from machine import Pin
import time

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

rows = [Pin(p, Pin.OUT) for p in [23,22,21,19]]
cols = [Pin(p, Pin.IN, Pin.PULL_UP) for p in [5,4,2,15]]

for r in rows:
    r.value(1)  # repouso HIGH

print("iniciou - segure uma tecla")

while True:
    for i, r in enumerate(rows):
        r.value(0)
        time.sleep_ms(2)
        for j, c in enumerate(cols):
            if c.value() == 0:
                print("Tecla:", KEYMAP[i][j])
                time.sleep_ms(300)
                t0 = time.ticks_ms()
                while c.value() == 0 and time.ticks_diff(time.ticks_ms(), t0) < 2000:
                    time.sleep_ms(20)
        r.value(1)
    time.sleep_ms(20)