On Oct 10, 2006, at 6:02 PM, Joe Thielen wrote:
> - No RTC (Real Time Clock)? Oh no! I can understand, an RTC would
> probably add size and cost to the project. Any thought to adding this
> later? The next-gen? Yes I see we can get time via the network,
> but if
> this thing boots up and there is no network, it would be great to
> still
> have time (for a great number of purposes, especially a stand-alone
> access control system). In the FAQ it says that ntpdate is available,
> but I tried and it wasn't there. I assume this either has been
> removed
> (but is available for addition), or the FAQ is wrong?
> http://docwiki.gumstix.org/Template:FAQ/Questions/gumstix_set_its_time
The main reason for no RTC is powering the thing. If you need/want
one, it should be pretty trivial to add on a 60-pin daughtercard an
I2C (or SPI) RTC chip with a simple battery backup. We just haven't
done any battery stuff yet...
> - I would love to see more info on the wiki for GPIO. Right now, it
> seems that most of the I/O related info is targeted to LCD usage. I
> know what a wiki is and how to get info from it, but I've never edited
> anything. But aside from that, I don't know anything about GPIO,
> but am
> certainly going to learn, from the looks of it. Can we take the LCD
> stuff from the existing I/O FAQ and put that into a separate LCD
> section
> (or maybe the existing LCD section that right now deals with what LCDs
> work?). Then place INPUT/OUTPUT only stuff into it? Like basic-level
> stuff for us newbies... how to use a single GPIO line as an input
> or an
> output? I mean real basic here, like how, exactly, to make it so
> that a
> GPIO line can be used as an input (including any necessary circuitry),
> and how to access the GPIO to set or clear it for use as a relay
> trigger? Now, I think I saw the latter somewhere (Tips and
> Tricks), but
> it would be nice to have it directly there in the I/O FAQ. Does this
> make sense?
Yes. You can do that ;)
> - I love that it makes the Intel serial number available in
> /proc/cpuinfo. This is great for security oriented applications!
Note: this is not strictly the intell serial number. It's the serial
number from the flash chip, mangled through a function which spreads
the bit-entropy across the whole 64-bit space. In other words, if
the original serial numbers on the flash chip are 1, 2, 3, 4, 5 for 5
separate gumstix, the final "serial number" which you get in /proc/
cpuinfo (also in the kernel as the serial_high/serial_low data) will
looks completely different from each other, rather than only
differing in the low-order bits. The entropy-spreading is done so
that MACs which get calculated from that serial number end up being
less likely to collide.
> - I think adding some things to the "Getting Started" tutorial
> would be
> great. Or maybe a different place would be appropriate... but serious
> BASIC level stuff here... like the fact that when I was doing research
> on this stuff, I noticed the 60 and 90 pin connectors, but from the
> docs
> and available pics it was hard to tell that they just 'snapped'
> together... no ribbon cable necessary. SIMPLE stuff like that. And
> also for power. I assumed since I bought the "pack" that the one
> power
> supply would work. But I didn't actually "know" it until I got it all
> put together and it worked. In fact, I missed the fact that the 400xm
> connex doesn't even have a power jack on it. I see a power jack on
> the
> waysmall-STUART and the netMMC, but I didn't know if it mattered. I
> plugged my power supply into the waysmall-STUART and was happy to see
> that it distributes power to all modules. This is great, but I think
> this should be documented in a single place, for those who are looking
> for info on this great device, but, like me, got very wary quickly
> digging through the Wiki when I didn't even know if I was going to buy
> this thing or not. Just something to keep in mind...!
A "Complete beginner" or "Idiot's guide to gumstix" which goes
through this stuff might not be a bad thing to add a link to at the
top of the "Getting started" tutorial. If you want to get a page
like that started on the wiki, please feel free to. I'd try not to
change the flow of the current tutorial too much though, because
while I think you're right it would be nice for some folks if they
had this info, most people will have the boards in hand when they're
going through the tutorial, and the "they just snap together" stuff
will be obvious enough that they won't want to have to wade through a
bunch of that kind of info before getting to the part where they can
actually log into the 'stix and start playing.
> Anyway. These are my first thoughts after playing with this baby
> for 30
> minutes. I seriously look forward to seeing what I can do with it!!!
>
> And a BIG thank you to everyone on the mailing list in advance for all
> the dumb questions I'm going to ask. And another BIG thank you to
> everyone who puts info into the Wiki that I am going to be busy
> devouring!
Our thanks too -- and to people like you who keep pushing the state
of the wiki forward :)
C
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