Werner Almesberger wrote: > Joachim Steiger wrote: >> - i really like my mini-usb. (for mechanical, practical and spread in >> the real world) > > Me too. Of course, if the market really switches to micro-USB, the > scenario may be very different in a few months. If only Nokia use > micro-USB, we'll be of course happier with mini.
;) > We may be able to design for one, and change our minds later. The > problem here is mainly the case. Apparently, it's fiendishly > expensive and time-consuming to make the molds, but some changes > can apparently be accommodated without too much pain. > >> - the N8xx series is the only device i know i were near which does OTG >> as far as i know. > > I don't know enough about OTG to tell whether it's actually good or bad. > Of course, if it becomes popular, we'd look rather silly with our own > hack. indeed. i also see nothing which stands in the way of having the usb-b do all what otg needs on a electrical/protocol level when the soc does all that for us. >> * i would rather like A due to the more widespread of cables and >> devices, but its propably too big > > Yeah, I'd have to dig quite deep into my gadgets box to actually > find something that does mini-A. > >> * put a single 2-positions switch below the battery flap to switch this >> whole port to jtag. > > That's where your proposal gets a bit messy. It means that we couldn't > have JTAG/serial console and host mode. So if anything blows up there, > we're blind. Not the end of the world (after all, we survive quite well > on the PC, without having all these niceties), but unpleasant. when usb HOST is failing you can still debug that via ssh over the usb-client mode/charger port (or kernel-gadget from cdc-ethernet to cdc-adm ;)) so only when usb is dead completely you cannot debug usb-host, only the otg port via jtag >> please let me know what you think > > The host vs. JTAG/console exclusion aside, it has a nice ring to it. > > One bit that may be troublesome is the USB switch, though. USB is very > finicky about line impedance, reflections, an all that, so making a > switch that doesn't distort the signal too much may be difficult to > make. yes. but its only usb1.1 12mbit, not the 480mbit otg capable usb which will go through the switch/switched latch so this should be doable without too much hassle. i bet even a stone-old cmos 4066 latch would do. -- Joachim Steiger developer relations/support _______________________________________________ hardware mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/hardware
