Portable storage device and method for indicating storage capacity

A storage device comprising:

• a communication unit;
• a main storage unit;
• a capacity indicator configured to indicate a current storage capacity value of the main storage unit;
• a driver configured to drive the capacity indicator to indicate a current storage capacity value of the main storage unit;
• a secondary storage unit storing a preset storage capacity value and a drive table recording relationship between storage capacity difference ranges and rotation angles of the driver, each of the storage capacity difference range values corresponding to one of the rotation angles;
• and
• a processing unit configured to:
• obtain a current storage capacity value from a computer connected to the storage device through the communication unit;
• determine a difference between the obtained storage capacity value and the preset storage capacity value, determine the storage capacity difference range the difference falls within and the rotation angle the determined storage capacity difference range corresponds to in the drive table, and replace the preset storage capacity value with the obtained storage capacity value if the difference is greater than zero;
• and
• control the driver to rotate the determined rotation angle to drive the capacity indicator to indicate the obtained storage capacity value.