There are a number of factors that determine the RS232's max speed [including cable length and processor clock speed]. I think I've seen that RS232 can get up to 230.4K baud. It's interesting what you said about the FTDI interface's top speed. I wonder if it's because you aren't actually using an RS232 interface but just the processor's USART. [Maybe the Processor's USART has a higher top end than RS232.] The USBKey [AT90USBKEY] can be found at: http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3879 [Non-text portions of this message have been removed]
Message
Re: USB interfacing
2008-09-02 by David Appleton