AT90USB128 to 802.11 wifi adapter

Anyone have any comments on the feasability of connecting a Atmel
AT90USB128 (which has usb host mode interface) to a 802.11g USB adapter
based on something like the Zydas ZD1211?

Seems like it could be a cheap and flexible solution-- but quite a bit
of work, and would require a USB analyzer.  The ZD1211 is supported by
linux, so that would be a good reference, and Atmel provides a simple
host mode example for the AT90USB (for connecting to a keyboard or
mouse).

Too bad USB analyzers are still so expensive.  I even did a little
searching to see if I could find one for rent, but couldn't find any
references.

thanks.

<jakeb221@gmail.com> schrieb
> Anyone have any comments on the feasability of connecting a Atmel
> AT90USB128 (which has usb host mode interface) to a 802.11g USB adapter
> based on something like the Zydas ZD1211?
>
This depends on your application. For the typical networking stuf&#4294967295;f you will 
need a TCP/IP stack too. I doubt that the performance of the ATMEGA is 
sufficient to support both, the byte-by-byte handling of the USB WLAN 
adapter and the TCP/IP communication.
However I could imagine applications which use the 802.11 WLAN connection on 
a packet level i.e. without TCP/IP and in this case this sounds like an 
interesting idea.

/Roland

"Roland Zitzke" <KONULRABFBQR@spammotel.com> skrev i meddelandet 
news:457521d2$1_1@news.ecore.net...
>
> <jakeb221@gmail.com> schrieb
>> Anyone have any comments on the feasability of connecting a Atmel
>> AT90USB128 (which has usb host mode interface) to a 802.11g USB adapter
>> based on something like the Zydas ZD1211?
>>
> This depends on your application. For the typical networking stuf&#4294967295;f you 
> will need a TCP/IP stack too. I doubt that the performance of the ATMEGA 
> is sufficient to support both, the byte-by-byte handling of the USB WLAN 
> adapter and the TCP/IP communication.
> However I could imagine applications which use the 802.11 WLAN connection 
> on a packet level i.e. without TCP/IP and in this case this sounds like an 
> interesting idea.
>
> /Roland
>

The nice thing about TCP/IP is that if you lose a packet,
the protocol will ensure it will be resent.
Talked to a customer the other day, and they need to send 16 bits of data
every three seconds over TCP/IP/WLAN , and I do not see why this
would be a problem for the AT90USB1287.

-- 
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 

Ulf Samuelsson wrote:
> 
... snip ...
> 
> The nice thing about TCP/IP is that if you lose a packet,
> the protocol will ensure it will be resent.
> Talked to a customer the other day, and they need to send 16 bits
> of data every three seconds over TCP/IP/WLAN , and I do not see
> why this would be a problem for the AT90USB1287.

Sounds like overkill to me.  Just include a timestamp with the data
and use IP.  The receiver can then detect missed packets and
possibly interpolate.

-- 
Chuck F (cbfalconer at maineline dot net)
   Available for consulting/temporary embedded and systems.
   <http://cbfalconer.home.att.net>

"Ulf Samuelsson" <ulf@a-t-m-e-l.com> schrieb
>
> The nice thing about TCP/IP is that if you lose a packet,
> the protocol will ensure it will be resent.
> Talked to a customer the other day, and they need to send 16 bits of data
> every three seconds over TCP/IP/WLAN , and I do not see why this
> would be a problem for the AT90USB1287.
>

In this specialized case it would most likely work. The only question is 
wheter there's a way to get by with the internal memory of this controller.
There are TCP/IP stacks around for the AVR like the Ethernut but they do 
require external RAM.
Very often the rational behind using TCP/IP and not some other low level 
protocol is that the embedded hardware needs to talk to a UNIX or Windows 
host and these machines handle IP stuff easily.
In such case it might even be possible to get by with a UDP communication 
and manually implement a resend feature.
This requires of course that there is no risk of loosing the packet 
ordering.
/Roland

Roland Zitzke wrote:
> "Ulf Samuelsson" <ulf@a-t-m-e-l.com> schrieb
>>
>> The nice thing about TCP/IP is that if you lose a packet,
>> the protocol will ensure it will be resent.
>> Talked to a customer the other day, and they need to send 16 bits of
>> data every three seconds over TCP/IP/WLAN , and I do not see why this
>> would be a problem for the AT90USB1287.
>>
>
> In this specialized case it would most likely work. The only question
> is wheter there's a way to get by with the internal memory of this
> controller. There are TCP/IP stacks around for the AVR like the
> Ethernut but they do require external RAM.

This chip has 8 kB SRAM which helps a little.
As long as you only use 1-2 transmit buffers you can live with
very low amount of memory.
This will have terrible performance when accessing over WAN,
but on a LAN it is OK, for these t&#4294967295;pes of applications.

> Very often the rational behind using TCP/IP and not some other low
> level protocol is that the embedded hardware needs to talk to a UNIX
> or Windows host and these machines handle IP stuff easily.
> In such case it might even be possible to get by with a UDP
> communication and manually implement a resend feature.
> This requires of course that there is no risk of loosing the packet
> ordering.
> /Roland

-- 
Best Regards,
Ulf Samuelsson
ulf@a-t-m-e-l.com
This message is intended to be my own personal view and it
may or may not be shared by my employer Atmel Nordic AB