2011-01-02 04:27 wpwrak: looks nice, but what does that antenna graph mean? http://downloads.qi-hardware.com/people/werner/wpan/tmp/atusb-ng-s7.png 2011-01-02 04:27 what's are the fg* and ng* curves 2011-01-02 04:29 wolfspraul: naw, it actually doesn't look so nice. "fg" is the first generation of the atusb boards, "ng" the next generation. 2011-01-02 04:29 wolfspraul: as you can see, i managed to "improve" it by about -10 dB :) 2011-01-02 04:31 .. which means that "ng" isn't the last word on that design :) but first i have to verify a few simpler theories regarding possible design bugs 2011-01-02 04:33 I see. 2011-01-02 04:35 i suspect that i may have put the antenna too close to the rest of the circuit 2011-01-02 04:37 btw you said it now days .5-1 days to make one board, what is the time spent on? 2011-01-02 04:38 s/now days .5/now takes .5/ 2011-01-02 04:38 (no coffee yet :-)) 2011-01-02 04:38 mirko: great news about the rfm12 module! 2011-01-02 04:38 it's about equal parts making the pcb and soldering/testing 2011-01-02 04:39 pcb-making is as follows: 1) put a pcb in the mill (or continue using the one already there - each is currently good for ~8 atusb boards) 2011-01-02 04:41 2) install the drill bit in the mill, then use "make cng" (in atusb/cam2/) to check the position and to adjust the drill bit's heights 2011-01-02 04:41 3) "make drill" 2011-01-02 04:41 4) use "make cng" to replace the drill with an endmill. 2011-01-02 04:41 5) "make mill" 2011-01-02 04:42 6) remove the board, soak the side with the adhesive tape (used to keep the board in place in the mill) with paint remover, then pull off the tape 2011-01-02 04:44 7) make the toner transfer sheets (mark a piece of paper to indicate its position in the tray, make front/back, cut a piece of toner transfer paper to the right size, wipe with alcohol, tape to the paper, make front/back again. do this for both sides) 2011-01-02 04:44 8) scrub one side of the board with steel wool, then clean with alcohol. 2011-01-02 04:46 9) put the transfer paper with the toner side facing up, and the board with the clean copper side facing down. get a piece of adhesive tape and attach it to the board's back (facing up), then position board and tape exactly in on the transfer paper. 2011-01-02 04:47 (position and then fix, with the tape, which is a bit larger than the board) 2011-01-02 04:49 10) cut a strip of paper and tape the "sandwich" on it. fold the paper in the middle so that there's paper above and below the "sandwich". the paper is used for transport and for keeping the sticky-when-hot transfer paper from touching things. 2011-01-02 04:49 sounds like if you would make a panel, you could save time per board. but of course then you couldn't experiment different things on each board. 2011-01-02 04:49 11) heat up the laminator and send the package through it. 2011-01-02 04:51 yes, i have a pretty high rate of variations in this case. 2011-01-02 04:52 12) when the package comes out of the laminator, cut the board free (leaving the back still covered by tape) and remove the transfer paper. visually check that the traces are good. 2011-01-02 04:52 13) wash the board with water, then gently dry. fix any small defects found with an etch resist pen. 2011-01-02 04:53 14) set up the acid (HCl + H2O2) and etch the board 2011-01-02 04:54 15) wash off the acid with water. then soak the tape with paint remover and peel off the tape. 2011-01-02 04:54 16) repeat steps 7 through 15 for the other side of the board 2011-01-02 04:55 17) visually inspect the board and test for short or broken traces. remove shorts with a cutter, remember interruptions for later repair. 2011-01-02 04:56 18) cover one side of the board with flux, when "paint" solder on it, to cover/protect all the copper. 2011-01-02 04:56 19) do 18 for the other side 2011-01-02 04:56 20) done :-) 2011-01-02 04:57 ah, there's a bit more washing after 16, also with paint remover, to remove the toner. then clean the board with alcohol. 2011-01-02 04:58 i'm etching the two sides separateley in order to be able to obtain higher accuracy when positioning the toner sheets. with a bit of patience, i get what looks like about 0.1-0.2 mm. 2011-01-02 05:00 we should transfer this text into a small README file along with the sources 2011-01-02 05:00 at least we have it here now and it's archived... 2011-01-02 05:00 my previous approach, where i did both sides at the same time had a larger error between the toner sheets and even worse between board and sheets. not good enough for boards with pre-drilled holes (back then, i did the holes manually at the end, but that's getting too messy with the huge number of vias i have now) 2011-01-02 05:01 i guess i should document the process with some pictures ;-) 2011-01-02 05:01 sure, even better 2011-01-02 05:01 a looong time ago, i did this for an earlier version of the process. lemme find it ... 2011-01-02 05:05 http://www.almesberger.net/misc/led-toy/ledtoy-building-0pre9.pdf 2011-01-02 05:13 going from manual to cnc drilling was a big step forward. i had to build quite a bit of extra sw infrastructure for it (cae-tools/cameo/), but i now have much more precise via holes, i can do proper mechanical mounting holes (e.g., for the USB connector), and i don't go through quite so many broken drills anymore either :) 2011-01-02 05:15 i also found a wire that's just the size of the small drill (13.5 mil diameter). so i can put a bit of wire into the hole, and it will stay there, held by friction. before, the wires were loose and thus difficult to solder. 2011-01-02 05:16 the bottom line is that the 38 vias i have now are less of a pain than the perhaps 10 vias i had on similar boards before 2011-01-02 05:20 what still sucks are the ground zones. they quite literally suck, namely heat away from whatever it is i'm actually trying to solder. the experiments with the hot plate resulted in two devices plagued by mysterious defects, so i suspect that process still needs tweaking. for now, i went back to cold boards. (and 100% instead of 0% yield :) 2011-01-02 06:08 added some more vias that i didn't consider necessary. measurements show that this assessment was amazingly correct. hehe :) 2011-01-02 06:09 don't understand 2011-01-02 06:10 then why add them? 2011-01-02 06:10 which assessment was correct? 2011-01-02 06:26 i added them to confirm that they're really not necessary 2011-01-02 06:39 and another experiment (shorting a cap that appears in some reference designs but not in others) ... also no change. good. 2011-01-02 06:40 now the moment of truth ... what if i replace the antenna with the usual wifi version ... 2011-01-02 06:59 after disconnecting the pcb antenna, the signal drops by another 15-20 dB. good. the matrix isn't failing just yet :) 2011-01-02 07:58 [commit] David KÃ¼hling: add workaround for org-mode problem (todo: need a cleaner fix...) http://qi-hw.com/p/openwrt-packages/297b631 2011-01-02 09:23 [commit] David KÃ¼hling: New OpenWrt package for GNU Octave.Â Â Experimental/probably still broken. http://qi-hw.com/p/openwrt-packages/9aaeb46 2011-01-02 09:30 GNU Octave - cool! That was one of our early dreams of what could run on the NanoNote :-) 2011-01-02 09:33 Hello dear qi people. 2011-01-02 09:33 wolfspraul: maybe you remember... I had a "it works for me" solution for offline rss reading 2011-01-02 09:34 Finally I wrote a special purpose program, that should build fine for the nanonote, and work well there. 2011-01-02 09:34 oh nice 2011-01-02 09:34 http://vicerveza.homeunix.net/~viric/cgi-bin/offrss 2011-01-02 09:35 well, it is also in "works for me" state. But a friend started using it too. 2011-01-02 09:37 ok we should make an openwrt package for it 2011-01-02 09:37 btw, I saw this recently, not sure you know it... http://newsbeuter.org/ 2011-01-02 09:37 ah I did not know it 2011-01-02 09:38 I subscribe to lots of comic stripes :) 2011-01-02 09:38 so, not a solution for me ;) 2011-01-02 09:38 In the nanonote I prefer the approach "offrss + lynx" 2011-01-02 09:40 comic stripes? 2011-01-02 09:40 hm 2011-01-02 09:40 how does that work? in text mode? 2011-01-02 09:41 lynx respects the mailcap 2011-01-02 09:41 and can launch fbi to view pictures for example. 