[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: usb to serial

On Sun, 4 May 2008, Celejar shared this with us all:
>--} On Sun, 4 May 2008 13:49:24 +1000 (EST)
>--} Daniel Dalton <daniel.dalton@iinet.net.au> wrote:
>--} > I'm a blind debian user and therefore use a braille display.
>--} > So I need to connect it somehow.
>--} > The display is a piece of hardware that is usually connect with a
> serial --} > cable, but since my new box only has a usb available, no
> serial I must use --} > usb to serial.
>--} I have a similar situation with my laptop, which doesn't have 'legacy'
>--} ports such as serial, so I use USB to serial adaptors for my serial
>--} equipment.
>--} > So does anyone know of the following:
>--} >
>--} > - a supported usb to serial cable for linux that works with the
> kernel? --}
>--} These adaptors are 'smart', i.e. they contain electronics to do the
>--} conversion, so as with hardware generally with linux, what counts is
>--} the chipset.  I believe that many of these devices use the Prolific
>--} PL2303 chipset, which shows up with 'lsusb', at least in my case, as
>--} "ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port".  This
>--} chipset has kernel support via the pl2303 driver.  I have another
>--} adaptor whose ID apparently isn't in the database; nothing shows up
>--} other than the numerical ID.  It is also grabbed by pl2303 (although
>--} IIANM, that wasn't the case several months ago, when I first acquired
>--} it), but it doesn't seem to be working properly, as opposed to the
>--} Prolific one, which works fine.
>--} I purchased both my adaptors on Ebay.  They are virtually identical in
>--} appearance, except for color; both have attractive silver cables
>--} sheathed in clear plastic, but the Prolific has black plastic covering
>--} the two cable ends (serial and USB), while the other has translucent
>--} green.  This may not help you.
>--} I originally bought these adaptors to use with serial modems, but I was
>--} never able to get them to work properly, and I never figured out why.
>--} I'm currently using the Prolific to manage a headless box via a serial
>--} (null modem) cable, and it works perfectly.  The other one is not
>--} working properly, as above.
>--} These things start at about $5 (USD), including shipping (to the USA)
>--} on Ebay.  If you search there for 'usb serial', the first bunch of hits
>--} seem to be the sort of units that I bought.  There are both green
>--} headed ones, as well as black headed ones, but I don't know if the
>--} color is a reliable indicator of the chipset.
>--} > (If so could you please provide a model number or brand?) Or even
> better --} > if you know where I can get one of these from?
>--} > Perhaps you could show me an add on ebay?
>--} > (I had a look, but don't really understand the info and I am having
>--} > trouble using my computer obviously.)
>--} > - If the kernel supports it will a software daemon (brltty) support
> it? --}
>--} I don't know brltty, but I'd say almost certainly yes.  I'm no kernel /
>--} hardware expert, but basically, the kernel driver creates a virtual
>--} serial port, which should appear identical to an actual one to
>--} userspace.
>--} Good luck!
>--} > Daniel Dalton
>--} Celejar

I have used a USB to RS232 Cable for some years with Linux Debian, coupled to 
an external dialup modem and it worked a treat without fault. It was not a 
fancy brand named cable, just one that I picked up in a computer shop, and 
was about 1 metre long I think? I haven't used it with testing for about 3 
months because I now use satellite. So something may have changed since then?

Registered Linux User:- 329524
The lesson which life repeats and constantly enforces is "look under foot." 
You are always nearer the divine and the true sources of your power than you 
think. The lure of the distant and the difficult is deceptive. The great 
opportunity is where you are. Do not despise your own place and hour. Every 
place is under the stars, every place is the center of the world. ----JOHN 

Debian, just the best way to create magic

Reply to: