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- Subject: Re: Reducing Lua memory footprint - need help
- From: "Bogdan Marinescu" <bogdan.marinescu@...>
- Date: Thu, 16 Oct 2008 22:38:54 +0300
> IMHO doing PCB's at home is a bad idea, when there are so many good,
> affordable PCB proto houses.
Precisely. If you live in the US, that is. Or at least NOT in Romania.
> The RM9200 proto board we did is a
> 175x100 mm four layer board; the PCB cost was $51. The board was
> carefully hand soldered. It's also possible to do reflow soldering
> using a toaster oven or skillet (and at least you can manually inspect
> QFP's, unlike BGA's). There are proto assembly houses that will
> assemble BGA's in small quantities, but so far I haven't found any
> with reasonable prices (e.g. $50 per BGA - OK for a prototype, but not
> for production). But for doing super small boards or advanced
> systems, BGA's are basically required.
You do live in US, right ? :) When it comes to the possibilities you
have for prototyping small quantities of PCBs, I truly envy US.
> SparkFun has some good tutorials on soldering here:
Good, yes. Then again, I don't see myself doing a PCB stencil to apply
the solder paste and then cooking everything in a
temperature-controlled oven, simply because I can't make a PCB
stencil, and there are no companies in RO doing this for hobbists. I'd
love to work with US (and other) companies, but then the shipping
taxes will be as high (or even higher) than the actual package cost.
Happened to me more than once, even with companies from the EU.
> I have some interest along Lua Stamp lines, but right now I'm spending
> my time (and too much money) on CANOpen hardware (servo drives,
> stepper drives, I/O, etc). But, back on topic, I hope to have some
> Lua code for CANOpen by the end of the year.
Very good! I like CAN a lot, but somehow I didn't have the chance to
work with it too much. Can't wait to see Lua doing CAN.
On topic: my patch is evolving quicker than I expected, which is good
news. It now passes all the tests in the "official" Lua test suite
(http://lua-users.org/lists/lua-l/2006-03/msg00716.html), but still
needs some serious brushing before it will be ready for publishing.
For the regular Lua, it saves about 6k of RAM on startup. If you think
that this doesn't make much difference on a desktop, you're perfectly
right :) Remember, this is intended for small/medium complexity
embedded systems. From this point on things the memory saving can only
get better, as eLua (and probably Lua for Lego NXT too) registers lots
of other modules on startup, which (at least for eLua) won't require
RAM consuming dictionaries anymore. I still think I can do better even
with regular Lua with some compromises, but I'm not 100% yet.