[Cryptech Tech] Alpha layout done (not a joke)

[Peter Stuge]

Gerbers look great at a glance.

Jacob wrote:
> if those headers are for a dev option and not for the end-user, I'd
> recommend to change them to 0 Ohm resistors (preferably 0402 or, if
> you wish for ease of "basement soldering", 0603).

That would make it much more difficult for software devs to try other
USB options, which kind of defeats the purpose of the header. :\

Removing (maybe destructively, think scalpel :) the FTDI part and
attaching a daughterboard is easier than reworking jumpers.


> USB signalling requires special care

As a signal integrity optimization the headers could be left
unpopulated, the copper tunnels inside each via then indeed still
make for small stubs on the data lines, but I guess that high speed
will work reliably anyway, maybe even with headers populated, if the
USB cable is short.


> If you leave it as it is now, the USB interface will still work,
> albeit at reduced speed due to re-negotiation of lost packets.

I think this may be too pessimistic, and even if not then reduced
speed may be acceptable, given the benefit of easier experimenting
with alternative USB interfaces.


//Peter