#include <avr/io.h>
  #include <stdint.h>

  // leds are connected to port A4..7

  void initLeds() {
    DDRA |= 0xF0;
  }

  void ledOn(uint8_t sel) {
    PORTA |= 1<<(sel+4);
  }

  void ledOff(uint8_t sel) {
    PORTA &= ~(1<<(sel+4));
  }

  void ledToggle(uint8_t sel) {
    PORTA ^= (1<<(sel+4));
  }

  void ledSet(uint8_t val) {
    PORTA = (PORTA & 0x0F) | (val<<4);
  }

  int main() {
    initLeds();
    ledOn(1);
    ledOff(1);
    ledToggle(1);
    ledSet(5);
    return 0;
  }