#include <stdint.h>
#define DDRA (*(volatile uint8_t*)0x21) //led
#define PORTA (*(volatile uint8_t*)0x22) //output
#define DDRb (*(volatile uint8_t*)0x24) //led
#define PORTb (*(volatile uint8_t*)0x25) //output
#define DDRF (*(volatile uint8_t*)0x30) //keypad
#define PORTF (*(volatile uint8_t*)0x31) //output
#define DDRK (*(volatile uint8_t*)0x107) //leypad
#define PORTK (*(volatile uint8_t*)0x106) //input
uint8_t i,j;
void setup() {
DDRF = 0XFF;
DDRK = 0X00;
DDRA = 0XFF;
}
void loop() {
for(i=0; i<4; i++){
PORTF = (1<<i); //Port f matrix row giving supplu port k is reading pin
PORTA = PORTK; //port a is led connected pin
if(PORTK != 0){
PORTb = (1<<i); //for display ing row
PORTb = 0;
}
}
}