[Coco] DW4/Prolific USB/Xubuntu 13.10 Fail [Solved]

[Aaron Wolfe]

On Wed, Jan 8, 2014 at 6:23 PM, Joel Ewy <jcewy at swbell.net> wrote:
> Well, I ordered a couple of the super cheap USB/Serial adapters that Aaron
> says work for him, and got good results with DW4.  If the problem with the
> Prolific chip is a proliferation of bad clones, then perhaps Aaron's source
> has gotten ahold of the real deal.  I couldn't find where Aaron posted the
> link when I looked for it just now, so I'll re-post for any who want to try
> these out:
> http://www.ebay.com/itm/USB-to-RS232-serial-DB9-Adapter-4-XP-Vista-Win7-Female-Screw-FastShipping-USA-/230911838342?pt=US_Parallel_Serial_PS_2_Cables_Adapters&hash=item35c36b0886
>
> I haven't tested them thoroughly yet, or really checked out the performance,
> but the one I opened does seem to work, which is a lot more than I can say
> for the one I had lying around before.
>
> One little hitch I ran into was that when I tried running the configuration
> wizard it wouldn't detect the serial port, and it wouldn't accept the
> /dev/ttyUSB0 (or just ttyUSB0) port if I typed it in manually.  I finally
> decided just to try it anyway, and it worked.  I guess that what was
> happening is that the server was already grabbing the port, which was listed
> in config.xml, so it wasn't available to be discovered or (re-)used by the
> wizard.  Is that a fair guess?

Yes.  DW4 (well, really the RXTX library that DW uses) has a hard time
detecting ports on Linux.  Unlike windows and osx, linux doesn't have
a nifty "hey operating system, what serial ports do you have?"
mechanism.  Instead you have to look around in /dev for likely
suspects, and RXTX does a less than awesome job figuring things out.
It also sometimes struggles to admit ports we are already using do
actually exist.  I think I added some code to try and work around that
at some point, but maybe it isn't effective.

If you're running the wizard for the very first time, it usually works
OK since DW out of the box doesn't try to touch any serial ports.
However, if DW is already using a port, it might not like to 'detect'
it again, especially on Linux.
This definitely is an item on the long list of things I wish were better.

>
> In any case, these particular cheap, no-name USB/Serial adapters from China
> seem to work reasonably well for DriveWire.  At least they're worth the
> pittance you pay for them as a quick and dirty way to add a serial port to a
> computer with only USB.  Now I need to try it out on the Raspberry Pi.
>
> JCE
>
> On 12/25/2013 11:22 PM, Aaron Wolfe wrote:
>>
>> ...
>>
>> Finally, while my experience with prolific adapters has been great, there
>> are plenty of folks who think they are junk.  Maybe some of them are?  If
>> you can connect a to another PC it would be worth confirming you can pass
>> data at 115k or whatever rate you use on the FPGA board.  If it works in
>> minicom or any terminal program, it will very likely work fine with DW.
>>
>> Good luck..
>>
>> On Dec 25, 2013 10:42 PM, "Joel Ewy" <jcewy at swbell.net> wrote:
>>>
>>> I'm trying to get DW4.3.30 working in a somewhat new environment with
>>
>> poor luck...
>> I have one of these USB/Serial thingies.  It's a Prolific -- cheap and
>> sucky, but Aaron says they work for him, right?...
>
>
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