Pi HOWTO

[Eric S. Raymond]

Hal Murray <hmurray at megapathdsl.net>:
> 
> I think there are two interesting variables: the HAT and the case.  There is 
> a 3rd minor variable of Pi-3 vs Pi-2 vs B+

I've not going to try covering the older variants with the 26-pin header.
Gotta draw the line somewhere and that seems like a good place.

> I think you should write up something that works and put the rest of the 
> options in an appendix.  (or something like that)  You can add a few 
> references to the appendix at the critical places in the main text.

Yes, I'm handling what little we know about the Odroid that way, in an appendix.

But for the three HATs I'm taking a different tack.  They're all described
in the mainline text, but the description is factored so most parts are
independent from specific hardware.

> I think all the GPS HATs I've seen put the PPS on a different pin.  It may be 
> worth putting a small table at the right place in the text.

Already done:

|============================================
| Logical pin   | Physical pin  | HAT
|   GPIO04      |      P1-7     | Adafruit
|   GPIO18      |      P1-12    | Uputronics
|   GPIO05      |      PI-29    | SKU 424254
|============================================

And that's an example of how I'm handling hardware variations.

> The case in the list I sent out recently works with the Adafruit HAT if you 
> use the internal antenna.  I think you can get the cable out the slot for the 
> ribbon cable if you want to use an external antenna.

Hm.  Remind me what that case us? I should out it in the draft.

> The picture for Gary's no-soldering HAT shows an antenna connector that won't 
> fit in that case.
> 
> There is at least one "case" that is two clear plates connected by 4 corner 
> posts.

What I'm doing now is recommending any flat-topped case with an exterior 30mm
height.  If we can be more specific than that, and name working cases as
examples, we should.
-- 
		<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>