AT90USB128 to 802.11 wifi adapter

schrieb

This depends on your application. For the typical networking stuf´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" skrev i meddelandet news:457521d2$1 snipped-for-privacy@news.ecore.net...

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.

... snip ...

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.

"Ulf Samuelsson" schrieb

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

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 týpes of applications.