USB tools you MUST have

From the experience, the developer must have below tools. It would help to debug and clear the issue.

1.USB analysis tool (Ex: CATC)
  It's a public tool for analysis the protocol.
2.The USB catching log software in Windows PC. (Ex: Bus hound)
  It's a necessary tool in debugging with USB device driver.
3.The oscilloscope
  It's a basic tool check the voltage and signal.
4.The power supply + special socket
  It's for USB host driver. Sometimes the pen driver took much power than the VBUS supplying. So it needs to another power supplying for preventing unknown situation.

Special Socket