2011-01-02 09:42 nice 2011-01-02 09:42 well then, we should package offrss... 2011-01-02 09:42 'offrss' even downloads the images locally. 2011-01-02 09:42 thanks for sharing the link! 2011-01-02 09:42 I'd be pleased if others use it. :) 2011-01-02 09:42 I'll make a release with version number once I make it look better 2011-01-02 09:43 But for features, it's in good shape. 2011-01-02 09:43 ok good 2011-01-02 09:44 I'll try to make it work as CGI too, now. 2011-01-02 09:52 wolfspraul: wiki page: is okey for me :) 2011-01-02 10:25 [commit] David KÃ¼hling: Add gfortran compiler support to the toolchain http://qi-hw.com/p/openwrt-xburst/6efd70c 2011-01-02 10:45 once again: gforth guy? 2011-01-02 10:45 or really, anyone with a vague interest in gforth 2011-01-02 10:46 or forth 2011-01-02 10:49 you mean you are looking for someone? 2011-01-02 10:49 yeah, I found some nice forth programs not too long ago 2011-01-02 10:49 I wrote some gforth code some time ago 2011-01-02 10:49 a word editor and a spreadsheet editor 2011-01-02 10:49 pretty basic, of course 2011-01-02 10:49 I tried to read the spreadsheet editor 2011-01-02 10:50 but basic is awesome in this case imo :P 2011-01-02 10:50 and I concluded that I don't have enough interest to do anything with it 2011-01-02 10:50 :) 2011-01-02 10:50 I did tic-tac-toe 2011-01-02 10:50 because I got inspired 2011-01-02 10:52 bartbes: with computer players? 2011-01-02 10:52 heh no 2011-01-02 10:52 I got lazy 2011-01-02 10:52 I remember the xkcd poster about tic-tac-toe :) 2011-01-02 10:54 [commit] David KÃ¼hling: octave: add dependency to fortran runtime lib http://qi-hw.com/p/openwrt-packages/e013ed5 2011-01-02 10:54 [commit] David KÃ¼hling: octave: fix pager flags to work with busybox'es less http://qi-hw.com/p/openwrt-packages/5d05b1a 2011-01-02 11:02 anyone going to fosdem? 2011-01-02 11:14 zedstar: I was thinking about it. 2011-01-02 11:19 viric: same here....guess i need to decide soon 2011-01-02 11:22 My decision will be mainly affected by the price of the flight 2011-01-02 11:24 yeh.....seems like plenty of options for accomodation anyway 2011-01-02 11:24 hm I'd stay in the home of a friend 2011-01-02 11:28 if anybody goes to FOSDEM, hold the copyleft hardware flag up high! 2011-01-02 11:28 maybe on the mobile side they will all be drooling over their Android gadgets :-) 2011-01-02 11:29 wolfspraul: http://www.codon.org.uk/~mjg59/android_tablets/ did you see? 2011-01-02 11:29 (software related, not hardware, though) 2011-01-02 11:29 yes I saw it 2011-01-02 11:30 the big companies are founding more and more BSD-licensed developments 2011-01-02 11:30 sure 2011-01-02 11:30 learn from Apple :-) 2011-01-02 11:30 as a way to get more and more closed hardware 2011-01-02 11:30 and software 2011-01-02 11:30 of course 2011-01-02 11:30 this is all squarely heading in the direction of a GPL sandbox 2011-01-02 11:31 so the Linux kernel can do scheduling, memory management, and USB drivers :-) 2011-01-02 11:31 exactly. 2011-01-02 11:31 but it's virtualized and all the 'real' investment is happening on the proprietary side 2011-01-02 11:31 Everybody wants linux only for the drivers 2011-01-02 11:31 of course 2011-01-02 11:31 what's wrong with this strategy? 2011-01-02 11:31 that this is the only GPL piece they will accept 2011-01-02 11:32 in a few years, the entire GPL sandbox will be virtualized 2011-01-02 11:32 then the problem is contained 2011-01-02 11:32 uh? 2011-01-02 11:32 I don't follow. 2011-01-02 11:32 Maybe I don't understand enough what you mean by 'gpl sandbox' 2011-01-02 11:33 a virtualized guest machine instance, for Linux 2011-01-02 11:34 I don't follow :) 2011-01-02 11:34 hmm. sorry. What is the question? 2011-01-02 11:34 so you imagine people running Windows, then a virtualisation software that will run Linux (kernel-only), and inside Linux what? 2011-01-02 11:35 or you mean Linux as the host OS? 2011-01-02 11:35 Windows? no I talk about the embedded world, let's say smartphones/tablets. 