/**
   * @fn scan
   * @brief Scan all I2C devices connected to the I2C cascade module
   * @param port  Specify the port for scanning
   * @return uint8_t*  Return the I2C address of all devices
   */
  uint8_t *scan(uint8_t port);

  /**
   * @fn selectPort
   * @brief Enable a specific channel on the I2C multiplexer or disable all channels
   * @param port - Select channel, range: 0- 8
   * @n 0-7 for enabling the corresponding channel separately, 8 for disabling all channels 
   * @note When“multiple multiplexer modules” are used on one I2C bus to connect “sensors with same I2C address”, to avoid conflicts,  
   * @n it is necessary to ensure that “the currently used channel”is the only enabled one among “all channels in all multiplexers” 
   * @n For instance, when one of the channels in the first multiplexer is enabled, in order to use any channel in the second multiplexer,  
   * @n please make sure that the channels in the first multiplexer are all disabled.
   */
  void selectPort(uint8_t port);

  /**
   * @fn read
   * @brief  Read the data of the target I2C device 
   * @param port  The I2C port that the target device is connected to
   * @param addr  I2C address of the target device
   * @param reg   Register of the target device to be read
   * @param data  Data of the target device to be stored
   * @param len   Data length of the target device to be read
   * @return uint8_t read status
   */
  uint8_t read(uint8_t port,uint8_t addr,uint8_t reg,uint8_t* data, uint8_t len);

  /**
   * @fn write
   * @brief   Write the data into the target I2C device 
   * @param port   The I2C port that the target device is connected to
   * @param addr   I2C address of the target device
   * @param reg    Register of the target device to be written
   * @param buf    Data of the target device to be written
   * @param len    Data length of the target device to be written
   */
  void write(uint8_t port,uint8_t addr, uint8_t reg,uint8_t* buf, uint8_t len);