Adding USB thumb-drive support to existing product
d...@nadler.com
to an existing product. The product has a RS-485
LAN; I'll add a new LAN node that interfaces to
the thumb drive. BOM must be under $30; as always
lower would be better.
To do this requires:
- host USB support
- USB basic software stack
- USB thumb-drive (FAT etc) software stack
- serial port (9-bit capable for our LAN)
I'm considering using a uC we already use plus
the FTDI Vinculum part. Quick development, probably
can meet the BOM (VDRIVE is ~ $25 before qty
discounts, our own board with FTDI controller
would be cheaper).
Anybody got an alternate uC they'd suggest, which
includes all of the above, is available in eval/
devel boards including USB host, has conventional
and robust C development tools, and does not require
$$$ for the software stack and/or tools ? And has
all the required libraries to do file IO to the
thumb drive ?
Thanks in advance for your inputs !
PS: Requirement Notes:
- USB thumb-drive (NOT compact-flash or other storage)
- microcontrollers with proprietary languages
(instead of ANSI C as our existing code requires)
are disqualified (to minimize port work)
larwe
> Anybody got an alternate uC they'd suggest, which
> includes all of the above, is available in eval/
> devel boards including USB host, has conventional
You don't strictly need host, you can use OTG... Look at the Freescale
Flexis parts, specifically the ColdFire-based ones because they
include OTG. It's easy to get started with them because they ship an
eval module which consists of the bare CPU mounted on a tiny PCB with
100 mil headers. The eval board is the DEMOJM board. Although not
explicitly documented, this board can also be used to program your own
boards in-circuit (all you need to do is solder on a 3x2 100mil
header).
The s/w stack (at least for your purposes) is free, provided by CMX,
source is included, development is with regular C in CodeWarrior.
d...@nadler.com
Thanks Lewin, I'll have a look.
Guess I should read up on OTG as well...
larwe
> > The s/w stack (at least for your purposes) is free, provided by CMX,
> > source is included, development is with regular C in CodeWarrior.
>
> Thanks Lewin, I'll have a look.
> Guess I should read up on OTG as well...
I have several spare DEMOJM boards and you are welcome to one if you
want it. It comes with 8-bit and 32-bit target boards; I want the 8-
bit board, but you're welcome to the 32-bit board and the base, which
is everything you need to experiment with the CMX stack. The 8-bit
board won't do OTG anyway. A size-limited version of CW is included.
d...@nadler.com
That's incredibly kind of you, Thanks !
Let me do a bit more research prior I take you up on your offer.
I'll contact you offline...
Again, Thanks !!!
Anton Erasmus
Luminary Micro has a nice dev board that interfaces with a USB
thumb-drive using a USB OTG port. They have a nice dev board
with free tools, libraries etc. to help one get started. Only FAT12
and FAT16 are supported due to licensing issues with Microsoft
on FAT32.
Regards
Anton Erasmus
larwe
> and FAT16 are supported due to licensing issues with Microsoft
> on FAT32.
This is a bit of a phantom. It's generally accepted that if LFN
support is not used, any implementation of FAT32 is compliant. (This
has not TTBOMK been litigated, nor has MS actively pursued a licensing
jihad, since FAT32 is no longer a fashionable FS).
larwe
> That's incredibly kind of you, Thanks !
That's ok - I was at a Freescale seminar where they were giveaways.
After the show I asked for more of the 8-bit target boards to build my
own circuits, and they said "just take a few more entire kits, we
don't have loose target boards". So I did :)
greginfinity
to bootload from a USB key. Not too bad (other than writing the part to
digest the HEX file and write to flash). It is probably going to be an
additional $12 when all said and done in quantity for the project since you
have to purchase the uALFAT and a Maxim part as well. MUCH faster than
writing my own stack, or even using the Microchip one.
d...@nadler.com
uALFAT looks good, but price on their web site is considerably
higher than $12 ???
d...@nadler.com
FAT32 or bust...
OK - I did a bit more homework.
Your comments and thoughts would be appreciated !
FAT16 only supports up to 2GB memory sticks (at least
with "standard" cluster and sector sizes). A 4GB
memory stick now costs $20. Ergo, customers will buy
and plug sticks that require FAT32 into anything we
build now and lives on in the market for a few years.
As these customers know where I live, I think I need
FAT32 support...
So, how to support FAT32 ?
FTDI Vinculum and GHI uALFAT support FAT32.
The GHI uALFAT cost looks like its over our BOM target.
GHI sells a library USB stack plus FAT32 for $3500.
TheFreescale Flexis part suggested by Lewin (MCF51JM64)
is provided with the CMX_lite library, which only supports
FAT16. To get FAT32, we'd need to license the complete
CMX library for $4600 per product, or do something
different.
MicroChip provides a USB-host stack and FAT16 support,
but no FAT32. And their hateful new PIC32 web site
crashes FireFox (I'll need to try again with IE),
though presumably their 16-bitters would be adequate...
Lewin's DOSFS does support FAT32. I had a look and this
looks quite nice, though I didn't find the regression
tests or see how to run them at first glance. I understand
a few minor fixes are pending review and integration;
perhaps I could help here with both. Perhaps I should
layer Lewin's DOSFS on top of the Flexis or Microchip USB
stack.
Your thoughts and komments ?
Thanks in advance,
Best Regards, Dave
larwe
> TheFreescale Flexis part suggested by Lewin (MCF51JM64)
> is provided with the CMX_lite library, which only supports
> FAT16. To get FAT32, we'd need to license the complete
> CMX library for $4600 per product, or do something
> different.
So use the CMX USB stuff and add FAT32 from elsewhere, either mine
(yes I'm late with the fixes) or one of about a zillion other open-
source options, depending on whether GPL is a problem for you or not.
Mike Harrison
Vinculum chip would seem the obvious answer. Even with the socket and supporting parts you're well
under the $30 target if built in. Even the VDIP1 DIP module would just about be in there.
By the way, it can also be a USB slave, so that may save something elsewhere on the BOM.