pin(6), Pin(7), Pin(8), Pin(9)]
dig_pins = [Pin(13), Pin(12), Pin(11), Pin(10)]
current_display_index = DISPLAY_COUNT - 1
display_timer = None

debounce_delay = 100
last_button_state = button1.value()
last_button_time = 0

def disable_display_timer():
    global display_timer
    display_timer.deinit()

def enable_display_timer():
    global display_timer
    display_timer.init(period=30, mode=Timer.PERIODIC, callback=scan_display)

def scan_display(timer_int):
    global current_display_index, seg_value
    digit = int((seg_value * 1000 // pow(10, current_display_index))) % 10
    display_digit(digit, current_display_index, current_display_index == DECIMAL_PRECISION and 0 != DECIMAL_PRECISION)
    current_display_index = (current_display_index - 1)
    if current_display_index < 0:
        current_display_index = DISPLAY_COUNT - 1

def display_digit(digit_value, digit_index, dp_enable = False):
    if digit_value < 0 or digit_value > len(digit_list_hex):
        return
    for pin in dig_pins:
        pin.value(0)
    mask = digit_list_hex[digit_value]
    for i in range(7):
        seg_pins[i].value((mask >> i) & 1)
    seg_pins[7].value(1 if dp_enable == False else 0)
    if digit_index == -1:
        for pin in dig_pins:
            pin.value(1)
    elif 0 <= digit_index < DISPLAY_COUNT:
        dig_pins[digit_index].value(1)

def read_analogue_voltage(pin):
    return pin.read_u16()

def setup():
    global seg_pins, dig_pins
    global display_timer
    for i in range(SEVEN_SEGMENT_START_PIN + 8, SEVEN_SEGMENT_START_PIN + 8 + DISPLAY_COUNT):
        pin = Pin(i, Pin.OUT)
        pin.value(0)
        dig_pins.append(pin)
    for i in range(SEVEN_SEGMENT_START_PIN, SEVEN_SEGMENT_START_PIN + 8):
        pin = Pin(i, Pin.OUT)
        pin.value(1)
        seg_pins.append(pin)
    display_timer = Timer()
    enable_display_timer()

def handle_button_interrupt(pin):
    global last_button_state, last_button_time, seg_value
    current_time = ticks_ms()
    if ticks_diff(current_time, last_button_time) < debounce_delay:
        return
    last_button_time = current_time
    button_state = pin.value()
    if button_state != last_button_state:
        print("\nInterrupt triggered")
        last_button_state = button_state

        adc_reader_value = read_analogue_voltage(adc_reader)
        adc_reader_voltage = adc_reader_value / (adc_res-1) * maxVolts
        adc_reader_value2 = read_analogue_voltage(adc_reader2)
        adc_reader_voltage2 = adc_reader_value2 / (adc_res-1) * maxVolts
        seg_value = adc_reader_voltage
        print(f"Voltage: {adc_reader_voltage} volts")
        print(f"Voltage 2: {adc_reader_voltage2} volts (Value: {adc_reader_value2})")


def main():
    button1.irq(trigger=Pin.IRQ_FALLING, handler=handle_button_interrupt)

if __name__ == '__main__':
    setup()
    main()