from machine import Pin
import time 

RPINS=[2,3,4,5]
CPINS=[6,7,8,9]

KEYMAP=[
    ['1','2','3','A'],
    ['4','5','6','B'],
    ['7','8','9','C'],
    ['*','0','#','D']
]
rows=[Pin(r,Pin.OUT) for r in RPINS]

for counter in rows:
    counter.value(0)

clos=[Pin(c,Pin.IN,Pin.PULL_DOWN) for c in CPINS]

led=Pin(25,Pin.OUT)

def readKeypad():
    for i,rpin in enumerate(rows):
        rpin.value(1)

        for j,cpin in enumerate(clos):
           if cpin.value()==1:
            time.sleep_ms(50)
            if cpin.value()==1:
                return KEYMAP[i][j]
        rpin.value(0)
    return None
print("Keypad ready.Press a key...")
while True:
    key=readKeypad()
    if key:
        print(f"key Pressed:{key}")
        led.toggle()
        time.sleep_ms(200)
    time.sleep_ms(50)