[Tinyos Core WG] Meeting: September 20

[henri dubois-ferriere]

one thing about tutorials:

what do people think about putting them on a wiki, so that (hopefully)
the burden of correcting/maintaining them over time could be  shared
with the people who actually use them.

i think the 1.x tutorials progressively became very stale and somewhat
diverged form the actual evolution of the 1.x release train, and maybe
wikifying the tutorials can improve things in 2.x

thoughts?

On 20/09/06, Kevin Klues <klueska at gmail.com> wrote:
> Here are the meeting notes (on wiki as well as here)
>
> http://tinyos.stanford.edu:8000/TinyOS_2.x_WG/9.20.2006
>
> ------------------------
> = TinyOS 2.x WG/09.20.2006 Meeting Notes =
> ------------------------
>
> = Agenda =
> ------------
>  * Tutorials
>  * TEPs 101 + 109
>  * TEP 117
>  * TEP 103
>
> = Participants =
> ----------------
>  * Kevin Klues, Wustl
>  * Phil Levis, Stanford
>  * David Gay, Ben Greenstein, Intel
>  * Vlado Handziski, TU Berlin
>  * Phil B, Jonathan, Gill, Arch Rock
>  * Prabal, Berkeley
>
> = Action Items =
> -----------------
>  * Everyone needs to start wroking on the tutorials they signed up for
>  * Phil B. will look at meeting notes from last time, Henri's email, and
> talk with Jonathan to work on revising TEP 117
>  * Vlado will look at gcc compiled code to determine inefficiency of
> returning struct values for ADC configuration
>  * Gil wil start chagning implementation of sensor drivers to work top of
> new HIL interfaces once Vlado is finished with his evaluation
>  * Jonathan will get stm25p flash implementation up to date with new Storage
> interfaces on a branch that David will create
>
> = Next Meeting Agenda =
> ------------------------
>
>
> = Discussion Notes =
> --------------------
>
> == Status ==
> Phil: Tutorials have been signed up for, but some remain
> Phil: Easy to debug and don't take as long to write
> Phil: Would engourage peole to sign up for them
> Prabal: Which still need to be written
> Phil: Six tutorials remain that need to done, 3 not yet volunteered for
> Phil: The three are concurrency, SDK, and storage not yet volunteered for.
>       * Prabal - Storage
>       * Kevin - Power management
>       * Henri - Platforms and Network Protocols
>       * David - SDK
>       * Phil - Concurrency
> Phil: Usually takes about 4 hours or so as an estimate
>
> In regard to TEPs, we need to provide summary of changes, and not just
> send along new version.  We could alternatively do a cvs diff if you provide
> the version in cvs it should be diffed against
>
> == TEP 117 ==
> Updated to reflect newest I2C interface and associated flags.
> Changed result_t to error_t
>
> Vlado: Wanted USART discussion included as well
> Phil B: Thats not in there
> Phil: Talk to Jonathan, and lets defer it till next week then
> David: Henri's email needs looking at (He says TEP 109, but he really means
> 117)
>
> == TEP 101 ==
> Was out for review and TEP now addresses these comments.
> Four major changes
>  * Removal of HAL2 and intro of HIL for ADC
>    * Has platform independent data interface
>    * Pass suitable configuration struct that is platform specific
>    * Read interface remains uninterpreted and conversion functions all on
> next level
>    * Plan to submit additional TEP for how to convert into engineering units
> when connecting to sensors
>  * Usage of DMAs to implement fast version of reaadstream
>    * Required changes to semantics of read operation
>    * Until now, read took confiiguration as parameter
>    * Once device granted to read, it would configuree it, do conversion and
> give back result
>    * Now dma needs configuration as well, so takes too much time
>    * Solution: Provide configuration command to user rather than including
> it in read as a parameter
>    * User needs to call configure command before before using ADC -> used to
> limit delay on configuration
>    * Before was paramter of read, now have separate command so you can
> better control timing
>  * Removed long discussions of roundrobin arbitration
>    * Points now to TEP 108
>
> Phil: appendix C should refer to HIL, not HAL, just one letter change
> David: inefficiency of returning a struct, does gcc produce code storing
> everything on stack or in registers?
> Vlado: wanted to ask about this actually, could potentially return a
> pointer...
> David: Have you looked at the code thats produced?
> Vlado: No, we should definitely check though
> David: Enough inlining could make this all efficient anyway, without needing
> to return pointer
> Phil: Just look at the code and see what is actually happening, it may work
> great, so lets not speculate yet on how to "fix" it
>
> Phil: Do chagnes sound reasonable given TEP 109
> Gil: Haven't actually implemented sensors on top of new interfaces, but
> seems reasonable and will most likely work
> Vlado: Its not really much of a change in implementation, just a change in
> abstraction organization
>
> == TEP 109 ==
> Clarification of MAY, SHOULD, MUST
> Make comments about providing unit conversion interface is now SHOULD not
> MUST
> Virtualization at sensor HIL is now capital SHOULD, just suggestion (but
> strong suggestion)
> Naming convention is now a MUST
> MUST for breaking up sensor specific drives s
> Examples still don't reflect chages to TEP 101
> Just need to make these small changes and check in new version
>
> Phil: why would one never not to virtualize a sensor?
> Gil: Look in appendix C, split phase, so no need to virtualize
> Phil: I see, that makes sense.  What time frame do you have for implementing
> 109 based on 101 changes?
> Gil: Maximum two weeks
> Vlado: ADC code not yet in tree, but will be soon
> Phil: Lets check out assembly and make sure that the new code is reasonable
> to drive implmentation discussed in TEP 109
>
> == TEP 103 ==
> Small changes to table giving example of each chip, can look up things in
> data sheet now for more detail
> Major change - Section (Storage in Tinyos-2.x) rational for architecture
>  * follows lots of suggestions given by David Moss
>  * leaves door open for using both low level, and high level implementations
> Fixed some typos
> More careful about use of SHOULD and MUST
> Interfaces not actually in the TEP, but just pointer to them (reference with
> html link)
> Might be worth making Block storage more general based on David Moss's
> comments
>   * provide lower level abstration (allows erase, bunch of consecutive
> writes not to same bytes, sync, check crcs)
>  * removal of verify/commit interface, need to read crc explicitly and check
> it yourself
>  * can do more low level operations now
>  * take a look at my followup email to last meeting as its more coherent
> than whats said here
>
> Vlado: need to fix table in TEP to be proper docutil table
> Jonathan: Changes seem reasonable, would still work with Deluge. Verify not
> really necessary, sync more useful.
> David: can you do implementation of smt25p to use new code, I'll put it on a
> branch for you to check out
> Jonathan, sure, should be trivial, can get it done by end of the week.
>
> Phil: interface signature should be appendix rather than pointing to tree
> directly, useful to see them right there
> David: I agree, I'll do it that way
>
> == Misc ==
> Meeting time change:
>  * Preferences for wednesday has won out!!!
>  * new tinyos-2.0 WG meeting time is Wednesdays at 9:30am. PST
> HIL meeting discussion:
>  * Lets just do it over email
>  * Vlado will send out initial email
>