void TIM3_IRQHandler() {
    char key = key_scan();
    char input;
    if (phase == 0) {
        char result = getchar_irq();
      if (my_turn == 'Y') {
        if (key != '\0') {
            putchar_irq('Y');
            pc12out();
            my_turn = 'N';
        }
      }
        if (result == 'Y') {
            my_turn = 'Y';
        }
    }
    //printf("Hello");
    if (phase == 1) {
        phase1(key);
    }
    else if (phase == 2) {
        if (key != '\0') {
            phase2(key);
        }
    }
    else if (phase == 3) {
        if (opponent_ready == 'Y') {
            if (my_turn == 'Y') {
                if (key != '\0')
                    phase3_attack(key);
            }
            else if (my_turn == 'N') {
             //  printf("hello" );
             /*  while(counter < 4) {
                   printf("hello2" );
                if((USART1->ISR & USART_ISR_RXNE) == USART_ISR_RXNE) {
                    insert_echo_char(USART1->RDR & 0xff);
                    counter++;
                }
               } */
              // if (counter == 4) {
                   //printf("Hello1");
                //insert_echo_char(USART1->RDR & 0xff);
                input = getchar_irq();
               // putchar_irq(input);
                if ((input) >= 48 && (input)  <= 57) {
                    //putchar_irq(input);
                    if (count < 2) {
                        X[count] = input;
                    }
                    else {
                        Y[count-2] = input;
                    }
                    count++;

            X[2] = '\0';
            Y[2] = '\0';
            //printf("%c",X[0]);
           // printf("%c",X[1]);
            counter = 0;
            if (count >= 4) {
                int X_coordinates = atoi(X);
                int Y_coordinates = atoi(Y);
                printf("%d",X_coordinates);
                  printf("%d",Y_coordinates);
            if (ships[X_coordinates][Y_coordinates] == 1) {
                putchar_irq('H');
                ships[X_coordinates][Y_coordinates] = 0;
                opp_hit++;
            }
            else {
                putchar_irq('M');
            }
            count = count % 4;
            if (opp_hit == 17) {
                           phase = 4;
                       }
                       my_turn = 'Y';
          }


                // if RECEIVED coordinates
                //      TRANSMIT HIT OR MISS (Did opponent hit or miss)
                //      if HIT
                //          opp_hit++;
                //      UPDATE "your" screen

            }
            }
        //}
        }
    }
    else {
        if (win == 'Y') {
        //      DISPLAY WIN
        }
        else {
        //      DISPLAY LOSE
        }
    }

    ack_tim3();
}