[Thumbgps-devel] the serial alternative/radio noise

[Dave Taht]

On Mon, Mar 12, 2012 at 3:06 PM, Eric S. Raymond <esr at thyrsus.com> wrote:
> Dave Taht <dave.taht at gmail.com>:
>> I AM curious if there is one of the gps boards we've looked at than
>> can 'just fit' on this header. Or, for that matter, a RTC.
>
> How often do I have to sing the "this kind of customization won't scale"
> song?

Cats, herding.

I note that in the early stages of any project, I tend to appreciate
all sorts of blue-sky thinking, rather than tie down to any one goal,
and try to encourage such in others. I guess in part what drives me in
suggesting alternatives (and please note my alternative above was
intended as a lead-in into the noise question more than an actual
suggestion), is that I would like to find markets for a 'new device',
that 'does new stuff', that justifies the manufacturing run, more than
a 'usb gps with hyper-accurate pps and time output' may, as a
differentiator.

To give an example I've long had an interest in climate change, in
particular, in the lack of good data from equatorial zones. I had
intended while I was still working on my mesh project in Nicaragua to
co-locate weather stations with at least some nodes, (multiple open
source and open hardware alternatives are available, google for them),
and in that case - given that the network might be down or
non-existent, having good time for the samples also seemed good (as
well as a good location indicator! See
http://www.teklibre.com/~d/b4barrios10.kml for an interactive map of
the sites I'd surveyed with my handheld gps below san juan del sur,
Nicaragua).

http://oscirrus.see-do.org/schematics/schematics.html for one weather
station (this isn't the one I was thinking of at the time, tho)

Anyway, this is a potential market use-case for the hardware as
discussed thus far. There are no doubt others.

>
>> Now, I actually brought this up because in looking at this I realized
>> anew what a huge radiator of various forms of electronic noise this
>> is. - 2.4ghz and 5.x ghz radios, and a variety of possible waveforms
>> from the cpu - and I'm curious as to what extent gps is affected by
>> these frequencies.
>
> You and I have observational evidence that it's not an issue even for
> low-end, poorly-shielded hardware,

I have observational evidence that we have problems with many kinds of
hardware and the cause is undefined, and varies by manufacturer.


> --
>                <a href="http://www.catb.org/~esr/">Eric S. Raymond</a>



-- 
Dave Täht
SKYPE: davetaht
US Tel: 1-239-829-5608
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