2011-01-02 11:35 well, I meant.. you see Linux as guest os , or host os? 2011-01-02 11:35 no, the software running directly on the hardware will be a proprietary kernel and features/stacks 2011-01-02 11:35 and then there will be a virtualized Linux instance 2011-01-02 11:35 which I ironically call 'GPL sandbox' 2011-01-02 11:36 ahh. 2011-01-02 11:36 so Linux will know less and less about the hardware. 2011-01-02 11:36 and that propietary kernel will decide what guest OS it allows 2011-01-02 11:37 oh it will allow and use Linux, why not 2011-01-02 11:37 it could allow Linux signed by someone in particular 2011-01-02 11:37 it's a nice scheduler and memory manager, and has a bunch of nice drivers too. plus - all free :-) 2011-01-02 11:38 http://www.pcworld.com/businesscenter/article/205231/arm_processor_ups_the_ante_for_mobile_computing_power.html 2011-01-02 11:38 anyway we see where it goes 2011-01-02 11:38 do we? 2011-01-02 11:38 conspiracy theories are not popular, 'tin foil hat' etc. 2011-01-02 11:38 yes sure 2011-01-02 11:38 :-) 2011-01-02 11:38 hopefully we can make some really cool copyleft hardware by then 2011-01-02 11:38 that's all that matters 2011-01-02 11:38 "With the Cortex A15 processor, ARM is introducing new technologies that enable hardware virtualization" 2011-01-02 11:39 ahh. 2011-01-02 11:39 I'm so happy the Ben NanoNote has an Android immunization, in the form of 32 MB memory. 2011-01-02 11:39 that shot was very effective :-) 2011-01-02 11:39 wolfspraul: also the Loongson3 has x86 virtualisation support 2011-01-02 11:39 nobody is crazy enough to try to port Android to NanoNote 2011-01-02 11:40 wolfspraul: ah, I could not imagine one single advantadge of 32MB of RAM :) 2011-01-02 11:43 yeah, but how about that one? 2011-01-02 11:43 Android immunization 2011-01-02 11:43 tough luck for the drois 2011-01-02 11:43 droids 2011-01-02 11:44 it was not on purpose, but seriously, it does have that effect 2011-01-02 11:44 I'm sure if we would have 128 MB memory, someone would have tried already 2011-01-02 11:44 did it happen with the freerunner? 2011-01-02 11:44 even though it's nearly impossible to make a good Android system with 128 mb, you need 256 and more today, 512, etc. 2011-01-02 11:44 shooting up 2011-01-02 11:44 so the NanoNote is safe :-) 2011-01-02 11:45 well, lack of wireless also contributes ;) 2011-01-02 11:45 [freerunner] hard to say, in hindsight vision is always 20/20 2011-01-02 11:45 I focus on the Ben now. 2011-01-02 11:45 good! 2011-01-02 11:45 thank you very much 2011-01-02 11:45 lack of wireless - let's see when Werner's magic boards are working :-) 2011-01-02 11:46 and mirko made some headway into controlling power switches remotely using HopeRF modules... 2011-01-02 11:46 that looks very good. 2011-01-02 11:46 aren't there, btw, any minisd to microsd adapters, to be able to use a minisd wifi card? 2011-01-02 11:47 we've made some adapters from full size down to our size 2011-01-02 11:47 but they are not meant for regular use, too breakable 2011-01-02 11:47 I think I've made like 10 or 20 of them, and gave away. 2011-01-02 11:47 isn't anyone producing those? 2011-01-02 11:48 I doubt it. 2011-01-02 11:48 ah well, wait. 2011-01-02 11:48 I remember googling a while back, and did actually find some pictures. 2011-01-02 11:48 because they could go very cheap 2011-01-02 11:48 sure 2011-01-02 11:48 I remember finding some online shops listing them, maybe originating from Japan. 2011-01-02 11:48 but in any event, those are extremely low volume products 2011-01-02 11:48 ah. 2011-01-02 11:48 well, I don't imagine a mass public for those. 2011-01-02 12:12 http://downloads.qi-hardware.com/people/werner/wpan/tmp/atusb-s8.png 2011-01-02 12:12 new antenna? 