PIC Controle De Acesso

combination lock v2-025 for PIC16F628 with LCD

On popular request, I wrote the code for adding a 2x16 character HD44780-compatible LCD to this project.

software

In addition to the standard definitions, you may want to change these variables:

#define HIDDEN_CODE '*' this is the definition of what you see on the LCD instead of the digits (default is asterisk). If you delete this line, the digits are shown as entered

msg_line EQU 0x80 this value contains the LCD position for messages. By default it contains the address of the first LCD line (documented in the LCD datasheet)

code_line EQU 0xc0 this value contains the LCD position for code entry. By default it contains the address of the second LCD line (documented in the LCD datasheet)

schematic

This is not the whole schematic, you also need the serial LCD interface, which connects to the 6-pin connector 'serial LCD'.

code

description written by download

source code and HEX file with default settings Peter JAKAB cl2-025.zip

cl2-025.hex

HEX file, show entered digits in clear Peter JAKAB cl2-025b.hex

part list

The parts for the LCD interface are not included in this list.

part number description

IC1 PIC16F627 or

PIC16F628 or

PIC16F627A or

PIC16F628A - Microchip microcontroller, pre-programmed

IC2 78L05 or

7805 - 5V output voltage regulator

Q1 BC301 or similar npn bipolar transistor, Ic(min)=500 mA

D1 1N4001, 1N4004 or 1N4007 diode

LED1 any color LED or

3mm green LED

R1 1 kohm 1/4W resistor

R2 220 ohm 1/4W resistor

C3 100 nF ceramic capacitor

C4 100 nF ceramic capacitor

BUZZER ceramic piezo sounder

(also called 'piezo diaphragm', 'piezo audio transducer', 'piezo audio indicator')

keypad 3x4 or 4x4 matrix keypad

K1 relay, see text for specifications

lcdif serial LCD interface: an HD44780-compatibe 2x16 char LCD and some more electronics

lcdconn 6-pin header for connecting the LCD interface

misc power supply with 8-30V DC output - suggested voltage is 12VDC

connectors for the power supply and the keypad

Printed