#qi-hardware IRC log for Monday, 2012-03-05

whitequarkwpwrak: err... headless chicken? wat?00:17
whitequarkoh shi~~ I turned a module on without antenna soldered to it00:18
whitequarkseriously I need some sleep :/00:18
wpwrakwhitequark: (chicken) see the wings in the NORAD logo ? do you see a head, too ?00:19
whitequarkahhh, got it. funny!00:20
rz2kwhitequark: srsly dude, being up more thatn 14 hours is pure masochism.00:37
wpwrakrz2k: some would consider it a good beginning :)00:45
whitequarkDocScrutinizer51: hmm, attached the second module00:53
DocScrutinizer51whitequark: my PC has barfed up, about to reboot00:54
whitequarkoh, sure00:54
whitequarkDocScrutinizer: got your PC fixed?01:07
whitequarkok. so, I connected the second module, they both seem to work01:07
whitequark... and they ofcourse have slightly different internal clock frequency, which drives me crazy as the leds are a bit out of sync :/01:07
DocScrutinizernow for some suspend of my wetware, in 6 hours I'll enjoy a 3 day code quality training by ENEA01:08
whitequarkah ok, tomorrow then01:08
whitequark... code quality training?..01:08
whitequarklike "don't put all code in your main()"?01:08
Action: whitequark always thought that you get to write better code by not being an ignorant fuck rather than attending any trainings. still...01:09
whitequarkewww. according to my scope, that module just got 8V+ ripple into the power source01:12
qi-bot[commit] Xiangfu Liu: cgminer: most patches merged to upstream (master) http://qi-hw.com/p/openwrt-packages/9feb48202:19
qi-bot[commit] Xiangfu Liu: icarus-miner: remove outdata package (master) http://qi-hw.com/p/openwrt-packages/4c4746505:42
DocScrutinizerwhitequark: yep, something like that05:56
DocScrutinizer51friggin spam11:15
wolfspraulJon is just excited about this hyper-integrated little computer :-)11:51
wolfspraulsupported well by openwrt11:51
rohwell.. nothing really new or special ;)11:53
wolfspraulI wouldn't agree. it's a full computer with case and wifi and antenna for 16 USD.11:54
larscDocScrutinizer51: /ignore qi-bot11:55
wolfsprauland usb 2.0 host11:55
wolfspraulbut it's not open hardware, for sure11:55
viricwhat computer?11:55
viric16USD? what children mounted it? :)11:55
wolfspraula router, TL-WR703N (risking more spam :-))11:56
rejonviric, its ok, it was part of a conversation11:57
viricwhat conversation?11:58
whitequarkwolfspraul: define "full computer"12:01
whitequarkis atmega8 a "full computer"? is stm32f103rb? it has usbhost too.12:01
whitequarkand 32k of ram. more than Apple II12:02
whitequarkjust a cheap little router on stupid mips12:02
rohwolfspraul: yes. but that still isnt something special. most tp-link wifi routers and aps are in that pricerange if you buy more than single digit volumes12:03
wolfspraulI'm not here to defend tp-link or this router12:03
wolfspraulif you don't like it, please ignore it :-)12:04
wolfspraulit's not even open hardware12:04
rejonor better, get nanonote and milkymist up to compete with the tplink routers :)12:04
wolfspraulmaybe I can include a 703n as a wifi-gateway for m1 though, but I shall work on that silently :-)12:04
wolfspraulto bring out the beauty of m1 *today* :-)12:04
rohsure. i also dont want to talk it down. i use tp-link atheros chipset based devices myself. but its nothing special per se. neither the price nor its features12:05
whitequarksrsly, usbhost and wi-fi are just readymade ip cores with a little bit of external components, and a readymade linux driver12:05
Action: whitequark uses tplink too, fwiw12:05
whitequarkDocScrutinizer51: I assembled your coupling circuit, and it, er, works very bad13:23
whitequark(through it's probably because I screwed something up)13:23
whitequarkthere is a LOT of noise which comes from somewhere, and has a peak on 875Hz13:25
whitequarkaccording to fft13:25
whitequarksimple: the gnd was broken in audio cable I used.13:32
whitequarkDocScrutinizer51: yeah, works fine14:07
whitequarkbut I removed a potentiometer across mic lines; the sound is better without it14:08
whitequark(the circuit is http://rghost.ru/36815801.view)14:08
DocScrutinizer51OMFG, that training will kill me, at wednesday the latest16:05
whitequarkwhat's with it?16:06
DocScrutinizer51ENEA code quality16:06
DocScrutinizer51about all related to C and C++16:07
DocScrutinizer51starting from pre/post-increment to communications in team to 'are you better thasn LINT?'16:08
