#r1=d1
#r2=15
#r3=2
#r4=0
#c1=4
#c2=16
#c3=17
#c4=4
from machine import Pin 
import utime
matrix_key=[["1", "2", "3","A"],
            ["4", "5", "6","B"], 
            ["7", "8", "9","C"],
            ["*", "0", "#","D"]]
key_row=[1, 15, 2, 0]
key_col=[4, 16, 17, 4]
col_pin=[]
row_pin=[]
for button in range(0, 4):
    row_pin.append(Pin(key_row[button], Pin.OUT))
    row_pin[x].value(1)
    col_pin.append(Pin(key_col[button], Pin.IN, Pin.PULL_DOWN))
    col_pin[x].value(0)
print("Please Enter a key")
def scanning():
    for row in range(4):
        for col in range(4):
            row_pin[row].on()
            key=None
            
            if col_pin[col].value()==1:
                print("Pressed", matrix_key[row][col])
                keypress=matrix_key[row][col]
                utime.sleep(0.3)
        row_pin[row].off()
while True:
    scanning()