Percobaan Keypad 4×4

1. Percobaan Keypad dengan display LED

Pada percobaan ini keypad terhubung ke PORTB dan display ke LED, setiap penekanan tombol pada keypad maka akan ditunjukkan perubahan kondisi pada LED.

#include <mega8535.h>
#include <delay.h>
#include <stdio.h>

// Declare your global variables here
unsigned char dt, dtkey;
void detek_key(void);
void main(void)
{
while (1)
{
// Place your code here
detek_key();
PORTC=dtkey;
delay_ms(5);
};
}

void detek_key(void) {
PORTB.4=0;
dt=(~PINB & 0x0F);
switch (dt)
{
case 1: dtkey=0x1;
break;
case 2: dtkey=0x4;
break;
case 4: dtkey=0x7;
break;
case 8: dtkey=0xa;
break;
};
PORTB.4=1; PORTB.5=0;
dt=(~PINB & 0x0F);
switch (dt) {
case 1: dtkey=0x2;
break;
case 2: dtkey=0x5;
break;
case 4: dtkey=0x8;
break;
case 8: dtkey=0x0;
break;
};
PORTB.5=1; PORTB.6=0;
dt=(~PINB & 0x0F);
switch (dt) {
case 1: dtkey=0x3;
break;
case 2: dtkey=0x6;
break;
case 4: dtkey=0x9;
break;
case 8: dtkey=0xb;
break;
};
PORTB.6=1; PORTD.7=0;
dt=(~PINB & 0x0F);
switch (dt)
{
case 1: dtkey=0xc;
break;
case 2: dtkey=0xd;
break;
case 4: dtkey=0xe;
break;
case 8: dtkey=0xf;
break;
};
PORTB.7=1;
}