no KL27; Y-cable news (was Re: Anelok: one more MCU - maybe an idea for later)
werner at almesberger.net
Sun Dec 28 18:46:41 UTC 2014
> KL27 32-QFN 256 kB MKL27Z256VFM4 3.185
Oops, this one wouldn't do: the USB in KL27 (and relatives: KL17, KL43,
maybe more) is only device ("slave" as Freescale call it), not OTG.
Speaking of OTG, it seems that Y-cable research has made some important
breakthroughs since the last time I checked, and they have now caught
up with our needs. Here are a few cables that seem to be roughly
equivalent to the original Y-box:
- cheap, but cable is a bit short:
- a bit longer (19 + 30 cm):
- here's one from a reputable brand. Alas, it seem that they're
replacing this one with a model that has a Micro USB 3.0 connector:
- one more, this time from eBay:
Interesting detail: "does not support OTG phone or tablet charging".
Hmm. VBUS not connected between USB A male and Micro B male ? That
But then, they have some other peculiar ideas: "the disk must be
formatted as FAT32." Must be one heck of a smart cable ! :)
- also available with angled Micro B:
Anyone care to get one of these critters and measure how it's
connected on the inside ?
It's interesting that they all are Micro B not Micro A. I wonder what
they do with the ID pin. But if the industry chooses to ignore AB and
just uses B for both roles, then I'll be the last to complain: while
the shield of a Micro B receptacle will reliably stop a reversed plug,
Micro AB - and I guess also Micro A - relies on a fragile-looking piece
of plastic for this.
Availability of Y-cables also means that developing the Y-box is less
important and we may end up not needing it at all.
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