> There was discussion on here a few weeks ago about that Vinculum
> chip. Mostly people praising the appropriate god there was a host
> controller available from FTDI...

Thanks Shawn. Having looked that thread up I now remember the
other chips mentioned and had looked at a couple independently. I
hadn't remembered the Vinculum

> Without knowing what the primary use of the USB port is, can you
> not add both functions via the same chip?  I thought the 18F4550 was
> capable of that (but then I was just glancing through the DS)

I think all micros are peripheral only. That's why host controllers are
now starting to appear for embedded applications
 
> I don't imagine you can bit bang USB just because of the speeds
> required. Even if you had the speed, I would not recommend it.  The
> timing is very tight

Can't say I'm too keen on that idea anyway. If there's a chip to do it
via UART or SPI, I'd go for it

> Could add a second 4550 to your board...?  If you're already
> connected to the PC, then why not use it to send the data to the
> flash drive for logging?

Datalogging is for a unit that stays out in the field. Data will be
transported in a pluggable memory device

I've taken a look at Microchip's AN1003, which describes i/f with
a memory card, rather than a flash drive. That would probably do
for a one-off or different application, but the intention is to go
commercial, and I think USB devices are more common than flash
cards. Besides, the client has specified USB so that's what I'll be
doing

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