#qi-hardware IRC log for Wednesday, 2010-12-29

DocScrutinizerthey suggest a 4.7uF on VDD, you got 2uF00:00
DocScrutinizeractually 2.100:01
DocScrutinizerwhat's with AT86 [12] and [13] DVDD?00:01
wpwrakyup :) they put all sorts of values there. e.g., page 32.00:01
wpwrakthe at86rf230 has internal 1.8 V regulators for DVDD and AVDD00:03
wpwrakC11 and C12 are their bypass caps00:03
DocScrutinizerMHM, via DEVDD00:03
DocScrutinizerand EVDD. I see00:04
DocScrutinizer(should've checked the datasheet of AT86...)00:05
DocScrutinizerwpwrak: check fig1.6 - you could hook up a storage scopte to nRST and see if it caches any 0 level. AIUI nRST also is an output. You could distinguish between VDD created resets and clock-failure related ones00:13
DocScrutinizerwpwrak: also what's the state you set MCD to? (missing clock detector enable)00:14
wpwrak(MCD) lemme see ...00:26
wpwraki disbale everything but power-on/VDD monitor00:27
DocScrutinizerVDD is allowed to be between 3.0V and 3.6V00:27
wpwrak(that is, if i make it into the boot loader)00:28
DocScrutinizer(<wpwrak> i don't like the 5 V on the VDD rail at all.) :-o00:28
wpwraki wonder if i have some weird solder bridge somewhere that i keep on overlooking00:29
wpwrakthe layout is quite dense. i've gradually relaxed it a bit since. maybe i should just make a new board and see if things get better.00:29
wpwrakwith these boards, i also tried a hot plate for the first time, to help with soldering at/near large ground zones. http://downloads.qi-hardware.com/people/werner/tmp/hotplate.jpg00:30
wpwraki wonder if the changed thermal stress pattern has done something00:31
wpwrakhow far did you see what i wrote ?00:31
DocScrutinizer[2010-12-29 06:29:35] <wpwrak> the layout00:32
DocScrutinizerbetween REGIN and VDD maybe?00:32
wpwrakwith these boards, i also tried a hot plate for the first time, to help with soldering at/near large ground zones. http://downloads.qi-hardware.com/people/werner/tmp/hotplate.jpg00:33
wpwraki wonder if the changed thermal stress pattern has done something00:33
DocScrutinizerI still wonder if you meant what you wrote00:33
wpwrak(vdd - regin/vbus short) that's of course what i tested first :)00:34
DocScrutinizerVDD is allowed to be between 3.0V and 3.6V00:34
wpwrak(what i meant) why ?00:34
DocScrutinizer(<wpwrak> i don't like the 5 V on the VDD rail at all.) :-o00:34
wpwraki have two boards. board #0 has 3.577 V on VDD. on board #1, VDD is roughly at VBUS (~5 V)00:35
DocScrutinizernow that's a massive defect00:35
wpwrakboard #0 doesn't even flash, so i've written that one off already00:35
wpwrakboard #1 developed the 5 V issue recently. when i first experimented with it, it didn't have it - just the spontaneous resets.00:36
DocScrutinizerThe voltage regulator is enabled on reset. When the device is self-powered from a 3V supply net, the reg-00:36
DocScrutinizerulator may be disabled in order to save power. Important Note: If the voltage at the regulator input00:36
DocScrutinizer(REGIN) is greater than the Core Supply Voltage (VDD), the voltage regulator should not be dis-00:36
DocScrutinizerabled. Otherwise, permanent damage to the device may occur.00:36
wpwrakthen, when preparing for adding the reset pull-up, i first wanted to check if the reset pattern repeats (varies between all the time to once every 10-30 minutes). there, the board didn't respond normally. so i checked and found VDD all wrong.00:38
wpwraki don't deliberately disable the regulator :)00:39
wpwrakof course, with the chip acting all weird, there's no telling what may happen ...00:39
DocScrutinizerOutput Voltage Output Current = 1 to 100 mA 3.0 3.3 3.6 V00:39
DocScrutinizer5V VDD is a sufficient condition to declare the device dead00:43
DocScrutinizerI'd not bother about reason for it resetting00:43
wpwrakyeah. there's no telling what damage this does.00:44
wpwrakadded 4k7 pull-up to board #0 (the one that had trouble even flashing). didn't help. actually seems a little worse - no response at all instead of badly garbled reponses. well, who knows what is wrong with this one anyway.01:26
qi-bot[commit] Werner Almesberger: atusb.brd: increased zone clearance from 8 mil to 10 mil, for solderability http://qi-hw.com/p/ben-wpan/ed591cf01:35
qi-bot[commit] Werner Almesberger: atusb.brd: added via from nRST/C2CK, to allow for addition of pull-up http://qi-hw.com/p/ben-wpan/7514fa801:35
wpwrakkristianpaul: i think the MM1 workshop is today from 13-17h berlin time : http://events.ccc.de/congress/2010/wiki/Workshops01:39
wpwrakkristianpaul: he's probably frantically trying to debug the camera. at least i'm not the only one with gremlins in his circuit ;-)01:40
xiangfususchman: hi05:39
qi-bot[commit] Xiangfu Liu: gmenu2x: add --login to ash and bash http://qi-hw.com/p/openwrt-packages/0529b7d05:39
suschmanhello wolfang05:40
kristianpaulwpwrak: (m1 workshop) so i was confused, hmm yes yday was fpga intro workshop (warm-up)08:20
wpwrakkristianpaul: and today those who yesterday happily thought they knew everything are confronted with the harsh truth of how much they still don't know ;-)08:25
wpwrakah, sebastien is here. so let me rephrase this: [...] harsh truth of how much still separates them from greatness ;-)08:30
