[Xastir] RE: ref : New, Updated box time - which Linux??

[Jason Winningham]

On Sep 22, 2006, at 6:21 AM, Bennett, Bruce wrote:

> Another choice? Yeah, in the past I have used a PCI serial port card 
> w/4
> ports... $$

Which is fine for a desktop, not so practical for a laptop.  ):  Yeah, 
I know there are PCMCIA solutions, too.

> The SI Labs based devices can actually be re-programmed to bear a 
> unique ID,
> and from that can be made to enumerate in a specific order.

This is all a real weak point in the USB drivers.

The FTDI drivers for Mac OS X claim that, if the device has a serial 
number, the driver will use that serial number as the device special 
file name.  I don't have one that's serial numbered, so I have not been 
able to verify.  The FTDI tools for windows claims to be able to 
serialize a device if it isn't already, but I haven't tried that yet.

> Offhand, I don't know of an OEM branded USB to serial that uses the SI 
> Labs chip -

Not an OEM adapter, but the Sparkfun guys have a breakout board that 
has a USB B connector, the chip, and some headers for TTL level rs232.  
I'm using one now to power and interface a PIC/MX614 packet decoder.

http://www.sparkfun.com/commerce/product_info.php?products_id=198

Looks like SparkFun has also picked up an FTDI device:

http://www.sparkfun.com/commerce/product_info.php?products_id=718

Both those are assembled breakout boards, but they also have the chips 
fairly cheap if an SMT chip solves your problems.

BG Micro (online surplus place) has a device with the FTDI chipset.  
They don't advertise it as such, but I have one and found it to be so.

http://www.bgmicro.com/prodinfo.asp?prodid=COM1193

I've also seen a device using an FTDI chipset that's 100% enclosed in a 
USB A connector, with bare wires on the other end for TTL level rs232 
as well as +5V and ground from the USB port.  I think it was about $15 
a copy, but I can't remember where I found it.


I realize most of these are parts, not packaged solutions, but if 
you're building something from a kit or from scratch, or don't care to 
hack at a piece of equipment, they can make some handy solutions.  My 
favorite part is drawing power from USB, and eliminating both the power 
cord to the peripheral as well as the voltage regulation from the 
circuit.

In my experimenting I have stumbled across one poor solution that works 
for Mac OS X:  Most of those drivers use something vendor specific in 
the device special file name, so if you use only one device from each 
vendor, the names are unique. |:

-Jason
kg4wsv