In article <fvkj8p$cqn$1@aioe.org>, ulf@a-t-m-e-l.com says...
> "www.interfacebus.com" <Interfacebus.Engineer@gmail.com> skrev i meddelandet 
> news:c6648f12-e2c5-453a-9c84-cbd7d8de4fbe@k37g2000hsf.googlegroups.com...
> On May 1, 7:00 pm, mach7 <mach7so...@gmail.com> wrote:
> > I know very little about USB, so excuse the naive question. I'm
> > looking for an IC that I can interface with a microcontroller (in my
> > case, the ATMega32) that will let me communicate with a computer over
> > USB. My project involves large data transfers (for logging purposes)
> > and serial / UART is too slow. Any direction would be helpful.
> >
> > Thanks,
> > -J
> 
> 
> The AT90USBxxx chips will allow you to do
> a bulk transfer, which seems to be more inline
> with your needs than a USB<->Serial chip.
> 
> 
The FTDI chips also use the bulk transfer mode.  It makes
the most sense for any device where you want high
data rates with intermittent transfers and guaranteed
end-to-end delivery.


Mark Borgerson

"www.interfacebus.com" <Interfacebus.Engineer@gmail.com> skrev i meddelandet 
news:c6648f12-e2c5-453a-9c84-cbd7d8de4fbe@k37g2000hsf.googlegroups.com...
On May 1, 7:00 pm, mach7 <mach7so...@gmail.com> wrote:
> I know very little about USB, so excuse the naive question. I'm
> looking for an IC that I can interface with a microcontroller (in my
> case, the ATMega32) that will let me communicate with a computer over
> USB. My project involves large data transfers (for logging purposes)
> and serial / UART is too slow. Any direction would be helpful.
>
> Thanks,
> -J


The AT90USBxxx chips will allow you to do
a bulk transfer, which seems to be more inline
with your needs than a USB<->Serial chip.

-- 
Best Regards,
Ulf Samuelsson
This is intended to be my personal opinion which may,
or may not be shared by my employer Atmel Nordic AB

John Devereux <jdREMOVE@THISdevereux.me.uk> wrote

>> So G., what is a better solution than FTDI?
>> And why?
>>
>> Frank
>
>I would like to know this too. Also, are there any can be used without
>supplying a driver (with recent versions of windows perhaps)?

I've sold thousands of FTDI based USB-422/485 converters and had no
problem at all in the field. I think that's pretty good.

There is a downside to having chosen the 'unique device' option (a
serialised eeprom), which is that if you want to connect several of
the devices to the same PC (actually this may be a very unusual
scenario but one of my customers likes to do it) then windoze thinks
it's a different device each time and forces you to install the driver
for each device. Not a big deal (copy the installation CD into a temp
dir and install from that; then you don't need to carry the CD about)
and apparently there is no solution under windoze.

We've had some weird support issues with the Prolific product (again
sold thousands of them) which were related to the known behaviour of
getting a new COM port every time you plug a NON serialised USB device
into a different USB port on the same PC. In one case I recall,
windoze created a new COM port # every time the device was plugged
into the *same* USB port. But to be fair this is very rare.

Nearly every USB-serial adapter on the high street is made in China
and uses the Prolific chip.

On May 1, 7:00=A0pm, mach7 <mach7so...@gmail.com> wrote:
> I know very little about USB, so excuse the naive question. =A0I'm
> looking for an IC that I can interface with a microcontroller (in my
> case, the ATMega32) that will let me communicate with a computer over
> USB. =A0My project involves large data transfers (for logging purposes)
> and serial / UART is too slow. =A0Any direction would be helpful.
>
> Thanks,
> -J

There are a number of USB ICs listed here;