2011-01-02 12:13 ng2 through ng2b are the basic design, with a few small (and ultimately irrelevant) changes 2011-01-02 12:13 ng2c is with the antenna cut off 2011-01-02 12:13 ng2d is with an external wifi antenna 2011-01-02 12:13 2d-ref-2 looks good, no? 2011-01-02 12:14 the different ng2d runs correspond to different positions of the antenna 2011-01-02 12:14 ref-2 looks very similar to what i got with the first atusb design: http://downloads.qi-hardware.com/people/werner/wpan/tmp/atusb-ng-s7.png 2011-01-02 12:15 ironically, in that one i did almost everything the way they don't tell you to ;-) 2011-01-02 12:16 ok, so for your own pcb antenna, performance is ca. 10dB worse than the best wifi antenna, with particular problems around 2450 mhz? 2011-01-02 12:16 discrete balun (instead of integrated), no ground plane on top of pcb next to the antenne (only below), feed line is not impedance-matched 2011-01-02 12:16 is this a correct interpretation of the graph? 2011-01-02 12:16 yes, in that design 2011-01-02 12:17 the only time I see a bump around 2450 even similar to what you consistently see with your antenna is the 2d-ref-0 2011-01-02 12:17 the bump is at 2455 there and less pronounced, but still 2011-01-02 12:18 does that give you any clue as to why you consistently have this 2450 problem? 2011-01-02 12:19 i think the ones in ng2d are mainly imperfections of my test setup (reflections and such) 2011-01-02 12:19 the deep drop at 2450 looks like a real problem, though. well, i'll see in a bit. now i'm moving this antenna around, too 2011-01-02 12:20 oh, nice. plugged into a laptop, it gets better :) 2011-01-02 12:21 the fun thing with rf is that i'm never quite sure if i'm not just chasing my own tail ;-) 2011-01-02 12:22 btw I am cleaning up the stdout/stderr and exit code handling in my eeschema and pcbnew patches 2011-01-02 12:22 the laptop is an oqo, which has a full-metal case. best ground you could possible get in a mobile device ;-) 2011-01-02 12:22 it's not good right now :-) I hope to commit this in an hour or two 2011-01-02 12:22 great ! the exit code can be a bit confusing. good to have it gone. 2011-01-02 12:23 yes 2011-01-02 12:23 also stdout/stderr is a mess 2011-01-02 12:23 rome wasn't built in a day, sorry about that ;-) 2011-01-02 12:23 didn't notice stdout/stderr :) 2011-01-02 12:23 it becomes more apparent in the schhist scripts where you do some funky stuff with stdout/stderr 2011-01-02 12:24 aah, i see 2011-01-02 12:59 [commit] Wolfgang Spraul: updated gitsch2ps to new eeschema --plot syntax http://qi-hw.com/p/eda-tools/0f4e2be 2011-01-02 12:59 [commit] Wolfgang Spraul: fixed stdout/stderr and exit code, removed old eeschema --plot http://qi-hw.com/p/eda-tools/7f9de6f 2011-01-02 13:02 and he we have an atusb (ng) board in the oqo. for comparison, -0 is with the board on a cable (like in all previous tests). then i put it into the oqo and moved it around a bit 2011-01-02 13:02 http://downloads.qi-hardware.com/people/werner/wpan/tmp/atusb-s9.png 2011-01-02 13:02 s/he/here/ 2011-01-02 13:09 interesting 2011-01-02 13:09 ref-1 seems best 2011-01-02 13:09 with "-0 on a cable" you mean some sort of usb extender cable? 2011-01-02 13:22 yes, a usb-a to usb-a cable 2011-01-02 13:46 wolfspraul: here's the receiver, the usrp with a wifi antenna: http://downloads.qi-hardware.com/people/werner/wpan/rflab-rx-refant.jpg 2011-01-02 13:47 wolfspraul: and here are the senders: http://downloads.qi-hardware.com/people/werner/wpan/rflab-atusb.jpg 2011-01-02 13:48 wpwrak, that looks like something you'd use for tortures ;) 2011-01-02 13:54 nice 2011-01-02 14:04 kewl 2011-01-02 14:07 nice to see a blue sky! 2011-01-02 14:16 [commit] David KÃ¼hling: octave: fix various shared library rpath problems http://qi-hw.com/p/openwrt-packages/880bca2 2011-01-02 14:19 zedstar: you like blue skies ? here's a bit of the view from my office: http://downloads.qi-hardware.com/people/werner/tmp/office.jpg 2011-01-02 14:20 zedstar: alas, my camera doesn't have a good wide-angle, so i can't get it all in one image (and i'm too lazy to stitch them together) 2011-01-02 14:22 wpwrak: im jealous! 2011-01-02 14:24 should i mention that we have a nice 28 C at the moment ? 2011-01-02 14:25 growls 2011-01-02 14:28 wolfspraul: i;m bringing you three bens closer to selling out :) need some more devices for experimenting 2011-01-02 14:29 eh, fantastic! 