import machine
import time, sys

sev_seg = 0
sev_seg_digit = 8
display_value = 0
counter = None
prev_display_value = 0

digits = [
    [0, 1, 1, 1, 1, 1, 1], # 0
    [0, 0, 0, 0, 1, 1, 0], # 1
    [1, 0, 1, 1, 0, 1, 1], # 2
    [1, 0, 0, 1, 1, 1, 1], # 3
    [1, 1, 0, 0, 1, 1, 0], # 4
    [1, 1, 0, 1, 1, 0, 1], # 5
    [1, 1, 1, 1, 1, 0, 1], # 6
    [0, 0, 0, 0, 1, 1, 1], # 7
    [1, 1, 1, 1, 1, 1, 1], # 8
    [1, 1, 0, 1, 1, 1, 1], # 9
    [1, 1, 1, 0, 1, 1, 1], # A
    [1, 1, 1, 1, 1, 0, 0], # B
    [0, 1, 1, 1, 0, 0, 1], # C
    [1, 0, 1, 1, 1, 1, 0], # D
    [1, 1, 1, 1, 0, 0, 1], # E
    [1, 1, 1, 0, 0, 0, 1], # F
]
# On and Off Switch
switch = machine.Pin(15, machine.Pin.IN)

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

# Function to enable timer that triggers scanning 7 segment displays
def enable_display_timer(x):
    x.init(period=90, mode=machine.Timer.PERIODIC, callback=scan_display)

# A function to adjust led brightness using PWM(Pulse With Modulation)
def PWM(x):
    pwm = machine.PWM(machine.Pin(21))
    pwm.freq(400000)
    pwm.duty_u16(x)

# Function to handle scanning 7 segment displays
# Display the value stored in the display_value global variable
# on available 7-segment displays
def scan_display(timer_int):
    global display_value, digit_pins
    display_value = machine.ADC(machine.Pin(26)).read_u16()
    m = int(((display_value * 3.3) / 65535) * 1000)
    for i in range(len(digit_pins)):
        display_digit(int(m % 10), i, i==3)
        seg_pins[7].off()
        digit_pins[i].on()
        m /= 10
    PWM(display_value)

# Function display the given value on the display with the specified index
# dp_enable specifies if the decimal pooint should be on or off
def display_digit(digit_value, digit_index, dp_enable=False):
    global seg_pins, digit_pins

    # Validity Check
    if 0 > digit_value or digit_value > len(digits):
        return
    
    # Display Digit
    val = digits[digit_value]
    for i in range(7):
        seg_pins[i].value(val[i])

    # Position of Digit
    if digit_index <= len(digit_pins):
        digit_pins[digit_index].off()
    else:
        for i in range(4):
            digit_pins[i].off()

    # Decimal Point Check
    if dp_enable:
        seg_pins[7].on()
    else:
        seg_pins[7].off()

def setup():
    global display_value, digit_pins, seg_pins, scanner
    time.sleep(0.02)

    # PINS (GPIO or ADC)
    a = machine.Pin(sev_seg, machine.Pin.OUT)
    b = machine.Pin(sev_seg + 1, machine.Pin.OUT)
    c = machine.Pin(sev_seg + 2, machine.Pin.OUT)
    d = machine.Pin(sev_seg + 3, machine.Pin.OUT)
    e = machine.Pin(sev_seg + 4, machine.Pin.OUT)
    f = machine.Pin(sev_seg + 5, machine.Pin.OUT)
    g = machine.Pin(sev_seg + 6, machine.Pin.OUT)
    dp = machine.Pin(sev_seg + 7, machine.Pin.OUT)
    dig1 = machine.Pin(sev_seg_digit + 3, machine.Pin.OUT)
    dig2 = machine.Pin(sev_seg_digit + 2, machine.Pin.OUT)
    dig3 = machine.Pin(sev_seg_digit + 1, machine.Pin.OUT)
    dig4 = machine.Pin(sev_seg_digit, machine.Pin.OUT)
    
    # segments and digits of seven segment display
    digit_pins = [dig1, dig2, dig3, dig4]
    seg_pins = [g, f, e, d, c, b, a, dp]

    # Timer setup
    scanner = machine.Timer()
    enable_display_timer(scanner)

if __name__ == "__main__":
    setup()