Good question. The general idea was that the FS functions work with the
higher level logic and the full owq structure. The OW_ function deal with
the actual byte sequences sent to and from the slave.
The distinction isn't alway clear, or followed perfectly (it is a 10
year-old project). I'd be happy to offer style suggestions on your code.
On Fri, Jan 20, 2012 at 1:37 PM, Eloy Paris <[email protected]> wrote:
> Hi Roberto,
>
> On 01/20/2012 01:32 PM, Roberto Spadim wrote:
>
> > i think FS is for fusefs not?
>
> Yes, it seems like the FS_xxxx() functions are intended to interface
> with the filesystem side of things, but I am wondering if there are do's
> and dont's/guidelines/recommendations regarding what type of code to put
> in each "class" of functions. The example I provided, i.e. where to do
> internal representation conversions, is one that comes to mind as
> something I'd like clarification on.
>
> Cheers,
>
> Eloy Paris.-
>
> >
> > 2012/1/20 Eloy Paris<[email protected]>:
> >> Hello,
> >>
> >> I'm adding owfs support for a new device and am a bit confused regarding
> >> conventions/best practices and what to do in the FS_xxxx() and OW_yyyy()
> >> functions.
> >>
> >> Using ow_1820.c as an example, to read a temperature from a DS18x20
> >> sensor, we have:
> >>
> >> FS_10temp() is the read function used for the "temperature" entry in the
> >> struct filetype DS18S20[] array.
> >>
> >> FS_10temp() in turn calls OW_10temp(),which ends up performing the
> >> necessary bus transactions or calling other OW_yyyy() functions that
> >> perform more bus transactions (in the ow_1820.c case, OW_10temp() sends
> >> the "start conversion" command doing a direct bus transaction, and then
> >> calls OW_r_scratchpad() to read the scratchpad).
> >>
> >> An important thing done in OW_10temp() is that it converts the DS18x20
> >> representation of a temperature to a float.
> >>
> >> One difference that I can see between the FS_xxxx() and the OW_yyyy()
> >> functions is that the FS_xxxx() functions have the following
> declaration:
> >>
> >> ZERO_OR_ERROR FS_xxxx(struct one_wire_query *owq)
> >>
> >> and the OW_yyyy() functions are basically free-form.
> >>
> >> I have also noticed that the FS_xxxx() functions do not do bus
> >> transactions directly. Instead, they seem to call OW_yyyy() functions. I
> >> have not looked much, though, so I don't know if there are any
> exceptions.
> >>
> >> Now, my device also provides different values that require conversion
> >> from a device internal representation to a more common representation
> >> (like a floating point number). Should I be doing these conversions in
> >> FS_xxxx() or in OW_yyyy() functions? If I follow the "convention" in,
> >> for example, ow_1820.c, then it would have to be OW_yyyy(), but I wanted
> >> to confirm.
> >>
> >> And more in general, are there any guidelines on the use of FS_xxxx()
> >> and OW_yyyy() functions, like what should be/should not be done in each
> >> "class" of function?
> >>
> >> Thanks in advance for any insight.
> >>
> >> Cheers,
> >>
> >> Eloy Paris.-
> >>
>
>
> ------------------------------------------------------------------------------
> Keep Your Developer Skills Current with LearnDevNow!
> The most comprehensive online learning library for Microsoft developers
> is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3,
> Metro Style Apps, more. Free future releases when you subscribe now!
> http://p.sf.net/sfu/learndevnow-d2d
> _______________________________________________
> Owfs-developers mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/owfs-developers
>
------------------------------------------------------------------------------
Keep Your Developer Skills Current with LearnDevNow!
The most comprehensive online learning library for Microsoft developers
is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3,
Metro Style Apps, more. Free future releases when you subscribe now!
http://p.sf.net/sfu/learndevnow-d2d
_______________________________________________
Owfs-developers mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/owfs-developers
