[BRLTTY] Re: [Bug 84139] Re: Arduino detected as braille device

[Mario Lang]

Samuel Thibault <samuel.thibault at ens-lyon.org> writes:

> Hi,
>
> Colin Watson, le Fri 09 Feb 2007 09:18:12 -0000, a écrit :
>> # HandyTech
>> SYSFS{idVendor}=="0921", SYSFS{idProduct}=="1200", RUN+="/lib/brltty/brltty.sh -b ht -d usb:"
>> SYSFS{idVendor}=="0403", SYSFS{idProduct}=="6001", RUN+="/lib/brltty/brltty.sh -b ht -d usb:"
>> 
>> These come from Debian.
>
> Ah oops, indeed, I overlooked that. It's in the brltty repository too,
> so I'm Ccing the mailing list: a Ubuntu user just wanted to plug a
> special USB adapter (not related to braille at all), and brltty got
> started, because the ID of his adapter is
>
> Bus 002 Device 005: ID 0403:6001 Future Technology Devices International, Ltd 8-bit FIFO
>
>> "8-bit FIFO". What's one of those? Sounds like maybe a generic bit of
>> electronics that sometimes happens to have a Braille terminal attached?
>
> Possibly. Does anybody on the brltty list have more information on this?

The FTDI chip is used in Handy Tech Braille displays to implement
the USB connectivity.  What they basically did is put this chip
on top of their already existing serial interface, therefore avoided
having to implement their own USB stack/protocol, they simply
reuse an existing USB->Serial adaptor chip, and drivers talk with the
display with the exact same byte-protocol either via serial, USB or bluetooth.

FYI, here is how my Handy Tech Modular Evolution 88 identifies:

Bus 001 Device 041: ID 0403:6001 Future Technology Devices International, Ltd 8-bit FIFO
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               1.10
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0         8
  idVendor           0x0403 Future Technology Devices International, Ltd
  idProduct          0x6001 8-bit FIFO
  bcdDevice            4.00
  iManufacturer           1 FTDI
  iProduct                2 USB <-> Serial
  iSerial                 0
  bNumConfigurations      1
...
(the rest is standard USB->Serial adaptor config description...)

P.S.: I own (and use) devices of both types mentioned in this bug, the
PID 6001 and the PID 1200 (which is very rare indeed). Feel free
to contact me with more questions.
-- 
CYa,
  Mario | Debian Developer <URL:http://debian.org/>
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-- 
Arduino detected as braille device
https://launchpad.net/bugs/84139