from machine import Pin
import utime

# Define shift register pins for segment control
SEG_DATA = Pin(0, Pin.OUT)
SEG_CLOCK = Pin(1, Pin.OUT)
SEG_LATCH = Pin(2, Pin.OUT)

# Define shift register pins for digit selection
DIGIT_DATA = Pin(3, Pin.OUT)
DIGIT_CLOCK = Pin(4, Pin.OUT)
DIGIT_LATCH = Pin(5, Pin.OUT)

# 7-segment display binary values (common cathode)
SEGMENT_MAP = {
    '0': 0b00111111, '1': 0b00000110, '2': 0b01011011, '3': 0b01001111,
    '4': 0b01100110, '5': 0b01101101, '6': 0b01111101, '7': 0b00000111,
    '8': 0b01111111, '9': 0b01101111, ' ': 0b00000000
}

# Digit selection map (Active-Low, enables one digit at a time)
DIGIT_MAP = [0b1110, 0b1101, 0b1011, 0b0111]  # Only one bit LOW at a time

def shift_out(value, data_pin, clock_pin):
    """Shift out 8-bit data to a shift register"""
    for i in range(8):
        bit = (value >> (7 - i)) & 1
        data_pin.value(bit)
        clock_pin.value(1)
        utime.sleep_us(1)
        clock_pin.value(0)

def latch(latch_pin):
    """Latch the data to output the bits"""
    latch_pin.value(1)
    utime.sleep_us(1)
    latch_pin.value(0)

def display_digits(digits, duration=300):
    """Display a 4-digit number correctly using multiplexing"""
    start_time = utime.ticks_ms()
    while utime.ticks_ms() - start_time < duration:  # Display for given duration
        for i in range(4):
            shift_out(0b00000000, SEG_DATA, SEG_CLOCK)  # Clear segments
            shift_out(0b1111, DIGIT_DATA, DIGIT_CLOCK)  # Disable all digits
            latch(SEG_LATCH)
            latch(DIGIT_LATCH)
            
            # Send new data
            shift_out(SEGMENT_MAP[digits[i]], SEG_DATA, SEG_CLOCK)  # Send segment data
            shift_out(DIGIT_MAP[i], DIGIT_DATA, DIGIT_CLOCK)  # Activate current digit
            latch(SEG_LATCH)  # Update segment display
            latch(DIGIT_LATCH)  # Update digit selection
            
            utime.sleep_ms(5)  # Short delay for multiplexing

def scroll_number(number, scroll_speed=300):
    """Scroll a number smoothly across the display"""
    str_num = str(number)  # Convert number to string
    str_num = " " * 4 + str_num + " " * 4  # Add padding for smooth scroll

    for i in range(len(str_num) - 3):  # Shift through characters
        display_digits(str_num[i:i+4], scroll_speed)


def zero_pad(num, digit, width=4):
    """Ensure the number is formatted as a 4-digit string"""
    str_num = str(num)
    if digit==True:
        return "0" * (width - len(str_num)) + str_num
    else:
        return " " * (width - len(str_num)) + str_num

def display_number(number, disp=False, duration=1000):
    """Display a 4-digit number correctly using multiplexing"""
    padded_num = zero_pad(number, disp, 4)  # Ensure 4-digit format
    start_time = utime.ticks_ms()

    while utime.ticks_ms() - start_time < duration:  # Display for given duration
        for i in range(4):
            shift_out(0b00000000, SEG_DATA, SEG_CLOCK)  # Clear segments
            shift_out(0b1111, DIGIT_DATA, DIGIT_CLOCK)  # Disable all digits
            latch(SEG_LATCH)
            latch(DIGIT_LATCH)
            
            # Send new data
            shift_out(SEGMENT_MAP[padded_num[i]], SEG_DATA, SEG_CLOCK)  # Send segment data
            shift_out(DIGIT_MAP[i], DIGIT_DATA, DIGIT_CLOCK)  # Activate current digit
            latch(SEG_LATCH)  # Update segment display
            latch(DIGIT_LATCH)  # Update digit selection
            
            utime.sleep_ms(5)  # Short delay for multiplexing

# Test cases: Display different numbers correctly
while True:
    display_number(1234)  # Show 1234 for 1 sec
    display_number(5678)  # Show 5678 for 1 sec
    display_number(90)    # Show 0090 for 1 sec
    display_number(42)    # Show 0042 for 1 sec
    scroll_number(15479865646)