Path: ...!news.mixmin.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Dan Purgert Newsgroups: sci.electronics.repair Subject: Re: Re (2): USB functionality. Date: Tue, 12 Mar 2024 19:27:04 -0000 (UTC) Organization: A noiseless patient Spider Lines: 41 Message-ID: References: <2219572717.2fe80b82@uninhabited.net> <6449818651.785da3d8@uninhabited.net> Injection-Date: Tue, 12 Mar 2024 19:27:04 -0000 (UTC) Injection-Info: dont-email.me; posting-host="08af59b90df807c866dbf133bc03d33d"; logging-data="496376"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+DTBzICJxPuAWAXZmgNmyKeWr7AcOB/pA=" User-Agent: slrn/1.0.3 (Linux) Cancel-Lock: sha1:4XAotaIOnjw+nLflsdIZBC58FVU= Bytes: 2723 On 2024-03-12, Roger Hayter wrote: > On 12 Mar 2024 at 16:29:31 GMT, "peter@easthope.ca" wrote: > >> In article <2219572717.2fe80b82@uninhabited.net>, Roger Hayter >> wrote: >>> But can even USB-C accept a signal input (keyboard and mouse for >>> instance) and unrelated signal output (audio for instance) on the >>> same physical socket? I ask only out of curiosity. >> >> The setup is rarely tried. Appears that nobody can reply. >> >> A keyboard or mouse sends tiny amounts of data; a few bytes per >> second. In principle the link should be able to fit that in without >> significant drop-outs in audio output. WIth so many details involved, >> a general answer is difficult. When all else fails, we can test and >> see what happens. =8~) >> >> Regards, ... P. > > So you could use an overarching protocol which was bilateral (ethernet > anyone?) and send and separate messages both ways. What I was aksing was > whether within the USB protocol there was provision for using some pins in for > one electrical signal (bi or uni-directional) and other pins for another > electrical signal. Because that would be the only way to do it without special > software on at least one of the devices. > There's only one set of pins (well, two sets if you count USB2 / USB3 -- but you can only use one set at a time). USB2 -> D+/D- (Bi-directional / Half Duplex) USB3 -> TX1+/TX1- and RX2+/RX2- (optionally Full Duplex, IIRC) As I recall the "Tx" pair is "Host Transmit to Peripheral", and "Rx" is "Host Receive from Peripheral", but it's been a while since I read up on the USB3 / USB-C implementations. -- |_|O|_| |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860