First of all, let’s take a look at this circuit.
So, the components that are used here : 12 buttons , 7 resistances , 3 light-emitting diodes (LED) , 1 inverter , 1 logic gate AND , one logic gate OR, one switch to simulate the lock and of course the most important component is the PIC16F917 micro-controller.
I will show you a simulation of how this digital lock works :
Digital Lock Simulation with Proteus from Horia Condrea on Vimeo.
The code for the micro-controller :
volatile int gv_nInc= 0;
volatile int gv_nFirstLine=0;
volatile int gv_nSecondLine=0;
volatile int gv_nThirdLine=0;
volatile int gv_nFourthLine=0;
volatile int gv_nCounter=0;
const char* const gc_pPass = "157";
char gv_pInputPass[3];
volatile int gv_nCursor = 0;
volatile int gv_nSystemCounter = 0;
void interrupt()
{
INTCON.GIE = 0;
if(INTCON.T0IF)
{
gv_nCounter++;
gv_nSystemCounter++;
INTCON.T0IF=0;
TMR0=99;
}
if(INTCON.RBIF)
{
if(PORTB.RB4)
{
gv_nFirstLine = 1;
gv_nSecondLine=0;
gv_nThirdLine=0;
gv_nFourthLine=0;
PORTB.RB4=0;
Delay_ms(100);
}
if(PORTB.RB5)
{
gv_nFirstLine=0;
gv_nSecondLine=1;
gv_nThirdLine=0;
gv_nFourthLine=0;
PORTB.RB5=0;
Delay_ms(100);
}
if(PORTB.RB6)
{
gv_nFirstLine = 0;
gv_nSecondLine=0;
gv_nThirdLine=1;
gv_nFourthLine=0;
PORTB.RB6=0;
Delay_ms(100);
}
if(PORTB.RB7)
{
gv_nFirstLine = 0;
gv_nSecondLine=0;
gv_nThirdLine=0;
gv_nFourthLine=1;
PORTB.RB7=0;
Delay_ms(100);
}
INTCON.RBIF=0;
}
INTCON.GIE = 1;
}
void supply()
{
if(gv_nCounter==5)
{
++gv_nInc;
if(gv_nInc==3)
{
PORTA.RA1=0;
PORTA.RA2=0;
PORTA.RA3=1;
gv_nInc=0;
}
if(gv_nInc==2)
{
PORTA.RA1=0;
PORTA.RA2=1;
PORTA.RA3=0;
}
if(gv_nInc==1)
{
PORTA.RA1=1;
PORTA.RA2=0;
PORTA.RA3=0;
}
gv_nCounter=0;
}
}
int verify()
{
if(gc_pPass[0] == gv_pInputPass[0])
{
if(gc_pPass[1] == gv_pInputPass[1])
{
if(gc_pPass[2] == gv_pInputPass[2])
{
return 1;
}
}
}
return 0;
}
void read_input()
{
if(gv_nCursor == 3)
{
gv_nCursor = 0;
}
if(gv_nFirstLine)
{
if(PORTA.RA1==1)
{
gv_pInputPass[gv_nCursor] = '1';
}
if(PORTA.RA2==1)
{
gv_pInputPass[gv_nCursor] = '2';
}
if(PORTA.RA3==1)
{
gv_pInputPass[gv_nCursor] = '3';
}
gv_nFirstLine=0;
gv_nCursor = gv_nCursor+1;
}
if(gv_nSecondLine)
{
if(PORTA.RA1==1)
{
gv_pInputPass[gv_nCursor] = '4';
}
if(PORTA.RA2==1)
{
gv_pInputPass[gv_nCursor] = '5';
}
if(PORTA.RA3==1)
{
gv_pInputPass[gv_nCursor] = '6';
}
gv_nSecondLine=0;
gv_nCursor = gv_nCursor+1;
}
if(gv_nThirdLine)
{
if(PORTA.RA1==1)
{
gv_pInputPass[gv_nCursor] = '7';
}
if(PORTA.RA2==1)
{
gv_pInputPass[gv_nCursor] = '8';
}
if(PORTA.RA3==1)
{
gv_pInputPass[gv_nCursor] = '9';
}
gv_nThirdLine=0;
gv_nCursor = gv_nCursor+1;
}
if(gv_nFourthLine)
{
if(PORTA.RA1==1)
{
gv_pInputPass[0] = '-';
gv_pInputPass[1] = '-';
gv_pInputPass[2] = '-';
PORTD.RD1 = 0;
PORTD.RD2 = 0;
gv_nCursor=0;
}
if(PORTA.RA2==1)
{
gv_pInputPass[gv_nCursor] = '0';
gv_nCursor = gv_nCursor+1;
}
if(PORTA.RA3==1)
{
if(verify()==1)
{
PORTD.RD1 = 1;
PORTD.RD2 = 0;
}
else
{
PORTD.RD1 = 0;
PORTD.RD2 = 1;
}
gv_pInputPass[0] = '-';
gv_pInputPass[1] = '-';
gv_pInputPass[2] = '-';
}
gv_nFourthLine=0;
}
}
void main()
{
int lv_nIter = 0;
int lv_nVerify = 0;
int lv_nSystemLed = 0;
OPTION_REG=0b00000101; // Set prescaler to 64
ANSEL = 0b00000000; // PortA is all digital I/O - no analog input
IOCB = 0b11110000; // Enable interrupt on Port B pins
INTCON.RBIF=0;
INTCON.INTF=0;
INTCON.T0IF=0;
INTCON.RBIE=1; // Enable port B interrut
INTCON.INTE=0;
INTCON.T0IE=1; // Enable TIMER interrupt
INTCON.PEIE=1;
INTCON.GIE=1; // Start interrupting
TMR0 = 99;
TRISD.RD0 = 1;
TRISD.RD1 = 0;
PORTD.RD1 = 0;
TRISD.RD2 = 0;
PORTD.RD2 = 0;
TRISD.RD3 = 0;
PORTD.RD3 = 0;
// Reading pins
TRISB.RB4 = 1;
TRISB.RB5 = 1;
TRISB.RB6 = 1;
TRISB.RB7 = 1;
// Supply pins
TRISA.RA1 = 0;
TRISA.RA2 = 0;
TRISA.RA3 = 0;
TRISA.RA4 = 0;
PORTB.RB4=0;
PORTB.RB5=0;
PORTB.RB6=0;
PORTB.RB7=0;
while(1)
{
supply();
if(PORTD.RD0)
{
read_input();
}
if(gv_nSystemCounter==50)
{
PORTD.RD3 = lv_nSystemLed;
lv_nSystemLed = ~lv_nSystemLed;
gv_nSystemCounter = 0;
}
}
}
I compiled this in mikroC PRO for PIC, and the simulation is made in Proteus 7. If you have any other questions please fell free to write a comment or you can contact me, I will try yo answer as quick as I can.
You can download the code and the simulation from here :
[wpdm_file id=9]
