import keypad as key
import lcd4bit as lcd
from utime import sleep
pwd="5678"
sleep(0.1)
print("start")
lcd.strwrite("insert password")
passin=""
while 1:
    a=key.getkey()
    if a!=0:
        print(a)
        if a=='#':
            if passin==pwd:
                lcd.cmdwrite(0x80)
                lcd.strwrite("correct password")
            else:
                lcd.cmdwrite(0x80)
                lcd.strwrite("wrong   password")
            passin=""
        elif a=='*':
            lcd.cmdwrite(0x01)
            lcd.strwrite("insert password")
            passin=""  #reset variable 
        else:
            passin+=a
            print(passin)
            lcd.cmdwrite(0xc4)
            lcd.strwrite("           ")
            lcd.cmdwrite(0xc4)
            for i in passin:
                lcd.strwrite('*')                     
    sleep(0.3)
    

main.py

diagram.json

from machine import Pin
from utime import sleep

row=(Pin(15,Pin.OUT),Pin(14,Pin.OUT),Pin(13,Pin.OUT),
     Pin(12,Pin.OUT))
col=(Pin(11,Pin.IN,Pin.PULL_UP),Pin(10,Pin.IN,Pin.PULL_UP),
     Pin(9,Pin.IN,Pin.PULL_UP))

label="123456789*0#"

def getkey():
    val=0
    for j in range (4):
        for i in row:
            i.value(1)
        row[j].value(0)
        for i in range(3):
            if col[i].value()==0:
                val=label[i+j*3]
                sleep(0.1)
                while col[i].value()==0:
                    pass
         
    return val




keypad.py

from machine import Pin
from utime import sleep

rs=Pin(21,Pin.OUT)
e=Pin(20,Pin.OUT)
dataline=(Pin(19,Pin.OUT),Pin(18,Pin.OUT),
          Pin(17,Pin.OUT),Pin(16,Pin.OUT))

def write(val):
    for i in range(4):
        dataline[i].value(((val>>4)&(0x01<<i))>>i)
    e.value(0)
    sleep(0.001)
    e.value(1)
    sleep(0.001)
    e.value(0)
    sleep(0.001)
    for i in range(4):
        dataline[i].value(((val)&(0x01<<i))>>i)
    e.value(0)
    sleep(0.001)
    e.value(1)
    sleep(0.001)
    e.value(0)
    sleep(0.001)
  
def datawrite(val):
    rs.value(1)
    write(val)

def cmdwrite(val):
    rs.value(0)
    write(val)
    sleep(0.01)

def startlcd():
    cmdwrite(0x02)
    sleep(0.01)
    cmdwrite(0x28)
    sleep(0.01)
    cmdwrite(0x0c)
    sleep(0.01)
    cmdwrite(0x01)
    sleep(0.01)
    cmdwrite(0x80)
    sleep(0.01)

def strwrite(word):
    for i in word:
        datawrite(ord(i))

def zfl(s, width):
# Pads the provided string with leading 0's to suit the specified 'chrs' length
# Force # characters, fill with leading 0's
    return '{:0>{w}}'.format(s, w=width)

startlcd()




