STM32 HAL 如何在switch case 语句中使用长的字符串作为条件如：“case01”这样的组合

使用CubeIDE 运行下面部分代码报错：multi-character character constant [-Wmultichar]

      if(HAL_UART_Receive(&huart1,Rxbuf,sizeof(Rxbuf),1000)==HAL_OK)
      {
        int data = Rxbuf[4];
        switch(data)
          {
          case 's1':
              STEPPER_CONTROL(2,1600,1);
              printf("case1\n");
              break;
          case 's2':
              STEPPER_CONTROL(1,3200,1);
              printf("case2\n");
              break;
          case 's2':
              STEPPER_CONTROL(3,6400,0);
              break;
              printf("case1\n");
          default :printf("Unknow Command\r\n");

          }
      }
  }
  /* USER