import rp2
from rp2 import PIO
from machine import Pin
from time import sleep

@rp2.asm_pio(set_init=[PIO.IN_HIGH]*4)
def keypad():
    wrap_target()
    set(y, 0)
    label("scan")
    mov(isr, null)
    set(pindirs, 1)
    in_(pins, 4)
    set(pindirs, 2)
    in_(pins, 4)
    set(pindirs, 4)
    in_(pins, 4)
    set(pindirs, 8)
    in_(pins, 4)
    mov(x, isr)
    jmp(x_not_y, "changed")
    jmp("scan")
    label("changed")
    push(block)
    irq(0)
    mov(y, x)
    jmp("scan")
    wrap()

for i in range(10, 14):
    Pin(i, Pin.IN, Pin.PULL_DOWN)

key_names = "*7410852#963DCBA"

last_pressed = 0

def oninput(sm):
    global last_pressed
    keys = sm.get()
    while sm.rx_fifo():
        keys = sm.get()
   
    new_presses = keys & ~last_pressed
    last_pressed = keys
    if new_presses:  
        pressed = []
        for i in range(len(key_names)):
            if new_presses & (1 << i):
                pressed.append(key_names[i])
        print("Key pressed:", pressed)

sm = rp2.StateMachine(0, keypad, freq=2000,
                      in_base=Pin(10, Pin.IN, Pin.PULL_DOWN),
                      set_base=Pin(6))
sm.active(1)
sm.irq(oninput)

print("Press any key on the keypad (press Ctrl+C to stop).")
while True:
    sleep(0.1)