from machine import Pin
import time

# -------------------------------
# Keypad configuration (4x4)
# -------------------------------
rows = [
    Pin(2, Pin.OUT, Pin.PULL_DOWN),
    Pin(3, Pin.OUT, Pin.PULL_DOWN),
    Pin(4, Pin.OUT, Pin.PULL_DOWN),
    Pin(5, Pin.OUT, Pin.PULL_DOWN)
    ]

cols = [
    Pin(6, Pin.IN, Pin.PULL_DOWN),
    Pin(7, Pin.IN, Pin.PULL_DOWN),
    Pin(8, Pin.IN, Pin.PULL_DOWN),
    Pin(9, Pin.IN, Pin.PULL_DOWN)
    ]

keys = [
    ['1', '2', '3', 'A'],
    ['4', '5', '6', 'B'],
    ['7', '8', '9', 'C'],
    ['*', '0', '#', 'D']
]

# -------------------------------
# LED configuration (8 LEDs)
# -------------------------------
led_pins = [
    Pin(10, Pin.OUT, Pin.PULL_DOWN),
    Pin(11, Pin.OUT, Pin.PULL_DOWN),
    Pin(12, Pin.OUT, Pin.PULL_DOWN),
    Pin(13, Pin.OUT, Pin.PULL_DOWN),
    Pin(14, Pin.OUT, Pin.PULL_DOWN),
    Pin(15, Pin.OUT, Pin.PULL_DOWN),
    Pin(16, Pin.OUT, Pin.PULL_DOWN),
    Pin(17, Pin.OUT, Pin.PULL_DOWN),

    ]

# -------------------------------
# Helper functions
# -------------------------------
def clear_leds():
    for led in led_pins:
        led.value(0)

def all_leds_on():
    for led in led_pins:
        led.value(1)

def display_binary(value):
    """
    Display an integer value in 8-bit binary on LEDs
    """
    for i in range(8):
        led_pins[i].value((value >> i) & 1)

# -------------------------------
# Keypad scanning function
# -------------------------------
def read_key():
    for r in range(4):
        rows[r].value(1)
        for c in range(4):
            if cols[c].value() == 1:
                rows[r].value(0)
                return keys[r][c]
        rows[r].value(0)
    return None

# -------------------------------
# Main loop
# -------------------------------
while True:
    key = read_key()
    
    if key:
        print("Key pressed:", key)

        if key.isdigit():
            # Convert digit to integer and show binary
            value = int(key)
            clear_leds()
            display_binary(value)

        else:
            # Special characters (*, #, A–D)
            all_leds_on()

        time.sleep(0.3)  # debounce delay