Nugget: 1 of n : GEtting started with USB communication via VISA

[Intaris]

 
Please don't post multiple times with the same question (this is the second time I've come accross this exact question).  It gets people annoyed.

Read the thread you have just posted in and if that doesn't help, then read the USB standard available at www.usb.org.

Shane.

[amitgahoi143@gmail.com]

hello Shane,

I am using PIC18F14K50 installed usb. i am trying to communicate with the help of a labview. I am successful in reading the device but i am unable to write to the device. I am using PIC 18F14K50 as a mouse in a circle demo. Please can anybody throw a light how to perform control out function in Usb raw control communication.vi . I have read the usb specifiaction and HID specifiaction as told by you and read over the nugget part 1 & part 2 but i can only perform control In function and not control out function. When I put request (7) ,request type (0),value (100) ,Index (0 ), Length (12) for getting set descriptor value i got an error message ( ERROR : 1073807240) which states that VISA: ( Hex 0* BFFF0078) the value of some parameter ( which parameter is not known) is invalid. I know this a bit annoying and frustating to ask the same question but i will be more than happy if u can help me in this regard.The nugget 1 & nugget 2 both are excellent blog describing a usb raw communication.

[Standardnutzer]

Hi Intaris,

I just tried to follow your example in the beginning of this thread.

When assigning the freshly created driver to a pc-mouse or a joystick Windows wouldn't accept it.

If I use other USB devices (non HID) the assignment of a RAW driver created with the Driver Wizard works fine.

Is there something else to consider when dealing with devices originally marked as HID?

Uli

[Intaris]

Uli,

which OS are you using.  All of my work was done on XP.  I don't have a single VISTA license and I haven't bought a Windows 7 licence yet.

I know that the Mac claims a HID for itself and no access is possible without writing a custom driver for it.  Perhaps Vista or Win7 does the same?

Shane.

[Standardnutzer]

Shane,

thanks for the fast respond.

That's the strange thing about it: I am using an ordinary Windows XP 32 Bit (Service Pack 3)

Uli

[Intaris]

The VISA driver is unsigned, could this be a problem?

Depending on your security settings, XP may or may not allow installation of unsigned driver packages.

Shane.

[Standardnutzer]

Shane, it must be something else since the procedure works for e.g. a USB to RS232 converter but it won't work for either mouse or joystick. To me it looks like a HID issue....

[Intaris]

Wierd.  It worked fine for me.  I used different Joysticks and mice (and keyboards) for testing and it worked fine for me.

Did you disconnect the device and re-connect after installing the driver?

Have you tried changing the dirver manually in the device manager while the HIDs are connected? 

Shane.

[Standardnutzer]

Yes, I did. Windows allows my VISA made driver for a non HID device but not for HID devices.

[Intaris]

And if you click on "Datenträger" and select the driver file manually?  Does that work?

I never really pay much attention to the "compatible Hardware" because it mostly has duplicate names on my machine.  I always prefer to directly select the driver file directly each time.

Otherwise I'll try it our this evening and report my findings.

Shane.