USB communication

[MarHilMen]

Hello,

Nice that you get help here when things get tight, you are try new things ... The USB port is a little ... difficult to use, I think you operate the port via the VISA function panel ... but does anyone have a few short, executable program snippets  that he might make available to the public here? A few auxiliary routines would also be helpful ... Which ports are currently occupied, information about the ports so that the user can then select a port, etc. ...... does anyone have what?

And how can it be that everyone has 10 USB devices ... and more .. but you can find so little about the programming of the USB interface? 😉

[gdargaud]

You should first try and use USB devices through their provided drivers. If there aren't any drivers, which happens if it's custom hardware, then, yes, you can use VISA. Otherwise it's overkill and mostly impossible if you don't have the specs.

[MarHilMen]

I am trying to communicate with an I2C "converter"

via USB because I want to try different methods to

connect an I2C to the PC.
With the help of the forum (LabJack) I have been able

to operate an 8574 via CVI and Labjack U6, next I will

test the 23017.

Here, in this case, I'm trying to use a FTDI FT232H from FTDI

(also with the 8574 on the I2C bus), which I haven't been able

to do so far ... The VISA functionalities were so far the only thing

I found. If there is one there would be an easier way to access

the USB port via CVI, that would of course be very nice and let me know 😉

[mjl]

Usually FTDI has drivers that work like virtual com ports.  Do you see a new COM port in device manager when you plug it in?  If so you can access it using serial communication commands.

[BigApple0]

You're going down the wrong path if you're trying to use raw USB drivers with FTDI chips.  Use the drivers provided by FTDI.

You have a couple options depending on which interface of the FTDI device you want to use.

If its the serial UART interface then use the VCP driver from FTDI.  The chip appears as a standard Windows COM port.

If you're communicating over I2C you can use the D2XX driver to interface with the MPSSE or they provide a simplified wrapper driver called LibMPSSE-I2C.  Its a simplified wrapper over the D2XX driver.

[MarHilMen]

Thank You very much,

I will try this!