[MinnowBoard] M.2 (NGFF) from Minnowboard Max HS header

[Michal Šmucr]

On 17.2.2015 17:47, Darren Hart wrote:
> I have investigated M.2 some for use on the MAX. I was disappointed in the
> selection of WiFi cards available, as well as the specificity of the
> keying (not ideal for a general purpose connector). It certainly has some
> advantages, like size and the potential for 10Gbps storage (with 2 PCIe
> lanes).
>
> You would need to verify all the required signals for each connector and
> see if you have them all on the current High Speed Expansion (HSE). If you
> restrict yourself to just SATA on the B/M connector you should be able to
> get by with the single PCIe lane available on the HSE, otherwise you'll
> need a bridge.
>
> Really, you just need to enumerate the signals and start checking them
> off...
>
> --
> Darren

Hi Darren,
thank you for your insight.

I agree, keying seems to be quite mess for me :)
I'm fine with particular restriction to SSD and WLAN card.
My main concern was future availability of non M.2 devices besides eBay, 
but maybe I'm just overthinking it.. Just came to Molex website,  to 
check for Mini PCIe sockets and found it all in legacy section :) So 
that ignited my curiosity and I've found all WLAN cards and SSDs by 
Intel from 2013 onwards were released also in M.2 format. Recent models 
(7265 and 8260 cards probably exclusively.. https://wikidevi.com/wiki/Intel)

You're true with checking of used pin signals by devices, I've done it 
with 530 M.2 SSD datasheet and there shouldn't be much difference 
between mSATA (basically differential SATA TX, RX, I2C, power and couple 
of grounded pins).
Situation will be of course different when some SATA Express device will 
be used, but this isn't that case.

With WLAN card pinout it is more complicated.. as I haven't found 
complete M.2 specs (not member of PCI SIG) and Intel provides only 
product briefs for WLAN cards vs. full datasheets for its SSDs.

Anyway, i've found interesting thing 
http://www.hwtools.net/Adapter/M2MU2.html
So maybe, it will be just matter of mechanical adapter in this 
particular WLAN card case and design with mini PCIe socket will be fine 
and future upgrades can be possible with the adapter.

Best regards,

Michal