from machine import Pin
import time

# ==== GPIO Pins on ESP32 ====
DATA = Pin(23, Pin.OUT)    # Serial Data Input (DS)
LATCH = Pin(18, Pin.OUT)   # Latch Clock (ST_CP)
CLOCK = Pin(19, Pin.OUT)   # Shift Register Clock (SH_CP)

# ==== Segment Byte Codes (Common Cathode 7-segment: 0-9) ====
digits = [
    0b11000000,  # 0
    0b11111001,  # 1
    0b10100100,  # 2
    0b10110000,  # 3
    0b10011001,  # 4
    0b10010010,  # 5
    0b10000010,  # 6
    0b11111000,  # 7
    0b10000000,  # 8
    0b10010000   # 9
]

# ==== Digit Select Bitmasks for each of 4 digits ====
digit_masks = [
    0b00001000,  # Digit 1 (leftmost)
    0b00000100,  # Digit 2
    0b00000010,  # Digit 3
    0b00000001   # Digit 4 (rightmost)
]

# ==== Helper: Shift out 1 byte MSB first ====
def shift_out(byte):
    for i in range(8):
        bit = (byte >> (7 - i)) & 1
        DATA.value(bit)
        CLOCK.value(1)
        CLOCK.value(0)

# ==== Pads number string to 4 digits with leading zeros ====
def pad_left_zeros(s, length=4):
    return '0' * (length - len(s)) + s

# ==== Main Display Function for 10 displays ====
def display_all(d1, d2, d3, d4, d5, d6, d7, d8, d9, d10):
    vals = [pad_left_zeros(str(x)) for x in [d1, d2, d3, d4, d5, d6, d7, d8, d9, d10]]

    for pos in range(4):  # For each digit position (0 to 3)
        seg_data = digits[int(vals[0][pos])] if vals[0][pos].isdigit() else 0xFF
        shift_out(seg_data)  # 1st IC: Segment byte

        # Now push digit control data for IC2–IC11 (Displays 1–10)
        for i in range(10):
            ch = vals[i][pos]
            digit_val = digit_masks[pos] if ch.isdigit() else 0x00
            shift_out(digit_val)

        LATCH.value(0)
        LATCH.value(1)
        time.sleep_ms(1)  # Small delay for multiplexing

# ==== Test Display Values ====
# You can set any 4-digit number per display here
disp_vals = [1234, 5678, 2025, 9999, 3141, 8080, 1111, 4242, 7777, 1010]

# ==== Main Loop ====
while True:
    for _ in range(100):  # Refresh screen to keep display stable
        display_all(*disp_vals)