2011-01-02 14:30 ah, you guys created an account for me already :) good that you have a password retrieval feature :) 2011-01-02 14:31 I plan to remove account creation on the new online shop 2011-01-02 14:32 it's a mixed-blessing kind of feature. can be convenient of you buy a lot from the same place, to avoid problems with typos. 2011-01-02 14:32 on the other hand, mandatory account creation is annoying for one-time customers. but you have both options, so that seems reasonable. 2011-01-02 14:34 I think not collecting and storing customer data is a feature. Handle the transaction, then purge all unnecessary data, handle the warranty stuff in an anonymous way. 2011-01-02 14:34 together with making every unique ID on the device both documented and removable that's going to be a challenge :-) 2011-01-02 14:46 it's a risk/liability reduction feature at least :) 2011-01-02 14:54 let's see how long the toys take. and tomorrow, the same with digi-key :) 2011-01-02 14:59 thanks a lot for the order! 2011-01-02 15:00 we have to work together to beat ron's forecast ! ;-) 2011-01-02 15:00 yeah, ron... 2011-01-02 15:00 now he tries to poke into our Milkymist fun 2011-01-02 15:00 he's good. knows exactly the right questions ;-) 2011-01-02 15:01 yes and no. wrong perspective. he should think about free software first. 2011-01-02 15:01 sure if you leave that out, his questions are spot on. 2011-01-02 15:01 say if we were Apple. 2011-01-02 15:02 but it's good he's around, keeps me grounded 2011-01-02 15:02 he should simply _do_ stuff instead of gawking and asking trivial questions that i've heard a thousand times 2011-01-02 15:02 sure, he will never :-) 2011-01-02 15:03 well, the power consumption of that fpga is likely to be something to worry about. 2011-01-02 15:04 (in due time :) 2011-01-02 15:04 yeah 2011-01-02 15:04 :-) 2011-01-02 16:05 [commit] Werner Almesberger: atusb.brd: increased RF ground zone http://qi-hw.com/p/ben-wpan/fd76be6 2011-01-02 16:08 newsbeuter is nice i use it, kind of ram eating unless you limit the number of items 2011-01-02 19:58 mupdf on milkymist: http://www.milkymist.org/fn_mupdf.jpg 2011-01-02 19:58 wpwrak: you see i'm using software libraries when they're good. I didn't write my own pdf rendering lib :) 2011-01-02 20:04 hehe ;-) 2011-01-02 20:06 actually, flickernoise links against ~12 libraries that I didn't write for the most part... 2011-01-02 20:07 fortunately there's something else than GNU/Linux and X.org :) 2011-01-02 20:08 ah, regarding LLHDL, someone (kristianpaul ?) mentioned that there's still one non-free tool in the path, place and route, i think. is this also among the things you plan to replace ? (being an fpga ignoramus, i don't know the whole synthesis process) 2011-01-02 20:09 btw it's pretty amazing that this 80MHz RISC softcore with mupdf is about as slow (or fast?) than kde's okular on my 2.5GHz superscalar dual core 2011-01-02 20:09 (x.org) well, you mentioned kdrive as a more palatable alternative, didn't you ? you'll get there :) 2011-01-02 20:10 (as slow) ah, i've been wondering about the performance and whether there would be any meaningful benchmarks for PDFs 2011-01-02 20:11 well even without any benchmark you can say KDE/X11 is bloated :) 2011-01-02 20:11 (as slow) would be nice to be able to have some data to compare MM1 performance with systems "people know". well, as long as that data looks good. else fix first, publish later ;-) 2011-01-02 20:12 it's some 20% faster than microblaze at the same clock frequency 2011-01-02 20:12 that for the CPU power only 2011-01-02 20:12 what worries me about things like KDE is the gazillion of helper threads and things they spawn before even beginning to do anything 2011-01-02 20:12 when rendering, most of the computationally intensive stuff is done with hardware acceleration on the fpga 2011-01-02 20:13 so also the PDF renderer benefits from the hw acceleration ? 