anelok: the Y-Box paint job, part 3: action

Werner Almesberger werner at
Sun Nov 17 19:46:03 EST 2013

Paul Boddie wrote:
> but I suppose the Y-Box is effectively an unpowered hub

It's much more primitive than that:

It's basically the equivalent of a Y-cable, only more complicated.
I'd of course have preferred simply finding a suitable Y-cable,
but - after looking at about a hundred items on Alibaba - it seems
that combination doesn't exist on the market.

Given enough volume, one could of course just get a custom cable
from ACME (Amazing Chinese Make Everything).

The only component that has an active role is diode D2. What it
does is block power coming from the wrong port, so that the device
will not appear to be "running" (LED is on, keyboard and Anelok
are powered) yet fail to work (because the data lines aren't
connected) if you get the two Micro USB B ports wrong.

> and where the Anelok appears as a peripheral 
> to the PC but as a host to any connected keyboard.

It's only the second half, the host for the keyboard. The PC only
acts as a power supply (a USB wall wart will work just as well).
If you want communication as well, you need to use RF (and a
second USB port.)

This is admittedly a clumsy solution. Its main purpose is to let
us experiment with this sort of connectivity. If it leads to nice
use cases we can think of a more elegant approach.

An "intelligent" Y-Box along the lines of what you've described
would certainly be an interesting option. But then, three USB
ports ...
- device + host + host (Anelok is device),
- device + host + hub (Anelok is device), or
- device + device + host (Anelok is host)
..., yuck.

- Werner

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