Need tools to communicate with USB device 2

[OnQueIT]

I've been using COMMTOOLS to communicate with serial ports and now I need to move up to USB ports. Are there tools out available for VFP that I can use to replace my old code?

In my control file, the user can select the device name along with port, baud, data bits, stop bits and parity. Not sure if this is important but thought I would add it.

 

[Olaf Doschke]

I never did any device programming on USB, but also used the Commtools to control electronic scales.

USB is a bus in the first place, a bus supporting many very different devices, forget about COM programming, baud, bits,parity etc.

One good starting point for developers is

http://www.usb.org/developers/

and I didn't used this, but it goes in the direction of what you might look for:

http://sourceforge.net/apps/trac/libusb-win32/wiki

What I know from others is, that USB devices like card readers rahter do often enough come with some API dll, SDK or the like, but something proprietary, not as universal as you'd like.

What kind of devices do you have in mind? printers and scanners have much higher level APIs, storage devices of course need no special handling at all.

Bye, Olaf.

 

[OnQueIT]

I have a program to read data from scales but the type and brand of the scale may very and with COMMTOOLS(as you know) you need to know how to communicate with the scale(baud rate, databits, parity, stopbit) and what strings command to send the different scales to request the weight. Since the newer computers do not have serial ports, I am looking for alternatives.

 

[Olaf Doschke]

Well, to use these scales, look for USB to RS232 adapters.

Bye, Olaf.

 

[FoxPro20Years]

As Olaf stated just use USB to Serial adapters, they are cheap, and easy to use. Once installed they create a virtual serial device using the USB.

I use several manufacturers, sewelldirect, radio shack, and others.

$10 - 12 each when ordered in bulk.

 

[OnQueIT]

I've got one from Radio Shack on the shelf and it does work. I just didn't know if there was something else I needed to be using. I appreciate you reminding me to check my closet every now and then. Didn't know about the Sewell brand, I will check this one out also. The ones from radio shack are not the cheapest on the market if you know what I mean.

 

[Olaf Doschke]

We tested a few and had best results with Devices based on FTDI chips, eg FT232R. These were not cheap but compared with the price of precision laboratory scales it's still much cheaper than new scales devices in the range of thousands of Euro.

Bye, Olaf.

 

[TamarGranor]

Just want to add that I had to try three different USB-to-serial adapters before finding one that worked reliably. The one I'm happy with came from KeySpan.

Tamar

 

[gairo50]

Here is a DLL that allows you to read and write to USB ports from any MS language.

http://www.kadtronix.com/usbhidapi_usr.htm

They have a sample application and code but the sample is not in VFP but the DLL it really works.