Re: [Pyusb-users] Mapping usb serial devices to device filenames

[Brendan S. (eTRIX) <Bre...@eT...>]

Thanks Santiago :)
Unfortunately I'm new to usb so it's not making too much sense at the
moment.

What is the class object that self is referring to here ?

Is getdevs() your own function or a standard os function ?
Presumably getdevs calls something like usb.busses() somewhere ?

I don't see how this gives me the name of the serial device (eg.
/dev/cu.usbmodem0001) that I can then reference with pyserial Serial()
function.
example:
    port = '/dev/cu.usbmodem0001'  # need to auto detect/determine this
    ser = serial.Serial( port )

Thanks Brendan.


Santiago Palomino Sanchez-Manjavacas wrote:
> Well, you can use the device VID and PID to select which device to open.
> I use something like:
> 
>    def do_d(self, args):
>         if self.devh is not None:
>         self.do_close('')
> #ls
>     if self.devh is None:
>         self.devs=getdevs()
>     shortlist(self.devs)
>         dn = -1;
>         index = 0;
>         for d in self.devs:
>                 if (d[1].idVendor == 0xFFFF and d[1].idProduct == 0x0000):
>                         dn = index;
>                 index = index + 1;
>         if(dn == -1):
>                 return 1
>     self.curdev=self.devs[dn]
>     self.devh=self.curdev[1].open()
>     self.devn=dn
>     self.devh.setConfiguration(self.curdev[2])
> 
>     self.devh.claimInterface(self.curdev[2].interfaces[0][0])
>     self.devh.setAltInterface(0)
> 
> 
> 
> On Wed, Jun 17, 2009 at 7:14 AM, Brendan Simon (eTRIX)
> <Bre...@et... <mailto:Bre...@et...>> wrote:
> 
>     I have a device with a usb connection that presents itself as a serial
>     device to operating system (OS X).
>     It appears as /dev/cu.usbmodem0001 and /dev/tty.usbmodem0001 on the
>     filesystem when the device is plugged in.
> 
>     I can successfully detect the device USB Vendor ID and Product ID using
>     pyusb :)
> 
>     Now I have to use pyserial to talk to the device -- which I have
>     successfully done by opening the serial port with a hard coded device
>     filename (/dev/cu.usbmodem0001).
> 
>     There must be some way for me to use the pyusb information to be able to
>     determine the appropriate device filename to open with pyusb.
> 
>     Does anyone know how to do this or have any suggestions ???
> 
>     Thanks, Brendan.