//Salman Taş 20191701044
void setup() {
    asm volatile (
        ".equ DDRB, 0x04                         \n"
        ".equ PORTB, 0x05                        \n" // set as output

        ".equ DDRD, 0x0A                         \n" 
        ".equ PIND, 0x09                         \n" // set as input

      "mainProgram:                   \n"    // Main program
      "     in r21, PIND              \n"    // read from PIND to r21
      "     cpi r21, 0b11110000       \n"    // compare r21 with 11110000
      "     breq yellow               \n"    // Branch if Equal to yellow
      "     brlo red                  \n"    // Branch if Lower to red 
      "     brsh green                \n"    // Branch if Same or Higher to green
      "     jmp mainProgram           \n"    //(no need for this line; just to make sure)

    "yellow: \n"                          // yellow
      "     cbi PORTB, 0              \n"  // off pin 0
      "     sbi PORTB, 1              \n"  // on pin 1
      "     cbi PORTB, 2              \n"  // off pin 2
      "     jmp mainProgram           \n"  // Jump to mainProgram

    "red: \n"                             // red
      "     cbi PORTB, 0              \n"  // off pin 0
      "     cbi PORTB, 1              \n"  // off pin 1
      "     sbi PORTB, 2              \n"  // on pin 2
      "     jmp mainProgram           \n"  // Jump to mainProgram

    "green: \n"         // green || since breq is before brsh I don't need additional check here
      "     sbi PORTB, 0              \n"  // on pin 0
      "     cbi PORTB, 1              \n"  // off pin 1
      "     cbi PORTB, 2              \n"  // off pin 2
      "     jmp mainProgram           \n"  // Jump to mainProgram
    );
}

void loop() {

}

// pin 0 and 1 resposible for serial connection, so they are throwing random chars. 
// but circuit works ok