http://www.interfacebus.com/Design_Connector_USB.html

On May 2, 9:45 am, "FD" <f...@fd.ods.org> wrote:
> <ghel...@lycos.com> schreef in berichtnews:8b206752-b181-448d-9cca-0fb6203c9edc@y22g2000prd.googlegroups.com...
>
>
>
> > On May 1, 11:03 pm, Peter <nos...@nospam9876.com> wrote:
> >> mach7 <mach7so...@gmail.com> wrote
>
> >> >I know very little about USB, so excuse the naive question.  I'm
> >> >looking for an IC that I can interface with a microcontroller (in my
> >> >case, the ATMega32) that will let me communicate with a computer over
> >> >USB.  My project involves large data transfers (for logging purposes)
> >> >and serial / UART is too slow.  Any direction would be helpful.
>
> >> >Thanks,
> >> >-J
>
> >> There are two major chips which implement a USB slave i.e. a way to
> >> talk to a PC which has a USB port (a USB controller).
>
> >> One is Prolific in China, the other is FTDI in the UK.
>
> >> Prolific are absolutely crap on support - I sell a product with their
> >> chip in and we never get any backup. Even buying them is a process...
> >> But it works OK. It is cheaper of the two in volume.
>
> >> FTDI is much better (www.ftdichip.com) and they have good support.
> >> price is about USD 2.50 in 1k quantities. Look up the FT232 or similar
> >> - this gives a serial interface which you can connect to your
> >> microcontroller's serial port directly.
>
> >> Both chips come with free drivers which create a virtual COM port
> >> (VCP) within the operating system. FTDI do much more driver support
> >> including various kinds of unix.
>
> >> I sell a product with the FT232 in it and we are very pleased with it.
> >> We use the Prolific chip only because the product that uses it is made
> >> wholly in China so we have no choice.
>
> >> There is a huge amount of work in the development of bug-free PC VCP
> >> drivers. You would never want to write your own. Windows implements
> >> predefined USB drivers for a few things like a USB keyboard/mouse,
> >> parallel port, but curiously not a serial port which is why if you
> >> want a USB serial port you have to provide the user with the VCP
> >> drivers.
>
> >> One thing to consider is that the way windoze enumerates USB devices,
> >> it creates a new COM port # every time you plug the *same* device into
> >> a new USB port on the *same* PC. This is a right pain. The solution is
> >> to put an EEPROM in your product and write a unique serial number into
> >> this, and then the COM port becomes fixed to the device itself which
> >> is generally much more helpful. Very few USB product manufacturers
> >> bother with this EEPROM however. We do it on the FTDI chip based
> >> product - it's very easy. FTDI provide a different set of drivers (not
> >> VCP) which you install on a PC used to serialise your product and
> >> these provide access to the EEPROM. You just write in a string which
> >> contains a hash of today's date/time or whatever and then every one is
> >> unique.
>
> > I would NOT recommend FTDI.  Their software is poorly documented, and
> > very buggy.
>
> > Worst part is that when you point this out they respond with attitude
> > rather than assistance.
>
> > There are many, many other vendors to choose from.
>
> > G.
>
> I am in the process of selecting a USB to serial converter.
>
> So G., what is a better solution than FTDI?
> And why?
>
> Frank

TI and SiLabs are two.  Right now I'm so frustrated with FTDI's
technical support that I'm tempted to say "any".

I too have had trouble with the Prolific adapter.  There are some
standard function calls that their driver does not support, but it
always returns a "success" status code.

G.

On Fri, 2 May 2008 18:45:43 +0200, "FD" <fd@fd.ods.org> wrote:

><ghelbig@lycos.com> schreef in bericht 

>> I would NOT recommend FTDI.  Their software is poorly documented, and
>> very buggy.
>>
>> Worst part is that when you point this out they respond with attitude
>> rather than assistance.
>>
>> There are many, many other vendors to choose from.
>>
>> G.
>
>I am in the process of selecting a USB to serial converter.
>
>So G., what is a better solution than FTDI?
>And why?

For one data point: The original data cable for Fluke's 190-series
Scopemeters used a Prolific chip as the USB/serial gateway. The
provided drivers would hang during data transfers on PCs with dual
core CPUs. There was no in-place fix (no new drivers or firmware);
Fluke had to make a new USB/serial cable using FTDI chips -- which
work fine.

Some discussion of this at
<http://www.flukecommunity.com/forums/showthread.php?t=553>

I never did pop open the connector on the Rev 1 (Prolific) cable
(it's on the "someday" pile) but the Rev 2 (FTDI) has been completely
reliable.

-- 
Rich Webb     Norfolk, VA

"FD" <fd@fd.ods.org> writes:

> <ghelbig@lycos.com> schreef in bericht 
> news:8b206752-b181-448d-9cca-0fb6203c9edc@y22g2000prd.googlegroups.com...

[...]

