How do you measure the voltages in an external usb device, such as a usb missile launcher?

[Cuchulain]

Any Suggestions?

[smercurio_fc]

Well, you'll need some hardware to measure voltages, such as a multimeter or a data acquisition device, such as the USB-6008. What are you trying to do with these measurements? And what are you shooting at?

[Cuchulain]

I'm trying to control the missile laucher with labview.  I was going to try to look at the voltages going to it so that I could figure out how much voltage I would have to send to the motors in the toy so that I could control them.

[smercurio_fc]

So you're really dealing with your original thread. Please stick to the original thread.

[ajmartin]

USB is a funny thing. Typically 5V max provided by the client PC. A lot of devices use 3.3V , The current the USB device will use is determined during enumeration. And the client device negotiates this with the PC. As was stated in the duplicate post you made a few days ago, Your missile launcher will need either LV drivers provided by the manufacture or a DLL file OR some way of knowing the communication protocol of the missile launcher.

Alan

[smercurio_fc]

Corrected link for original thread: http://forums.ni.com/t5/LabVIEW/How-do-I-control-the-motors-in-a-third-party-usb-toy-with/m-p/131306...