wpwrakkristianpaul: btw, pcb making update: if you mix 3x% HCl with 3x% H2O2, the acid rips the copper away within about half a minute. the reaction is powerful enough that the acid starts to boil. very impressive, although a bit scary :)08:31
kristianpaulboil? wow08:32
kristianpaulscary indeed, thanks for the advice08:33
wpwrakkristianpaul: i tried this with a 10x15 cm board. my usual boards are much smaller, perhaps 2x3 cm. the large board was single-sided, which is probably a good thing given the intensity of the reaction :) so, 12.5 times the surface, 12.5 times the energy ...08:34
kristianpaulDit it may etch the tonner part if let it a bit more time "boiling"?08:38
wpwrakthe board had two damaged traces. but i don't know if this was caused by the strong acid or if there was some other problem. (i did the thing in a bit of a hurry)08:40
wpwrakthis was the board in http://projects.qi-hardware.com/index.php/p/wernermisc/source/tree/master/f10/08:42
wpwraka very coarse design08:42
kristianpaulWhat are those swiches for?08:46
wpwrakjust to pass power (up to 3 A, voltage as desired). the board connects to a lab supply on one end and a ribbon cable with up to 10 pairs of 22 R on the other. the idea is to launch fireworks with it. alas, it didn't work for some reason, although it behaved well in tests. need to check. it may see action on the 31st again :)08:49
wejpi've just release a new version of the Gmu Music Player: http://wejp.k.vu/gmu/gmu-0-7-2_released11:08
zedstaranyone configured one of the web browsers to trigger nupdf? what is the best text browser to try?12:41
larschm, ok, now i have to find out where he ping timeouted...12:57
qi-bot[commit] Andres Calderon: bq24070 added to BOOKSHELF http://qi-hw.com/p/xue/064b39813:41
qi-bot[commit] Andres Calderon: partial psu placement http://qi-hw.com/p/xue/b181d9d13:41
wpwrakandres-calderon: soon, we'll need to split the schematics history into several pages :-)14:48
wpwrakandres-calderon: by the way, regarding 0402, 0603, and such: the footprints in kicad-libs are designed for pick and place machines. if you envision manual soldering/rework to be a common occurrence, you may be interested in the 0402-M, 0603-M, etc., variants, which are 0.1 mm longer than the regular footprints.14:55
wpwrak(the regular 0402, 0603, etc., can be soldered by hand, but it's not very convenient. 0402-M, etc., are much easier.)14:56
wpwrakunfortunately, the length change between xxxx and xxxx-M also changes the pad centers. so you can't just replace one with the other in an existing layout.14:58
andres-calderonwpwrak:  mmm, interesting, may  be too late to change...15:24
wpwrakandres-calderon: also depends on whether it would actually be useful :)15:31
wpwrakandres-calderon: in my case, easy soldering is quite important. in your case, probably less15:31
DocScrutinizerwpwrak: for non-commercial sparkoff 22R aren't really good. I frequently used those small flash bulbs filled with oxygen and magnesium wool - usually blueish. they get so damn hot they ignite blackpowder easily15:32
wpwrakah yes, they should be good too. only .. where would you find these in this century ? ;-)15:34
DocScrutinizerwpwrak: I'd think one of those flash bulbs taped to a fuse and maybe even wrapped with tin foil, should work nicely15:34
DocScrutinizerwpwrak: (find) good question15:35
wpwrakin my tests, the 22 R ignited things reliably. it was only in the non-test use that they failed. (naturally - what would be the point in alerting me to any problems before ?)15:36
wpwrakof course, maybe it was something else that broke. i didn't examine the thing yet.15:36
wpwrakthe crumpled yellowish box suggests that they may not be the latest 2010 model ;-)15:38
wpwrakyeah, i used them too. many years ago ... :)15:38
wpwraknice. now in argentina ? :)15:39
DocScrutinizeryou need to use argentinean ebaeh for that :-D15:40
wpwrakbesides, they're quite big. the resistors are a LOT smaller. many of the firework items are smallish, too. it's not like we'd be firing a Saturn V here15:40
kristianpaulwpwrak: you can use nichrome15:41
wpwrakwe have that, "mercadolibre" :)15:41
kristianpaulyup :)15:41
wpwrakkristianpaul: nichrome ... just plain wire ? i tried that too, steel wire. works, but takes forever to heat up. and it's bulky.15:42
wpwrakone of the goals is quite specifically not to tie some heavy weight to the rockets that may jerk them off course ;-)15:43
kristianpaulyou can attach some nichrmoe/resistor  wire and some match (aka fosforo)15:51
wpwraknaw, a pair of resistors will burn nicely if treated properly :)15:53
wpwrakcomplexity is the enemy of a reliable design :)15:53
kristianpaulhow fast you need the resistor to ge ignited?15:54
wpwraki usually aim for 2-5 s15:54
kristianpaulare you  using just DC?15:57
wpwrakfor things that are difficult to ignite, flares and such, i used a sparkler as a first stage. they burn with a lot of heat15:57
wpwrakkristianpaul: (dc) yes17:32
Jay7kristianpaul: I've uploaded kexecboot v0.6-pre screenshot here http://www.kexecboot.org/about:start?&#kexecboot_v0618:07
wpwraklekernel_: hey, how did the workshop go ?23:29
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