>>
>> I would NOT recommend FTDI.  Their software is poorly documented, and
>> very buggy.
>>
>> Worst part is that when you point this out they respond with attitude
>> rather than assistance.
>>
>> There are many, many other vendors to choose from.
>>
>> G.
>
> I am in the process of selecting a USB to serial converter.
>
> So G., what is a better solution than FTDI?
> And why?
>
> Frank

I would like to know this too. Also, are there any can be used without
supplying a driver (with recent versions of windows perhaps)?


-- 

John Devereux

<ghelbig@lycos.com> schreef in bericht 
news:8b206752-b181-448d-9cca-0fb6203c9edc@y22g2000prd.googlegroups.com...
> On May 1, 11:03 pm, Peter <nos...@nospam9876.com> wrote:
>> mach7 <mach7so...@gmail.com> wrote
>>
>> >I know very little about USB, so excuse the naive question.  I'm
>> >looking for an IC that I can interface with a microcontroller (in my
>> >case, the ATMega32) that will let me communicate with a computer over
>> >USB.  My project involves large data transfers (for logging purposes)
>> >and serial / UART is too slow.  Any direction would be helpful.
>>
>> >Thanks,
>> >-J
>>
>> There are two major chips which implement a USB slave i.e. a way to
>> talk to a PC which has a USB port (a USB controller).
>>
>> One is Prolific in China, the other is FTDI in the UK.
>>
>> Prolific are absolutely crap on support - I sell a product with their
>> chip in and we never get any backup. Even buying them is a process...
>> But it works OK. It is cheaper of the two in volume.
>>
>> FTDI is much better (www.ftdichip.com) and they have good support.
>> price is about USD 2.50 in 1k quantities. Look up the FT232 or similar
>> - this gives a serial interface which you can connect to your
>> microcontroller's serial port directly.
>>
>> Both chips come with free drivers which create a virtual COM port
>> (VCP) within the operating system. FTDI do much more driver support
>> including various kinds of unix.
>>
>> I sell a product with the FT232 in it and we are very pleased with it.
>> We use the Prolific chip only because the product that uses it is made
>> wholly in China so we have no choice.
>>
>> There is a huge amount of work in the development of bug-free PC VCP
>> drivers. You would never want to write your own. Windows implements
>> predefined USB drivers for a few things like a USB keyboard/mouse,
>> parallel port, but curiously not a serial port which is why if you
>> want a USB serial port you have to provide the user with the VCP
>> drivers.
>>
>> One thing to consider is that the way windoze enumerates USB devices,
>> it creates a new COM port # every time you plug the *same* device into
>> a new USB port on the *same* PC. This is a right pain. The solution is
>> to put an EEPROM in your product and write a unique serial number into
>> this, and then the COM port becomes fixed to the device itself which
>> is generally much more helpful. Very few USB product manufacturers
>> bother with this EEPROM however. We do it on the FTDI chip based
>> product - it's very easy. FTDI provide a different set of drivers (not
>> VCP) which you install on a PC used to serialise your product and
>> these provide access to the EEPROM. You just write in a string which
>> contains a hash of today's date/time or whatever and then every one is
>> unique.
>
> I would NOT recommend FTDI.  Their software is poorly documented, and
> very buggy.
>
> Worst part is that when you point this out they respond with attitude
> rather than assistance.
>
> There are many, many other vendors to choose from.
>
> G.

I am in the process of selecting a USB to serial converter.

So G., what is a better solution than FTDI?
And why?

Frank

"mach7" <mach7sonic@gmail.com> wrote in message 
news:84affe4d-4aec-46e2-a36d-d4fa429f9008@x35g2000hsb.googlegroups.com...
>I know very little about USB, so excuse the naive question.  I'm
> looking for an IC that I can interface with a microcontroller (in my
> case, the ATMega32) that will let me communicate with a computer over
> USB.  My project involves large data transfers (for logging purposes)
> and serial / UART is too slow.  Any direction would be helpful.
>
> Thanks,
> -J

Like others I can recommend the FTDI chips. They have serial and parallel 
versions, PC-side device driver support is good, virtual COM port and a DLL 
with API. It's a very popular chip so there's support in Linux as well. 
There are cheap adapter boards if you can't do surface-mount.

TI and Silicon Labs have USB-RS232 bridges as well but I don't know how easy 
they are to use.

Andrew