2011-01-02 20:13 no, it's software only 2011-01-02 20:13 all the GUI is entirely software 2011-01-02 20:14 I wanted something simple :) 2011-01-02 20:14 though I could still implement hardware accelerated blitting without much trouble 2011-01-02 20:14 hey nice pic :_) 2011-01-02 20:15 accelerating pdf decoding in hw would mean a lot of work 2011-01-02 20:15 blitting may be useful, particular if your GUI stays away from compositing :) 2011-01-02 20:15 I wouldn't do that 2011-01-02 20:16 that's the sort of work you'd only do for benchmarks ;-) have a little dhrystone engine :) 2011-01-02 20:17 (hw aceleration) i wonder if rtems people tought on that when developing it... 2011-01-02 20:18 no, but contrary to linux, rtems is easy to hack to your needs 2011-01-02 20:18 surelly :_) 2011-01-02 20:19 give it time to get fatter and it'll be just as hard ;-) you'd be amazed how easy it was to get major changes into linux in the old days 2011-01-02 20:20 get fat is an unfair comparison as when gas expands 2011-01-02 20:21 wpwrak: i tought linux got fat mainlly because drivers.. 2011-01-02 20:22 wpwrak: but even tought linux can run on my linksys router, thats neat :-) 2011-01-02 20:22 drivers, architectures, sub-architectures, layers of abstraction, exotic protocols, it's all there 2011-01-02 20:23 oh dear.. 2011-01-02 20:24 also, simple implementations have been replaced by more efficient but more complex ones 2011-01-02 20:24 think the block I/O subsystem, memory management, SMP, NUMA, ... 2011-01-02 20:25 so simple is not always efficient at all? 2011-01-02 20:25 the linux kernel is actually still remarkably clean and simple if you consider all the things it can do 2011-01-02 20:25 but all that is actually because hardware require it? 2011-01-02 20:26 new complex and big hardware everyday.. 2011-01-02 20:26 so linux should run on it ! 2011-01-02 20:26 (simple/efficient) well, think of RCU. that's a non-trival approach that is much more efficient than the traditional solutions for this kind of locking problem 2011-01-02 20:26 what we do to run better... 2011-01-02 20:26 ah yes lets implement all this... you already mentioned 2011-01-02 20:27 (rcu) and they built upon the basic concept, making it even more efficient. but yes, you lose simplicity this way. now you need to read a few research papers before you understand the concept. 2011-01-02 20:27 of course 2011-01-02 20:28 (linux kernel is actually still remarkably clean and simple if you consider all the things it can do) i agree 2011-01-02 20:28 i cant complain yet for soemthing i cant do :-) 2011-01-02 20:28 and then, we have linux run on anything from that linksys of yours, to the whole world of pcs, to some huge mainframes. all with the same kernel. in many cases using exactly the same code. 2011-01-02 20:29 this is a unique archievement. nobody else managed that kind of scalability. 2011-01-02 20:29 just Milkymist One missing ;-) 2011-01-02 20:29 in a proper not blamed way 2011-01-02 20:29 yeah. MM1 is somewhere in the middle :) 2011-01-02 20:31 ah the mmu thing :-) 2011-01-02 20:32 yeah, the nommu has to go 2011-01-02 20:35 then get the arch properly into mainline. put X on top. and then it's just optimization beyond that ;-) 2011-01-02 20:35 maybe even the wayward guys will eventually make something useable, who knows 2011-01-02 20:37 learn new word today *wayward* 2011-01-02 20:38 damn, how usefull dual ported ram are 2011-01-02 20:38 well, they call it "wayland". but i like "wayward" better ;-) 2011-01-02 20:39 not intetionally related with some capricious 2011-01-02 20:40 hmm i remenber from a funny talk at 27c3 (desktop on linux), that wayland wanted to control the audio stuff in a more low level way.. 2011-01-02 20:40 anyway.. lets see what Linux thinks about :-) 2011-01-02 20:41 ah, 27c3 ... what was that thing about making pcbs with a modified ink printer ? did anyone have a look at that ? 2011-01-02 20:41 i did 2011-01-02 20:42 did it seem reasonable ? 2011-01-02 20:42 looks interesting concept for me, but LOT of profesional work need to be if that thing wants to get work 2011-01-02 20:42 surelly the guy need more poeple involved 2011-01-02 20:43 reasonable not so much now 2011-01-02 20:43 ah, not just "buy printer X, toss away the ink and replace it with acid Y, and you're all set" then 2011-01-02 20:44 from why understand its printer head self disamble after some prints 2011-01-02 20:44 hehe ;-) 2011-01-02 20:44 when he fix that i'll take a look again 2011-01-02 20:44 i was wondering how he'd keep the acid from eating the head :) 2011-01-02 20:45 actually what he metioned is been introduced in reprap project too 2011-01-02 20:45 is clear that floss injects are next step 2011-01-02 20:45 what acid does he print with ? 