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Lock Door System

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Joined: 22 Feb 2018
Posts: 5

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Lock Door System
PostPosted: Fri Mar 02, 2018 4:45 pm     Reply with quote

Hi, I want to do lock door system. I used 16f877a and 4*3 keypad. It work on proteus well but I created circuit on board and i wrote ccs c code for project.
When i enter the key it says key is wrong even if i enter right key. I tried 10 times but it says right key 2 or 3 times. For example i push a number but it doesn't take it sometimes, sometimes take after pushed number etc. I think delays were problem but i didn't find problem. Should I push number fastly or slowly? I don't understand problem. Can anyone help me ?

#include <16F877A.h>

#FUSES NOWDT                   
#FUSES NOBROWNOUT               
#FUSES NOLVP                   

#use delay(crystal=4000000)

#define LCD_RS_PIN PIN_B7
#define LCD_RW_PIN PIN_B6
#define LCD_DATA4 PIN_B4
#define LCD_DATA5 PIN_B3
#define LCD_DATA6 PIN_B2
#define LCD_DATA7 PIN_B1

#include "lcd.c"
#define sut1 pin_d0
#define sut2 pin_d1
#define sut3 pin_d2
#define sut4 pin_d3
#define sat1 pin_d4
#define sat2 pin_d5
#define sat3 pin_d6
#define sat4 pin_d7

#define ROLE pin_c0

 char tus=0;
 int basildi;
 int sifre[4];

char keypad_oku()
 tus = "";
 if (input(sut1))
 { delay_ms(500); tus=1;basildi=1; }
 if (input(sut2))
 { delay_ms(500); tus=2;basildi=1; }
 if (input(sut3))
 { delay_ms(500); tus=3;basildi=1; }
 if (input(sut4))
 { delay_ms(500); tus=0xA;basildi=1; }
 if (input(sut1))
 { delay_ms(500); tus=4;basildi=1;}
 if (input(sut2))
 { delay_ms(500); tus=5;basildi=1; }
 if (input(sut3))
 { delay_ms(500); tus=6;basildi=1; }
 if (input(sut4))
 { delay_ms(500); tus=0xB;basildi=1; }
 if (input(sut1))
 { delay_ms(500); tus=7;basildi=1; }
 if (input(sut2))
 { delay_ms(500); tus=8;basildi=1; }
 if (input(sut3))
 { delay_ms(500); tus=9;basildi=1; }
 if (input(sut4))
 {delay_ms(500); tus=0x0C;basildi=1; }
 if (input(sut1))
 { delay_ms(500); tus=0xE;basildi=1; }
 if (input(sut2))
 { delay_ms(500); tus=0;basildi=1; }
 if (input(sut3))
 { delay_ms(500); tus=0xF;basildi=1; }
 if (input(sut4))
 {delay_ms(500); tus=0xD;basildi=1; }

 return tus;

void main ( )
 printf(lcd_putc,"\fLock Door");
  printf(lcd_putc,"\fEnter Key");
 // Our system's Key
 sifre[0] = 1;
 sifre[1] = 9;
 sifre[2] = 8;
 sifre[3] = 7;
 int sec=0;
 int yanlis = 0;
 int gelen;
gelen = keypad_oku();
if (basildi==1) {

   if (sifre[sec] != gelen)
   if (sifre[sec] == gelen)
      if (sec>3) {
      if (yanlis==0) {
      printf(lcd_putc,"\fRight Key");
      printf(lcd_putc,"\fEnter key");
      else {
      printf(lcd_putc,"\fWrong Key");
      printf(lcd_putc,"\fEnter key");



Joined: 01 Jul 2010
Posts: 5880
Location: Greensville,Ontario

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PostPosted: Fri Mar 02, 2018 7:23 pm     Reply with quote

You need to look at the CCS example keypad program as well as the 'flex_kbd' program, maybe google 'scanning keypad algorithm'.
You need to understand that the keypad is a collection of mechnical switches and each switch requires 'debounce'. If you have access to an oscilloscope, connect it to a switch and observe the waveform when you press and release the button. You will NOT see nice square edged 0-1-0 transitions. That's why you need to add 'debounce'. A term used to describe the action to 'clean up' or change that noisey 0-1-0 transition into a clean, fast 'square wave'.
Debounce can be done with hardware (typically selected values of Rs and Cs, chips), software (calculated time delays, timed loops) or a combination of both.

I do suggest, if you intend to pursue electronics as a hobby, especially PICs or 'microcomputers', that you purchase an oscilloscope. Even a 20MHz, 2 channel, CRT type will be of great benefit to you.

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