Spying on a USB connection on Windows?

Question

I have an Arduino application talking over USB to an application on Windows 8 using the MAVLINK protocol. The connection appears as COM3.

Is there a Windows application that can spy on this connection and display the traffic going in both directions? Raw bytes are fine, I don't need the protocol decoded.

Answer 1

You could log serial port activity using Portmon. (Edit: You need to first connect to the local computer via the Computer menu, and you must start capture on the port before a program opens it.)

You may not want to log USB traffic. Such a log would include a lot of extra information relating to the USB to serial adapter which is providing COM3. Portmon would only give you the bytes transferred over COM3, and the Mavlink protocol is entirely contained within that data stream. If you're sure you want to log all USB traffic to and from that device, then I recommend SnoopyPro. In Windows 7, you need to run it as administrator.