Bafo BF-810 USB2SERIAL converter (DB9) with Panasonic GD76 cell phone

author: Giuseppe Rota  morpheus.bs **at** libero.it

This document describes how to use the Bafo BF-810 usb-to-serial converter under linux with a GD76 cell phone, in order to estabilish a GPRS connection.
My brother has a Evo N1015V laptop. That model lacks of a db9 serial port. My brothers also owns a GD76 cell phone which requires a DB9 serial port in order to estabilish a GPRS connection via its data cable as explained in this document.
We found in our local store a usb2serial converter from Bafo Inc. shipped with Windows only driver.
I fought hard to make it work under linux, and eventually did it. But it's very simple indeed.
First of all let's say that the converter uses (or anyway is compatible with) the Profilic PL2303 module of the kernel.
I don't know why, maybe Bafo and Profilic use the same chip for the protocols conversion...
So, we only need to have a pl2303 module for our kernel.
Another option is obviously to have a monolitich kernel with the pl2303.o code inside itself.
I won't discuss here how to obtain this situation. Read the Kernel Howto, or others related Howtos, like Modules Howto.
RedHat 9.0, for example, is shipped with a very modular kernel, including the Profilic PL2303 module, so, if that's the case we don't need to compile anything.
I will assume from now that the kernel has the possibility to access the pl2303 code from inside itself or outside as a module.

Anyway, link your cell with your panasonic data cable. Then link your DB9 Male data cable output with the Bafo converter. Then, without rebooting your machine, plug the usb port into your pc. You should see some messages from the kernel like these:

Sep 13 16:17:33 nethunsiel kernel: hub.c: new USB device 00:10.2-2, assigned address 2
Sep 13 16:17:33 nethunsiel kernel: usb.c: USB device 2 (vend/prod 0x67b/0x2303) is not claimed by any active driver.
Sep 13 16:17:36 nethunsiel /etc/hotplug/usb.agent: Setup pl2303 for USB product 67b/2303/202
Sep 13 16:17:36 nethunsiel kernel: usb.c: registered new driver serial
Sep 13 16:17:36 nethunsiel kernel: usbserial.c: USB Serial support registered for Generic
Sep 13 16:17:36 nethunsiel kernel: usbserial.c: USB Serial Driver core v1.4
Sep 13 16:17:36 nethunsiel kernel: usbserial.c: USB Serial support registered for PL-2303
Sep 13 16:17:36 nethunsiel kernel: usbserial.c: PL-2303 converter detected
Sep 13 16:17:36 nethunsiel kernel: usbserial.c: PL-2303 converter now attached to ttyUSB0 (or usb/tts/0 for devfs)
Sep 13 16:17:36 nethunsiel kernel: pl2303.c: Prolific PL2303 USB to serial adaptor driver v0.9

The important line is that where the kernel informs us of the converter attached to ttyUSB0.
If that's achieved, you can try to run this command, assuming that you've created the pppd script as explained here

pppd ttyUSB0 115200 file ~/xpppd


KPPP

Well,  now, assuming that we have done everything explained here and that our /dev/modem is a symlink, let's do (as root) :

ls -l /dev/modem
(is it a symlink??!)
(if it's a symlink type what's below to overwrite it)
ln -sf /dev/ttyUSB0 /dev/modem

We do that because Kppp hasn't in its scrol-list the possibility to choose /dev/ttyUSB0.
Ok, now check if the minterm of kppp (Options -> Modem -> terminal)  outputs:
AT
OK
If that's the case we've done it. you can use kppp. (once again, if you did what was explained here)
If  we see only OK, or even nothing at all, try to switch off and then again on the cell phone or sending him an ATZ, and retry.

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