[Tinyos-devel] external (nx*) types and floating point

[David Gay]

On Tue, Oct 9, 2007 at 9:07 AM, David Gay <dgay42 at gmail.com> wrote:
> There's currently no nx_float / nx_double type that would allow use of
>  floating point in protocols.
>
>  Two questions:
>  - how necessary are such types? (w/o them, you have to figure out some
>  integer encoding for any real numbers you have to deal with)
>
>  - does anybody have some portable code (and not too large...) for
>  converting an array of bytes to a float/double? (that's the main
>  sticking point as far as I'm concerned)
>
>  Some additional comments:
>  - specifying these types as IEEE 32 and 64-bit numbers seems reasonable
>
>  - I'm reluctant to include platform-specific code w/ the nesC
>  distribution to deal with nx_float/nx_double, as it feels like it
>  would make nesC maintenance more painful
>
>  - we could actually  define nx_float/nx_double in TinyOS (on a
>  per-chip or per-platform basis, e.g.) - external types are defined by
>  a magic (undocumented) attribute, so can fairly easily be added
>  independent of nesC

Did anyone care about this? Offhand, it did seem worthwhile doing the
last proposal (defining nx_float/nx_double for each MCU).

David