Mike Clark said:
>
> On Jan 7, 2005, at 2:28 PM, Jim Weirich wrote:
>
>> The firecracker connects to the serial port of the computer and I have
>> tested it against both windows and linux boxes.  I've not heard of
>> anyone
>> who as tried it on a Mac yet (although if you have a Mac, live in the
>> Cincinnati area and would like to test it, I'd be glad to bring my
>> hardware and met with you to give it a try :).
>
> I've tried using several USB-to-serial adapters to connect a
> Firecracker to my Mac, each time with no luck.  I believe the problem
> is due to a timing issue with the Firecracker, though I've never been
> able to confirm it.  Other X10 kits are available for the Mac, of
> course, but the Firecracker specifically seems to be Mac-unfriendly.

Hmmm... The firecracker works by toggling the RTS/DTR signals of the RS272
port.  This signals are NOT the normal signals used for serial data, but
are normally used for handshaking (I think ... my RS232 knowledge is a bit
rusty).  The key is that most serial ports allow software control of those
signals, either through IOCTL calls in Unix or windows systems calls in
Windows.

If the Mac has no native RS232 ports, and uses a USB to Serial bridge, one
must ask:

(1) Does the bridge allow control of the of the RTS/DTR signals,
(2) is that control exerted through the normal IOCTL calls, and
(3) Will the bridge communicate changes in a timely enough fashion to
support the protocol.

If (1) and (2) are true, and (3) is the problem, we could try slowing down
the protocol (it is somewhat self clocking so timing is real critical). 
Slowing down the procotol would be a simple change in the C code extension
in the library.

-- 
-- Jim Weirich     jim / weirichhouse.org    http://onestepback.org
-----------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct,
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)