from machine import Pin
import time

reng = [0,1,2,3]
cols = [12,13,14,15]

renglones = []
columnas = []

for i in range(4):
  renglones.append(Pin(reng[i], Pin.OUT))
  columnas.append(Pin(cols[i], Pin.IN, Pin.PULL_DOWN))
  renglones[i].value(0)

def teclado():
  key = False
  r = 0
  while r < 4 and key is False:
    renglones[r].value(1)
    c = 0
    while c < 4 and key is False:
      if columnas[c].value() == 1:
        key = True
        renglones[r].value(0)
      else:
        c += 1
    if key is False:
      renglones[r].value(0)
      r += 1
  return r, c

while True:
  print(teclado())
  time.sleep(1)