[time-nuts] web presentation of data

[mike cook]

Le 07/08/2012 17:56, Chris Albertson a écrit :
> On Tue, Aug 7, 2012 at 6:45 AM, Jim Lux <jimlux at earthlink.net> wrote:
>
>> On 8/6/12 10:43 AM, Chris Albertson wrote:
>>
>>> On Mon, Aug 6, 2012 at 8:34 AM, Jim Lux <jimlux at earthlink.net> wrote:
>>>
>>>   what would be useful is to have some sort of "plotting engine" that is a
>>>> canned webpage (or stored locally on the user/client computer) that can
>>>> ingest fairly raw data from a URL..
>>>> <snipped>
> So the web server is inside an Arduino?  Yes can't run GNUplot there.   Why
> not have the Arduino produce either Postscript or PDF?  It is very easy to
> draw a graph in Postscript.
>   <snipped>
> Also everyone already has the display engine.  PDF is very much like
> Postscript. but I think Postscrip in "EPS" form is easy to create inside an
> Arduino,
>
One good reason for doing as little as possible in a micro-controller is 
that they are often used to collect raw  data with as little latency as 
possible. Doing web serving on a single slowish core in that case is not 
a good idea. I have a bunch of Soekris doing data collection and if I 
start to do compute intensive tasks on one, it skews the timing, so I 
use a completely independent one to do the web serving, with the data 
collectors providing access to data via nfs which does not seen to 
impact the timing much even though I can't guarantee that requests are 
satisfied in otherwise idle time . I like the idea of  client side 
graphing. It probably exists already somewhere though I haven't checked 
details - RGraph pops up with google.

-- 
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