( where do these people come from ??? )
From USA ? No wonder USA outsource every little bit to India.
Pozdrawiam.
-- RusH //
hamilton: OK, thats what i was wondering...thats why i asked. No need to be all pissy about it.
Hi Tony,
In groups like these, it is good netiquette to at least look on the manuals before just asking question that would have been obvious if you spent any time at all.
It is obvious that you never even tried.
I enjoy helping a student or fellow engineer with simple and difficult problems. But this was just dumb.
I hope something was learned.
I could have just said "dumb a**" and just let you figure it out yourself.
hamilt>
"hamilton" skrev i meddelandet news:4196b41f$1 snipped-for-privacy@omega.dimensional.com...
Not 100% USB compatible, but it is pure S/W and appears to work It uses an AVR though!
Wow, that is pretty awesome. His site is not too clear, but he claims
100% compatibility with Low speed usb. What is not compatible?It has got to be pretty tough running at 12 Mips to bit bang 1.5Mbit per second USB, which requires differential signaling AND bit stuffing. The processor would have 8 instructions per bit. The maximum packet size is 8, so the max number of bits is 8 (sync) 8 (data0/1) and 8*8 data bytes plus 16 bits crc. So worst case it is 96 bits of transfer plus bitstuffing which could worst case add 16 bits to a total of 112 bits. This has to be sent without gaps in 75 microseconds.
I haven't looked at his code, and I don't know the avr, but maybe an inline chunk of code could do that? I bet he does have some problems in meeting spec for the ACK packet which has to follow reception of a data packet in a few bit times. Especially if he checks the crc. When I get some time I'll look at his code, but it still is an achievement with that slow a processor.
Regards, Steve
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