Path: ...!weretis.net!feeder6.news.weretis.net!feeder8.news.weretis.net!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Roger Hayter Newsgroups: sci.electronics.repair Subject: Re: Re (2): USB functionality. Date: 12 Mar 2024 19:31:32 GMT Organization: Metazoon Lines: 43 Message-ID: <7189229973.1478ea1b@uninhabited.net> References: <2219572717.2fe80b82@uninhabited.net> <6449818651.785da3d8@uninhabited.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=fixed Content-Transfer-Encoding: 8bit X-Trace: individual.net G17/vLQl9GcIZoLajcJsxg79iztFmRk+Y8QkE64rbD2M/lP81N Cancel-Lock: sha1:cPiSulAe5Tibt43sLgfeXESmuaU= sha256:VlsWy9Ww8twNcEzMWafv/0KoUcFDfofX5A3grLNkVO0= User-Agent: Usenapp for MacOS X-Usenapp: v1.27.2/l - Full License Bytes: 2801 On 12 Mar 2024 at 19:27:04 GMT, "Dan Purgert" wrote: > 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. Usbc seems to have about 20 pins, that's why I asked. -- Roger Hayter