2011-01-02 20:45 is not acid 2011-01-02 20:45 is soemthing avoid acid actually 2011-01-02 20:45 oh, i thought he was etching the board directly 2011-01-02 20:45 you need a second step later 2011-01-02 20:45 mee too 2011-01-02 20:45 but no 2011-01-02 20:46 aah. ! so he's printing acid resist and then etches. okay. that should be easier. 2011-01-02 20:46 some results he show looked pretty well 2011-01-02 20:47 but still too hackish appliance 2011-01-02 20:47 (direct etching) i was wondering what kind of witchbrew he'd use. it would have to be extremely aggressive for direct application. 2011-01-02 20:48 my first tought was he finally found the mix to do cheap conductive wires 2011-01-02 20:48 but nah.. 2011-01-02 20:48 cheap conductive wires ? have you checked silver prices lately ? ;-) 2011-01-02 20:49 s/wires/printed wires 2011-01-02 20:49 conductive ink is expensive 2011-01-02 22:04 adamw_, DocScrutinizer: Q: if i have a full-speed (11 Mbps) USB interface and i want to add a TVS, what would you consider the highest capacitance for the TVS that's still acceptable ? right now, i use 100 pF. 2011-01-02 22:05 wpwrak, second 2011-01-02 22:07 ah, 50 pF, it seems. usb 2.0, page 130, figure 7-9. 2011-01-02 22:08 good. i was planning to go to 33 pF. so that should be fine then. 2011-01-02 22:08 no need to get any fancy < 1 pF parts :) 2011-01-02 22:09 you could also check http://www.littelfuse.com/data/en/Data_Sheets/Littelfuse_MLV_MHS.pdf 2011-01-02 22:10 page 2, Typical capacitance at 1MHz (1Vp-p) 2011-01-02 22:10 yeah, i've seen that you're using them for xue. i'm a little horrified by the clamping voltage. 42 V ! 2011-01-02 22:12 hm...yeah...but now you already checked usb 2.0 page 130. 2011-01-02 22:12 so you can just directly use it for sure. 2011-01-02 22:13 i didn't involve in Xue then, so don't know what value they used. 2011-01-02 22:14 i could only suggest that you use our parts as possible if you review that value is fine to you. :) 2011-01-02 22:16 i have my eyes set on the 445-2559-1-ND from TDK. 5.5 Vdc working voltage, clamps at 19 V, USD 0.044 for a 10kU reel 2011-01-02 22:17 please also check to this good article : http://www.intel.com/technology/usb/download/usb2dg_r1_0.pdf 2011-01-02 22:18 ah, the one in xue clamps at 135 V. 42 V is the operating voltage. seems very high to me. 2011-01-02 22:21 correct, 2011-01-02 22:22 hmm, high-speed. things get a little nasty there for sure. "A device that has been tested successfully is based on spark gap technology." 2011-01-02 22:22 you don't need to follow Xue, just pick a reasonable value! 2011-01-02 22:23 agreed...so the question is that how we estimate a spark gap? 2011-01-02 22:23 in advance? well...in practically you should can estimate it first. 2011-01-02 22:24 yeah.Â Â 445-2559-1-ND looks friendly. plan B would be the stackpole ESD02A5V5R25VCT-ND. about twice as expensive, but only 0.2 pF. clamps at 25 V (with a slightly more expensive 17 V variant available as well) 2011-01-02 22:24 assume first 2011-01-02 22:25 (spark gap) naw, that would be a chip. with built-in spark gap. F1320CT-ND 2011-01-02 22:25 carefully when you read that voltage at clamping value...always to see the real curve they plotted in datasheet to pick up. 2011-01-02 22:25 or, better: F2594CT-ND 2011-01-02 22:31 curves - where available - look reasonable. don't show things too clearly, though. 2011-01-02 22:31 page 6 of 445-2559-1-ND, page 8 for comparison of various element. 2011-01-02 22:33 are you planning that we need to do ESD test? or just choose a part which can suffer from ESD design-in. 2011-01-02 22:33 just designing. the c8051f3xx chips need external ESD protection for USB (at least that's what the data sheet says) 2011-01-02 22:34 hmm...ok 2011-01-02 22:35