How to communicate via USB "port"

[robinp.la]

Can someone explain how I would read the data from the USB "port"? I
don't know if it matters, but I am trying to read the data from a GPS
plugged in to the USB port.

Thank you,
Robin

[Paul McGuire]

On Apr 18, 12:54 am, "[e-mail]" <[e-mail]>
wrote:

Can someone explain how I would read the data from the USB "port"? I
don't know if it matters, but I am trying to read the data from a GPS
plugged in to the USB port.

Thank you,
Robin

Just a guess, but can you use pyserial to talk to USB001?

-- Paul

[Grant Edwards]

On 2007-04-18, ro*******@gmail.com <ro*******@gmail.comwrote:

Can someone explain how I would read the data from the USB "port"?

You can't. There's no such thing from a SW point of view. ;)

I don't know if it matters, but I am trying to read the data
from a GPS plugged in to the USB port.

It's probably a serial device. Try using pyserial to talk to
/dev/ttyUSB0.

--
Grant Edwards grante Yow! Used staples are good
at with SOY SAUCE!
visi.com

[jkn]

Have a look for PyUSB - there are (confusingly) two different packages
called pyUSB. one interfaces to FTDI chips connected to a USB port:

http://bleyer.org/pyusb/

The other uses libusb to interface to devices generally under windows:

http://pyusb.berlios.de/
HTH
jon N

[Tim Roberts]

"ro*******@gmail.com" <ro*******@gmail.comwrote:

>
Can someone explain how I would read the data from the USB "port"? I
don't know if it matters, but I am trying to read the data from a GPS
plugged in to the USB port.

USB is a "protocol" bus. It isn't like a serial port, where you can just
start reading bits. Each device has one or more "interfaces", and each
interface has one or more "pipe" for transmitting data. You have to know
which "pipe" to talk to, what kind of pipe it is, and how to force the
device to send before you can talk to it.

On the other hand, as someone else pointed out, many types of USB devices
fall into standard device classes, and the operating system supplies
drivers for those classes. If your GPS device is in the communication
class, you might be able to pretend it is a serial device.
--
Tim Roberts, ti**@probo.com
Providenza & Boekelheide, Inc.