DocScrutinizer51the booklet has 270p, we managed to eat thru 57 today. will be fun on day316:10
DocScrutinizer51I already start feeling sick ;-D16:11
whitequarkDocScrutinizer51: I connected two modules simultaneously16:42
whitequarkthey work16:42
whitequarkalso, there's ~500mV ripple at the Vdd of each module (measured at its pin)16:43
whitequarkand a 700mV ripple at the power source (three AA batteries)16:43
whitequarkhow bad is that?16:43
DocScrutinizer51probably not too bad yet16:45
DocScrutinizer51though  you should make sure you use low ESR powersourse and thick wires for VDD16:46
DocScrutinizer51and GND16:46
DocScrutinizer51too high ESR is main culprit of strange annoying connection faults16:47
DocScrutinizer51most likely AA batteries might be a suboptimal power source16:51
whitequarkwell, I use my wires in packs of 316:52
DocScrutinizer51then OTOH you could add a 5000uF16:52
whitequarkeach one is .05 sq.mm, through16:52
DocScrutinizer514700 actually16:52
whitequarkalso, near to each module I added a low-ESR 100u tantalum cap and a 100n ceramic one16:53
DocScrutinizer51way too low for the 2A bursts16:54
DocScrutinizer51anyway, I'm wasted. May I'll be back in an hour or so16:55
DocScrutinizerhey, Adam gave a new schem to us :-)17:49
DocScrutinizersorry whitequark - did you say your wires are 0.05mm^2 ?18:00
DocScrutinizerif that's correct, you probably want to use 20..50 of them18:01
whitequarkDocScrutinizer51: er, not sure. I shoulda find a caliper somewhere...20:12
whitequarkDocScrutinizer51: btw, would you recommend to keep using a mechanical caliper, or are digital ones generally better (worse)?20:38
wpwrakwhitequark: some are as precise (and a lot more convenient). some are worse. ironically, the cheapest-looking digital one i have is very good.21:33
DocScrutinizerwhitequark: I have no experience, but I heard the electronic calipers need *a battery* ;-)21:59
whitequarkwpwrak: yeah, I observed the latter at times. For example, $1.5 chinese "switzerland" tweezers were way better than 5 times as expensive bought here...22:00
whitequarkDocScrutinizer: oh. yes. a battery. that answers the question.22:00
DocScrutinizersometimes for me that pretty much actually does22:00
viricI also dislike batteries22:01
viricwe want supercapacitors.22:01
DocScrutinizerlemme do the math:  battery: 2$, selfdischarge EOL: after 2 years the latest, number of usage during that period (YMMV): max 10 times avg. 22:03
DocScrutinizerso one usage would cost me 20ct22:03
viricnot to mention the ecological impact22:03
DocScrutinizerplus inconvenience of flat bat when I *really* need it22:03
whitequarkviric: do you like RoHS too?22:04
viricwhitequark: I don't know details of it22:04
viricwhitequark: I've only seen marketing22:04
whitequark... or maybe think that there is "damage to ozone layer" which is "harmful to the planet"?22:04
viricI think a digital caliper is more polluting than a mechanical caliper22:06
viricfor a very little win22:06
whitequarkon the topic of supercaps: we already have two kinds22:06
whitequark1) ionistors, but they kinda self-discharge in a few days22:07
whitequark2) rechargeable lithium batteries. have (almost?) the same look as the common coin-cell ones, but can be recharged with a small constant current; used in RTCs22:07
whitequarkthrough I don't know where one can buy the 2)22:07
whitequarkand afaik they can't be recharged in the "cellphone" mode, that is, go from 0% to 100% in a few hours22:08
whitequarkDocScrutinizer: for me, the problem with these batteries is that you'll have a hard time finding $RANDOM pcs of LR$RANDOM when you least want to deal with it22:09
wpwrakDocScrutinizer: i think my battery-powered one has been up for more than 2 years by now. still works great. probably hundreds of measurements in that time. i use it almost daily. ymmv indeed :)22:16
wpwrakDocScrutinizer: i don't quite like the short (~ 1 yr) battery life of my micrometer, though. but then, that one is kinda hard to read without electronics. (it has the traditional scale, too)22:18
wpwrak(and yes, that one gets about 10 uses per year on average. for cases where i really want to know and where i need reproducible pressure)22:20
whitequark... oh.22:57
whitequarkthis module has 2.8V inputs.22:57
whitequarkand I thought they were 3.3V.22:58
wpwrakbarbecue time ! ;-)23:03
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